Metal-organic frameworks (MOFs) are a growing class of organic-inorganic hybrid crystalline porous materials, showing high levels of structural and chemical diversity. They have a wide range of applications in gas adsorption and separation, catalysis, sensing, biomedicine and other fields. Due to their intriguing properties such as high porosity, adjustable pore size and tunable surface functionality, MOFs have been gaining popularity as a promising platform for integration of various organic/inorganic functional nanomaterials in a predictable and controllable way. The combination of MOFs and functional components offers a possibility to generate synergetic effect between functional units, thus leading to the creation of multifunctional materials with performance superior to each individual components. In this review, we summarized recent research progress on controllable synthesis of MOF composites. There are basically two strategies, including “bottle in ship” and “ship in bottle”. Following that, preparation methods including solution infiltration, deposition, solid grinding and template synthesis, were discussed in detail. Light-to-heat conversion materials have always been a research focus due to their important applications in solar powered water evaporation and near-infrared (NIR) excited bioimaging and noninvasive cancer treatment. MOFs can not only show intrinsic structure-dependent photoresponse activity, but also serve as porous supports to facilitate the stabilization and spatial distribution of photothermal nanoparticles. Recently, MOF composites with photothermal effects have aroused increasing attention in the fields like tumor diagnosis and treatment, bacterial disinfection and synergistic catalysis. This review mainly focused on the recent research progress on photothermal MOF composites. We discussed the integration of functional MOFs with various inorganic/organic photothermal nanoparticles (e.g. Au, Pt, porphyrin, polydopamine etc.), along with the structure and photothermal application of the composites. Research about MOFs based light-to-heat conversion is at the stage of rapid development. Finally, we also give a prospect to the future development of multifunctional and photothermal MOF composites.

Sodium ion batteries (SIBs) have been regarded as a very suitable electrochemical energy storage technology for large-scale energy storage due to its low cost and high safety. Suitable anode material is one of the keys to boosting the commercialization process of SIBs. Significantly, hard carbon (HC) anode is considered as the most practical anode material for SIBs due to its rich natural sources, low cost, non-toxic, environmentally friendly, and low sodium storage voltage. However, hard carbon anode also faces the problems of low initial Columbic efficiency, insufficient long cycle stability and poor rate performance, which restrict its practical application in SIBs. In recent years, extensive investigations have been done to improve the performance of hard carbon anode, herein, this review discusses the recent progress of performance optimization strategies of hard carbon anode from four aspects, including structure control, morphology design, interface manufacture, and electrolyte optimization and conducts an analysis of the merits and demerits of each optimization method. Moreover, this review also discusses the bottlenecks and challenges in the process of practical application of hard carbon anode for sodium ion batteries.

Sodium ion batteries have regained widespread attention in the field of large-scale electrochemical energy storage by virtue of their widely distributed and low-cost sodium resources. Among many of the cathode materials (layered, tunnel-like, polyanionic type and Prussian-blue type, etc.), layered transition metal oxide materials have received extensive research attention due to the features of high specific capacity, relatively good electrochemical reversibility, and rich and adjustable chemical composition. Sodium cobalt oxide is one of the most typical layered transition metal oxides. A lot of research has been done about sodium cobalt oxide since the 1980s. Although compared with other energy storage systems (such as lithium cobalt oxide materials which has the similar composition), sodium cobalt oxide does not take more advantage in electrochemical performance (like rate performance, cycle performance, etc.), but it can be observed from the charge and discharge curve that sodium cobalt oxide has undergone complex electrochemical processes, which means that it has a bunch of information on the degradation mechanisms during the charge and discharge processes. The correlation studies of the failure mechanism during the charging and discharging processes of sodium cobalt oxide (including the structure changes and the charge compensation mechanisms) are of great significance for the deep understanding of the layered oxide systems in sodium ion batteries. Therefore, on the basis of introducing the common crystal structure types and the synthesis phase diagram of sodium cobalt oxides, this article focuses on reviewing the structure changes (including phase transition and Na⁺/ vacancy ordering) and charge compensation mechanisms of sodium cobalt oxides with different crystal structures during the charging and discharging. At the same time, the correlation between the mechanisms above and electrochemical performance is discussed. This review aims to provide support for the in-depth study and establishment of the structure-activity relationship in the electrochemical processes of layered transition metal oxide cathode materials.

Hydrogen with remarkable energy density has attracted much attention as the green, sustainable chemical energy carrier and a substitute for traditional fossil fuels. The discovery of safe and efficient hydrogen storage materials for the transition to a hydrogen energy society is one of the biggest challenges for hydrogen energy applications today. Hydrous hydrazine (N₂H₄•H₂O), with its high hydrogen content (w=8.0%) and the advantage of CO-free hydrogen production, has significant advantages in hydrogen storage and release and is considered as a promising liquid-phase chemical hydrogen storage material. The development of efficient and highly selective catalysts is the key to release hydrogen from the decomposition of hydrous hydrazine. In the past decade, a lot of catalysts have been developed to improve the kinetic properties for hydrogen generation. In this review, we focus on the recent progress on catalyst design, synthesis and catalytic performance of the catalyst in hydrogen production from the selective decomposition of hydrous hydrazine. Ir, Rh and Ni monometallic catalysts were found to be very active toward the dehydrogenation of hydrazine. Among all the catalysts investigated, supported Pt-Ni, Rh-Ni and Pt-Co catalysts showed the highest activity. The mechanism of hydrazine decomposition was briefly analyzed. The cleavage of the N―H bond of N₂H₄ will facilitate the formation of H₂ and N₂, while N―N bond cleavage will result in the formation of NH₃ and N₂. In addition, we reviewed and discussed the strategies for promoting H₂ selectivity and activity of catalysts, such as the addition of strong base and/or alkaline carrier, formation of metal alloys, reduction of metal crystallinity and particle size, as well as the enhancement of the interaction between metal and support. The progress of this research may provide guidance for obtaining more active catalysts toward hydrogen production from nitrogen-based hydrides.

Membrane separation is very promising in solving energy and environmental challenges of separation process, and it has developed rapidly in recent decades. Metal-organic frameworks (MOFs) are a new type of microporous material with adjustable pores with uniform size, thus MOF membranes show promising potential for separation applications. With the rapid development of two-dimensional (2D) materials, 2D MOF membranes constructed with 2D MOF nanosheets, have attracted increasing attentions, where the pores of MOF could achieve molecular sieving, while both the nanochannels between the nanosheets and the pores of MOF nanosheets would provide mass transfer pathway for fast permeation. Therefore, 2D MOF membranes are expected to show both high permeability and selectivity, which might become a kind of high-performance membrane for industrial separations.

Photocatalytic reduction of CO₂ to valuable chemicals is an essential but still remains challenging. Metal-organic frameworks (MOFs) featuring high special surface area, large CO₂ adsorption uptakes, adjustable structures and function, have become a kind of promising porous materials for photocatalytic CO₂ reduction. However, MOFs often suffer from problems like short light harvesting range, rapid recombination of photogenerated carriers, resulting in lower activity. Here, graphene quantum dots (GQD) were supported on the Fe-based nano-sized MOFs, NH₂-MIL-88B(Fe), via electrostatic self-assembly strategy. GQDs were prepared by electrolysis of graphite rod in pure water firstly, and then centrifuged to remove the large species. Transmission electron microscope (TEM) reveals that ultrafine GQDs with 3 nm were obtained. Atomic force microscope (AFM) further demonstrates that the thickness of GQDs is around 0.34—1.5 nm (1—4 stacked layers). The MOFs, NH₂-MIL-88B(Fe), were synthesized with traditional solvothermal method, with a nano spindle shape of 250 nm×40 nm. The amino groups on MOFs provide strong electrostatic force with the carboxylic groups on GQDs, making the composite very stable and efficient electron transfer. High resolution transmission electron microscope (TEM) reveals that the nano MOFs were surrounded by tiny GQDs firmly. The bandgap of composite was determined by solid ultraviolet visible diffuse reflectance spectroscopy (UV-Vis DRS) and Mott-Schottky measurement, which indicate that it is thermodynamically appropriate for photocatalytic CO₂ reduction. Photocurrent experiments further demonstrate the composite is beneficial for the photogenerated electron-hole separation. Thus, the resulting GQD/NH₂-MIL-88B(Fe) composite showed much enhanced CO production rate (4 times) compared with the parent NH₂-MIL-88B(Fe), reaching 590 μmol/g under 10 h visible light irradiation with triethanolamine (TEOA) as sacrificial agent. The hugely improved photoreduction activity benefits from both the high CO₂ adsorption of MOFs and the enhanced separation of photogenerated electrons and holes. This work provides an avenue for preparation of MOFs based materials with high CO₂ photoreduction activity.

Azulene is a nonalternant and nonbenzenoid hydrocarbon with bright blue color and a dipole moment of 1.08 D, and has received increasing attention due to its unique electronic structure and physicochemical properties. Herein, we report the design and synthesis of two types of azulene-based [4]helicene 1a/1b and 2 that contain isoelectronic B—N and C=C units at the electron-rich 1-position of azulene unit, respectively. Formation of the helical scaffolds is executed by the introduction of boron and alkyne to flexible biaryl precursors, where the Lewis acidic boron and alkyne were employed as “glue” to join two subunits into fully fused scaffolds via electrophilic boronation and platinum-catalyzed cycloisomerization of alkyne at the 1-position of azulene unit, respectively. All of azulene-based helicenes were investigated by ultraviolet visible (UV-vis) absorption spectra, cyclic voltammetry (CV) measurements and density functional theory (DFT) calculations. Additionally, 1a was further characterized by single crystal structure analysis. The results suggest that the introduction of B—N unit changed the electronic structure of the conjugated aromatic framework, leading to a narrow HOMO-LUMO gap. Moreover, the B—N unit also affects the aromaticity of the π-system as revealed by nucleus-independent chemical shift (NICS) via time-dependent density functional theory (TD-DFT) calculation. The single crystal structure analysis demonstrates that 1a has a helically twisted framework and Plus (P)/Minus (M) enantiomers. However, the Gibbs activation energy (ΔG^≠(T)) of the enantiomerization at room temperature is too low to separate two enantiomers by chiral high performance liquid chromatography (HPLC). Furthermore, the B—N unit exhibits partial double bond character and the BN-containing six-membered ring shows weak aromaticity. 1a with a phenyl group exhibits the deboronization upon addition of trifluoroacetic acid (TFA) as well as a specific sensing behavior to fluoride ion. However, 1b shows no deboronization upon addition of TFA and no sensing behavior to fluoride ion due to its steric hindered mesityl (Mes) group, but has a reversible stimuli-responsiveness with acid and base, this proton-responsiveness is similar to all-carbon analogue 2.

In recent years, flexible organic and perovskite photovoltaic devices, organic thin-film transistors and medical sensors have been become popular fields of scientific research due to their advantages of wearable, flexible and semi-transparent properties. Employing conductive polymer with excellent mechanical properties is one of the effective pathways to realize these high-performance devices. In conducting polymers, poly(3,4-ethylenedioxythiophene) (PEDOT) and its aqueous dispersion poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) have been demonstrated to be the most promising alternative flexible materials of conventional metal oxides. It can be used as transparent electrode, hole transport layer, interconnects, electroactive layer, or motion sensing conductor in the device. This review focused on recent research advances of flexible devices for PEDOT and PEDOT:PSS applications, including various strategies to improve electrical conductivity, mechanical tolerance and long-term stability, and reveals the potential mechanisms of performance enhancement.

Photoredox catalysis is a practical and efficient synthetic technique that enables previously challenging or even impossible chemical transformations proceeding effectively. As one of the most prominent contribution to green chemistry, it provides a sustainable platform to the generation of high reactive radical species under mild reaction conditions. On the other hand, β-fluoro α-amino acids are significant structural units present in enzyme inhibitors, drugs and probes. Catalytic β-C(sp³)―H fluorination of α-amino acid represents a direct synthetic approach, but the harsh reaction conditions and the limited substrate scopes lead to high difficulty for these methodologies to being generalized to industrial application. Here, we report a novel and modular protocol that is via photoredox catalytic radical coupling. By using a dicyanopyrazine-derived chromophore (DPZ) as the photoredox catalyst, two readily accessible starting substrates, that are N-aryl glycine esters and α-fluoro-aryl acetic acid-derived redox-active esters (RAEs), can undergo single-electron oxidation and reduction, respectively. The resulting ester-substituted α-amino radicals and α-fluoro benzylic radicals then experience cross coupling, a highly reactive process in radical chemistry. As a result, a series of β-fluoro-α-amino acid derivatives were obtained in high yields. In this transition metal-free catalytic system, no extra oxidant or reductant is required, representing a redox neutral platform. General procedure for the synthesis of β-fluoro-α-amino acid derivatives is: to a flame dried Schlenk tube was sequentially added N-aryl substituted glycine esters 1 (0.4 mmol), RAEs 2 (0.2 mmol), DPZ (0.004 mmol, 1.42 mg), tetra-n-butyl- ammonium bromide (0.04 mmol, 12.9 mg), sodium dihydrogen phosphate (0.40 mmol, 48 mg) and cyclopentyl methyl ester (CPME) (4 mL). Then degassed three times by freeze-pump-thaw method. The reaction mixture was stirred under an argon atmosphere at 25 ℃ irradiated by a 3 W blue LED for 48 h. After completion of the reaction, the reaction mixture was directly loaded onto a short basified silica gel column, followed by gradient elution with petroleum ether/ethyl acetate (V/V, 8/1). Removing the solvent in vacuo, afforded products.

Axially chiral compounds represent an important class of chiral molecules. In this regard, many methods have been developed to access these compounds. However, efficient methods for the synthesis of axially chiral styrenes are limited to date, mainly due to their relative instability compared to axially chiral biaryl compounds. Iridium-catalyzed asymmetric allylic substitutions have evolved as a powerful tool in constructing C―C or C―X bonds at the allylic position. We developed an efficient sequential strategy to access a series of axially chiral styrenes by iridium-catalyzed allylic substitution and central-to-axial chirality transfer via olefin isomerization. With the iridium complex derived from [Ir(cod)Cl]₂ and Alexakis ligand L1 as catalyst, and β-naphthol as nucleophiles, a broad range of axially chiral styrenes were obtained with moderate to excellent yields (28%~97% yields) and enantioselectivity (59%~98% ee). A general procedure for the asymmetric allylation of β-naphthol is described as the following: A flame-dried Schlenk tube was cooled to room temperature and filled with argon. To this flask were added [Ir(cod)Cl]₂ (2.6 mg, 0.004 mmol, 2 mol%), (S,S,S_a)-L1 (4.8 mg, 0.008 mmol, 4 mol%), freshly distilled tetrahydrofuran (THF, 0.5 mL) and propylamine (0.5 mL). The mixture was stirred at 50 ℃ for 30 min and then the low-boiling solvents were removed in vacuo to give a pale yellow solid. The solid was stirred at 50 ℃ again under vacuum until it became a powder. After that, β-naphthol 1 (0.22 mmol, 1.1 equiv.), allyl carbonate 2 (0.2 mmol, 1.0 equiv.), 1,4-diazobicyclo(2.2.2)octane (DABCO) (67.3 mg, 0.6 mmol, 3.0 equiv.) and freshly distilled Et₂O (2.0 mL) were added to this flask under argon atmosphere. The reaction mixture was stirred at 20 ℃ until the starting material was consumed (monitored by thin layer chromatography, TLC). The crude reaction mixture was diluted with water (5 mL), and extracted with dichloromethane (DCM, 5 mL×3). The organic layers were collected, dried over Na₂SO₄ and then concentrated in vacuo to afford the crude product. The residue was purified by preparative TLC to afford the product.

Coupling or condensation reagents that could be used to promote the condensation of carboxylic acids with amines to furnish amide bonds play crucial roles in solid phase peptide synthesis (SPPS) of peptides and peptide-based derivatives. Compared with traditional coupling reagents used in SPPS such as 1-hydroxy-7-azabenzotriazole (HOAt) and 1-hydroxybenzotriazole (HOBt), the novel N,N'-diisopropylcarbodiimide (DIC)/ethyl 2-cyano-2-(hydroxyimino) acetate (Oxyma) condensation system has advantages of inexpensiveness, safety, high coupling efficiency, low racemic rate, and compatibility with manual and automatic peptide synthesis represented by microwave-assisted SPPS. However, the effects of different reaction temperatures (e.g. 28, 50, and 75 ℃) on the coupling efficiency of DIC/Oxyma and on the easily oxidized amino acids such as methionine (Met) remain to be further investigated. The transient receptor potential ankyrin 1 (TRPA1) channel plays an important role in temperature perception, auditory perception, and inflammatory pain. As a novel non-covalently TRPA1-specific agonist, Wasabi Receptor Toxin (WaTx) that consists of 33 amino acid residues and two pairs of disulfide bonds is considered as an important molecular tool to study the opening mechanism and function of TRPA1. In this study, 2-(6-chloro-1H-benzotriazole-1-yl)-1,1,3,3-tetramethylaminiumhexa-fluorophosphate (HCTU)/N,N'-diisopropyl- ethylamine (DIEA) and DIC/Oxyma condensation systems were separately utilized to explore the synthetic efficiency of linear WaTx and the oxidative degree of Met residues at different temperatures. The robustness of DIC/Oxyma condensation system was validated by the rapid manual synthesis of linear WaTx. The one-step and two-step oxidative folding strategies were separately applied for the construction of two pairs of disulfide bridges, affording the active WaTx, which was further confirmed by circular dichroism and calcium fluorescence assay. In this study, a moderate, efficient synthesis and renaturation folding method of WaTx was established. Moreover, the effects of different reaction temperatures on the synthetic efficiency of DIC/Oxyma and on amino acid residues oxidization were compared for the first time. From the aspects of reaction efficiency (represented by the timescale of the overall Fmoc deprotection-washing-amino acid coupling SPPS cycle), amino acid residues oxidization and synthetic cost, n(Fmoc-amino acid):n(DIC):n(Oxyma)=3:6:3 under 50 ℃ should be the ideal reaction condition. This work provides both an imperative complement for SPPS and a particularly useful strategy for the manual efficient synthesis of disulfide-containing peptides with easily oxidized groups.

The worldwide outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in the infection even death of people all over the world, which has gravely affected our daily life. Globalization of trade and convenient transportation immensely accelerate the propagation of the epidemic, which brings severe difficulties to prevent the epidemic. Therefore, rapid and accurate diagnosis of infected persons and screening of asymptomatic persons play an important role. At present, the most widely used method for the detection of SARS-CoV-2 is reverse transcription-polymerase chain reaction (RT-PCR), which still has some problems including complicated sample storage and transportation, complex operations and so on. These shortcomings cause the hindrances to achieve fast, simple, efficient diagnostic testing under the normalization of the epidemic. In the past few years, with the development of nanotechnology, bio-sensing methods based on nano photonics have become a research hotspot. Label-free optical methods have been widely explored for bio-sensing including virus detection, such as surface plasmon resonance (SPR), surface enhanced Raman scattering (SERS), whispering gallery mode (WGM) and colorimetry. These approaches offer available alternatives to improve the speed, sensitivity, and accuracy of optical bio-sensing, owing to the enhanced interaction between the nanostructure and the biomarkers. This review summarizes these nano photonics-based bio-sensing technologies for the detection of SARS-CoV-2. Moreover, the detection mechanism of biomarkers by nano photonics is explained, and the further development trends are discussed. In view of the difficulties in manufacturing nano photonics structures, a new strategy of large-area preparation of nano photonics structures using nano green printing technology is proposed, which provides theoretical and technical support for accurate and effective prevention and control of the epidemic diseases.

The third-generation energy electro-optical technology, perovskite solar cells (PSCs), have risen fast over the past decade. In view of the characteristic of intrinsic-semiconductor of organic-inorganic hybrid perovskite materials, as well as the multilayer planar architecture of PSC devices, the hole transport materials (HTMs) based on organic small molecules were introduced PSCs to make up of p-type layer, by which not only full-solid state PSCs were established, but also the highly efficient and stable PSC devices were attained. Currently, spiro-OMeTAD (2,2′,7,7′-tetrakis[N,N-di(4-methoxy- phenyl)amino]-9,9′-spirobifluorene) is still used as an universal benchmark material in the hole-transporting layer of PSCs, meanwhile the researches have make great effort to analyze and to improve the spiro-OMeTAD. For the prevailing molecule, the three-dimensional core of spirofluorene (SBF) offers a platform to integrate more hole-transporting units with less occupied space, and arylamine groups act as high electroactivity units due to their excellent p-type property. However, the classical SBF core has two major drawbacks: expensive preparation cost and monotonous modification positions, therefore the improvement orientation of spiro-OMeTAD is focused on the arylamine moieties. Along with the developments of molecular design of HTMs and corresponding synthetic methodology, a series of SBF-like aromatic-skeletons have been springing up and stepping into the field of HTMs in recent five years, e.g. spiro[fluorene-9,9′-xanthene], spiroacridine, spirothioxanthene and so on. These advancements expand the design space of HTM molecules, and enhance the efficiency and stability of PSCs. In consequence, we put eyes on the HTMs containing spiro aromatic-skeleton, and seek the structure elements of highly efficient materials. In this review, the high performance HTMs have been classified and summarized according to the type of spiro structure, further, their design solution and structure-performance relationship have also been refined. It is expected that the summarization and condensation would provide valuable strategies for HTMs design and promote the development of highly efficient and long-life PSCs towards practical application.

Allylic chiral centers are widely present in natural products and pharmaceutically active molecules, and play a vital role in the construction of organic compounds through pericyclic reactions, oxidations or reductions and other transformations. The transition metal-catalyzed asymmetric addition or coupling reaction using alkenyl metal nucleophiles is one of the most attractive strategies for the synthesis of these structures. Among the many metal catalysts, earth-abundant transition metals such as iron, cobalt, nickel and copper have been used to replace precious metals such as rhodium and palladium, and have gained attention for use in enantioselective alkenylations. Indeed, remarkable advances have been achieved with these catalysts due to their unique catalytic activity, low toxicity and environmentally friendliness. The earth-abundant transition metals are known to undergo facile one electron oxidation state changes. In the reaction process, the earth-abundant transition metals have the ability to undergo two-electron transfer and single-electron transfer processes, therefore they have more valence changes and catalytic pathways which can be exploited. Based on this, this article will review the latest research in earth-abundant metal-catalyzed enantioselective alkenylation using alkenyl metal reagents. It is divided into four sections consisting of cobalt-catalyzed enantioselective alkenylations using alkenyl metal reagents, nickel-catalyzed enantioselective alkenylations using alkenyl metal reagents, copper-catalyzed enantioselective alkenylations using alkenyl metal reagents, and other earth-abundant transition metals catalyzed enantioselective alkenylations using alkenyl metal reagents.

Cyclopentadithiophene (CPDT) derivatives, as a class of fluorene-like molecular building blocks that have a wide range of applications in the design of organic optoelectronic materials due to their easily molecular tailoring, electron-rich, low band gap, high electrical conductivity and good charge transport properties in the field of plastic electronics. At the same time, cyclopentadithiophene is easy to carry out structural modification, which can introduce various functional groups conveniently and quickly, and can expand a variety of derivatives. Cyclopentadithiophene can be divided into six structural isomers based on the position of the S atom on thiophene. Among these structural isomers, there are many reports on 4H-cyclopenta[2,1-b:3,4-b']dithiophene derivatives. In this article, we review mainly the synthesis and properties of 4H-cyclopenta[2,1-b:3,4-b']dithiophene derivatives and applications in organic solar cells (OSCs), organic field-effect transistors (OFETs). The research progress in organic light-emitting diodes (OLEDs) and other fields is also comprehensively summarized. The perspectives of the gridochemistry of CPDT-based organic semiconductors will be made finally.

²¹¹At, with a half-life of 7.2 h, is an excellent radionuclide being investigated for use in targeted alpha therapy as the result of very high linear energy transfer. However, the production of ²¹¹At is limited by ²¹⁰At, because ²¹⁰At decays to produce long half-life (138.4 d) extremely toxic daughter ²¹⁰Po. The production of ²¹¹At via ²⁰⁹Bi(α,2n) nuclear reaction and ²¹⁰At via ²⁰⁹Bi(α,3n) nuclear reaction, as the energy of incident α-particle increases, the ratio of N(²¹⁰At)/N(²¹¹At) increases. In this research, the α-particle is provided by the Chinese Accelerator Driven Sub-critical System (ADS) Front-end Demo Linac at Institute of Modern Physics, Chinese Academy of Sciences. The technical process of ²¹¹At produced was studied systematically, including accelerator irradiation, separation by dry distillation method, quality analysis, and monoclonal antibody labeling. The bismuth targets were irradiated with α-particle by 28.18, 28.34, 28.48 28.92 MeV, and the target chamber adopts an inclined target with water cooling to improve the cooling effect. The dry distillation separation was carried out at a high temperature of 850 ℃, oxygen as the carrier gas, chloroform and ethanol as eluent, and the chloroform solution containing ²¹¹At was blow dry with nitrogen. The results showed that the total recovery of dry distillation separation of ²¹¹At reached 78.53%. After separation, the quality analysis of ²¹¹At was performed using a high-purity Ge-detector, alpha energy spectrometer, and mass spectrometer. The obtained solid ²¹¹At had high specific activity, radionuclide purity and chemical purity, where the content of impurity elements Bi, Cu, Zn, and Al was less than 100 ng/GBq, and the ratio of N(²¹⁰At)/N(²¹¹At) was less than 10^–5 when the incident particle energy is below 28.2 MeV. Finally, the labeling of ²¹¹At-nimotuzumab was realized through N-succinimidyl-3-(trimethylstannyl)benzoate, and the labeling rate was 94.86%. Based on this research, a set of simple and efficient separation methods was established, which laid a good foundation for the subsequent production and application of ²¹¹At in China.

Over the past two decades, organic solar cells (OSCs) have been developed rapidly with the power conversion efficiency rapidly rising from less than 5% to over 18%, which is mainly promoted by the development of various new donor and acceptor materials. As a typical electron-deficient penta-heterocycle, benzotriazoles (BTAs) derivates a variety of high-performance photovoltaic materials, including polymer donor, small-molecule donor materials, as well as non-fullerenes acceptor and polymer acceptor. Among them, the J series of polymer donors and Y series of non-fullerenes acceptors are typical examples, and thus are specially highlighted in this review. Meanwhile, molecular design strategies of those BTA-based photovoltaic materials have also been discussed. It shows that donor-acceptor (D-A) conjugated strategy is still the most efficient thus far, where A units is the BTA unit or its derivatives, and D units commonly used in BTA-based photovoltaic materials are benzodithiophene, benzodifuran, dithienosilole, indacenodithiophene, thiophene,etc. The D-A strategy is both applied for donor molecules (with the molecular structure of D-A, D-π-A-π, D-A-D-A-D,etc.), and for acceptor molecules (with the molecular structure of A-D-A, A-π-D-π-A, A-DAD-A,etc.). By adjusting their molecular structures and/or pairing of differential D and A units, various properties such as absorption band and energy levels of molecules, as well as the morphology and charge carrier mobilities in OSCs can be well controlled. Furthermore, through side-chain engineering, such as flexible side-chains (alkyl, alkoxy, alkylthiol, alkylsilyl,etc.), conjugated side-chains (substituted-thiophene or benzene,etc.), electron-withdrawing groups (F atoms, Cl atoms, dicyanomethylene,etc.), their photovoltaic properties can be further regulated. Here, this review focuses on the research progress on BTA-based photovoltaic materials and related molecular design strategies developed in recent years, and also presents perspective on its future development.

Micro/nano materials have unique properties that are different from macro materials because of their small scale, and these materials have diverse applications in many fields. In recent years, with the unique advantages of low consumption, high efficiency, high throughput, miniaturization, integration and automation, microfluidic technique has aroused widespread concerns in the synthesis field of micro/nano materials. In this review, the commonly used microreactors are classified from two perspectives of structural form and reaction method, and the application of microfluidic technique in the synthesis of micro/nano materials including inorganic materials, organic materials and composite materials are introduced. In addition, the main development trends in the future are prospected in this review. Microfluidic technique has provided new ideas and methods for the synthesis of micro/nano materials, which has rich possibilities and great potentials in both industrial production and academic research.

N-arylsulfonyl hydrazones were a kind of stable diazo surrogates in organic synthesis. Among them, N-tosylhydrazones occupied main position in the research of carbene chemistry, and many reactions involving N-tosylhydrazones and reviews were published. In recent years, the chemical reactions involving electron-withdrawing groups (EWG)-substituted N-arylsulfonylhydrazones as milder diazo surrogates have been developed rapidly. However, these reactions were not summarized. Therefore, this review focuses on the research progress on EWG-substituted N-arylsulfonylhydrazones used as diazo surrogates in organic synthesis reactions, and emphasized the coupling, cyclization, insertion, multicomponent and Doyle-Kirmse reaction involved N-o-nitrobenzenesulfonylhydrazides and N-o-triftosylhydrazones.

The mechanism of Cu catalyzed intramolecular Ullmann C―O coupling reaction of 2-(2-iodophenyl)ethan-1-ol was proposed and verified by density functional theory (DFT). All of the structures have been fully optimized using N,N-dimethylformamide as solvent by the Gaussian16 package with the B3LYP functional. In the process of optimization, the standard 6-31G (d) basis set was used for C, O, N and H atoms, while Stuttgart basis set (SDD) was used for Cu and I atoms. Grimme D3 method was used for dispersion correction of all calculations. The frequency calculation is carried out at the same theoretical level to determine whether the calculated geometry is minimum (zero imaginary frequency) or transition states (one imaginary frequency). The extra single-point calculations, including solvation and dispersion corrections, on the optimized geometries were employed to obtain improved Gibbs energy values with B3LYP/def2-tzvp in the continuum solvation model based on density (SMD). The intrinsic reaction coordinates (IRC) of all transition states were calculated to confirm that the structure connects the reactant and the product. The calculation shows that catalytic cycle starts from the in-situ formation of cuprous complex, and cuprous complex undergo oxidative addition to give Cu(III) complexes. The Cu(III) complex is coordinated with alcohol to form a four-coordinated Cu(III) complex. Then the substrate is activated by O-halogen bond, and the intermediates underwent ligand exchange to form another Cu(III) complexes, which transmits the desired alkyl aryl ethers and regenerates the catalyst cycle. Quantitative calculation shows that the reaction mechanism can be divided into four steps: (1) oxidative addition, (2) coordination effect, (3) ligand exchange, (4) reductive elimination. First, it was found that tert-butoxide was not only a base, but also a catalyst species. Secondly, it is pointed out that ligand exchange is the rate-determining step of the whole reaction. Before the ligand exchange, it is activated by a slowly approaching tert-butoxide to form a halogen bond (XB). The calculated results are in good agreement with the experimental data, which proves the rationality of the calculation mechanism and helps to explain the Ullmann reaction mechanism.

Radiotherapy is a traditional treatment method that utilizes high-energy radiation to inhibit cancer cells and has been widely used in the treatment of malignant tumors. However, high-energy radiation can not only cause damage to tumors, but also cause side effects to normal tissues. Although some small-molecule radioprotection agents have been used in clinics, their short blood circulation time and faster metabolism greatly reduce the protective effects. In the last twenty years, with the rapid development of nanotechnology in biomedicine, radioprotection nano-agents have provided new candidates for improving the protective effect. Rational design of radioprotection nano-agents is demanded to solve the drawbacks of existing small-molecule radioprotection agents. In view of the many advantages of nanomaterials for radioprotection, this review summarized the common design strategies of nanometer radioprotection materials, and analyzed the pathogenic mechanism of common radiation-induced diseases as well as the treatment of various radiation-induced diseases by radioprotection nano-agents. In addition, this review also discussed the challenges and future prospects of nanomaterial-mediated radioprotection during radiotherapy.

The synthesis of stable single-metal site catalysts with high catalytic activity and selectivity with a controllable coordination environment is still challenging. Due to the different electronegativity of different coordination atoms (N, P, S, etc.), adjusting the coordination atom type of the active metal center is an effective and wise strategy to break the symmetry of the electron density. We adopted a cation exchange strategy to synthesize two Cu single-atom catalytic materials with different coordination structures. This strategy can change the coordination environment of Cu single atom by changing the different organics wrapped around Cu-CdS. This strategy mainly relies on the anion skeleton of sulfide and the N-rich polymer shell to produce a large number of S and N defects during the high-temperature annealing process, and the precise synthesis of a single-metal Cu site catalyst material with rich edge S and N double modification. In these two materials, one single Cu atom has double coordination of sulfur (S) and nitrogen (N), and the other single Cu atom has only a single S coordination. The first shell coordination number of Cu central atom is 4, the structure of Cu-S/N-C is Cu-S₁N₃, and the structure of Cu-S-C is Cu-S₄. The results show that the catalytic performance of Cu-S/N-C in the hydrogenation of nitrobenzene compounds is much better than that of Cu-S-C, that is, the Cu monoatomic materials with S and N double-modified metal sites has better hydrogenation activity than single S-modified metal sites. After 20 min of reaction, under the catalysis of Cu-S/N-C, the conversion rate of nitrobenzene reached 100%, and the activity did not decrease significantly after being recycled for 5 times. It shows that the Cu-S/N-C catalytic material with a single-atom structure we synthesized has good stability. This discovery not only provides a feasible method for adjusting the coordination environment of the central metal to improve the performance of single-atom catalytic materials, but also provides an understanding of the catalytic performance of heteroatom modification.

Electrocatalytic CO₂ reduction (ECR) into high value-added chemical products has been regarded as an effective strategy to release environmental crisis caused by high concentration of CO₂ in the atmosphere, because of its mild operation conditions and the ability to use renewable energy sources as power. Metal-nitrogen-doped carbon-based nanomaterials have been demonstrated as excellent catalysts for electrochemical reduction of CO₂ due to their high selectivity and low cost. However, it suffers from the problem of low Faradaic efficiency at high current density, which limits their further applications. In addition, the silver-based catalysts have good catalytic activity for the electrochemical reduction of CO₂ to CO, but they can only achieve high selectivity under high overpotentials. The synergistic effect in the multi-component system provides a new idea for the design of efficient electrocatalysts for carbon dioxide reduction. Herein, we first elaborately design and prepare an ordered macro-/mesoporous nickel-nitrogen-doped carbon (Ni-N-OMMC) supported silver nanoparticles composite (Ag/Ni-N-OMMC) by the use of silica colloidal crystal as the hard template and triblock copolymer Pluronic F127 as the mesoporous structure-directing agent, and study the electrocatalytic CO₂ reduction performance. Due to the confinement effect, the small silver nanoparticles are successfully loaded on the Ni-N-OMMC support by in-situ chemical reduction. Compared to Ni-N-OMMC, Ag/Ni-N-OMMC exhibits better electrocatalytic activity. The Faradaic efficiency of CO is as high as 98.7% when the potential is –0.7 V vs. reversible hydrogen electrode (RHE) in 0.1 mol•L^–1 KHCO₃ electrolyte. Moreover, Ag/Ni-N-OMMC has a wide operating voltage range with the Faradaic efficiency of CO over 90% at –0.7~ –1.0 V, and shows a high current density of CO (33.29 mA•cm^–2) at –1.0 V. The excellent ECR performance of Ag/Ni-N-OMMC may be attributed to the synergistic effect between Ag nanoparticles and the Ni-N-OMMC support with abundant Ni-N _x active sites, as well as the high specific surface area and efficient mass/charge transfer provided by the three-dimensional interconnected ordered macro-/mesoporous structure. This study provides an idea for future design and preparation of metal-carbon composite electrocatalysts with high activity and selectivity.

In view of the importance of sulfonyl groups in organic molecules, the introduction of sulfonyl groups and the synthesis of sulfonyl compounds have been widely reported. Among them, the synthesis of sulfonylhydrazides has attracted much attention because of their biological activities in antitumor and antibacterial activities. Here, we developed a photoinduced reaction of potassium alkyltrifluoroborates, DABCO•(SO₂)₂ (1,4-Diazabicyclo[2.2.2]octane, DABCO), and aroylhydrazides under visible light irradiation, which obtained N'-acyl-N-alkylsulfonylhydrazides in moderate to good yields in one-pot. This reaction works in a green and mild way with a broad substrate scope. Mechanistic study shows that after giving rise to N-acyldiazenes via the oxidation of aroylhydrazides, the transformation is initiated by alkyl radicals generated in situ from potassium alkyltrifluoroborates in the presence of photocatalyst. The subsequent insertion of sulfur dioxide and alkylsulfonylation of N-acyldiazenes with alkylsulfonyl radical intermediates afford the corresponding N'-acyl-N-alkylsulfonyl- hydrazides. General procedure for visible-light photocatalytic alkylsulfonylation of aroylhydrazides with alkylsulfonyl radicals: to a solution of aroylhydrazides 1 (0.2 mmol) and K₂CO₃ (0.3 mmol) in MeCN (2.0 mL) was added I₂ (0.12 mmol). The reaction was stirred for 3 h at room temperature, then quenched with sat. aq. Na₂S₂O₃ (15 mL). The layers were separated and the aqueous layer extracted with dichloromethane (DCM) (15 mL×3). The combined organic layers were then washed with brine (15 mL), and dried over Na₂SO₄. Evaporation of the solvent under reduced pressure afforded the crude N-acyldiazenes, which was used in the subsequent transformation without further purification. The crude N-acyldiazenes were combined with potassium alkyltrifluoroborates 2 (0.24 mmol), DABCO•(SO₂)₂ (0.2 mmol) and 9-mesityl-10-methylacridinium perchlorate ([Mes-Acr]ClO₄) (0.004 mmol) in a tube. The tube was evacuated and backfilled with N₂ three times before the addition of MeCN (2.0 mL). The mixture was then placed around blue light emitting diodes (LEDs) (30 W) with a distance of 10 cm, and was stirred under blue light irradiation for overnight at room temperature. After completion of reaction as indicated by thin layer chromatography (TLC), the solvent was evaporated and the residue was purified directly by flash column chromatography (V(n-hexane)/V(ethyl acetate)=5∶1—2∶1) to give the N'-acyl-N-sulfonylhydrazides 3.

Solid-state lithium batteries (SSLBs) are considered to be an important development direction for the next generation of power batteries due to their safety and potentially high energy density. However, there are several challenges including low ionic conductivity, poor stability/incompatibility between electrodes and electrolytes at present. To improve the performance of SSLBs, it is very important to clarify the dynamic evolution of electrodes, solid electrolytes, and their interfaces in the cycle process. In the past few decades, the emergence of various advanced in-situ characterization technologies has improved the understanding of the working mechanism of high-performance lithium batteries and promoted further development. Herein, we present a comprehensive overview of the in situ research progress of atomic force microscope, electron microscope, X-ray microscope and other imaging characterization techniques, and component analysis techniques such as Raman spectroscopy, X-ray technology, and neutron depth analysis in recent years. The focus is on the application research of various characterization techniques in morphology and composition evolution processes of the SSLBs, including the phase transformation and deformation of the cathode materials, the deposition/dissolution of lithium metal, the growth of lithium dendrites, the structure evolution of solid electrolytes, and the formation of the solid electrolyte interphase, which strengths the understanding of solid-state lithium batteries.

Three-component difunctionalization reaction is one of the most important ways to construct C―C bond or C―X bond in organic chemistry. It has the characteristics of high efficiency by introducing two new chemical bonds into the substrate at the same time. Most current reports on the difunctionalization follow the interest of unsaturated bonds such as olefins. Olefins exist in many natural products and play an important role in organic synthesis, and they are widely used in pharmaceutical manufacture, chemical industry and experimental study. Therefore, the study on the difunctionalization reaction of olefins is of a great potential application. In this paper, we report an α,β-diarylation reaction of α,β-unsaturated ald- imines with Ni(COD)₂ as catalyst, and aryl magnesium bromides and aryl bromides as the arylating reagents. This method offers a new straightforward strategy to introduce two different aryls concurrently and provides a readily access to various triphenyl-substituted propionaldehydes. Moreover, the synthesis of natural product Quebecol (2,3,3-tri-(3-methoxy-4- hydroxyphenyl)propan-1-ol) can be realized by using the established reaction as the core step. Mechanistic studies revealed that the reaction underwent a process of nucleophilic addition, metal exchange and reductive elimination. A general procedure of this nickel-catalyzed diarylation is as follows: To a 25 mL Schlenk tube equipped with a magnetic stir bar were added an aldimine (0.20 mmol), aryl bromide (0.40 mmol), PPh₃ (0.04 mmol, 20 mol%) and Ni(COD)₂ (0.02 mmol, 10 mol%). After being evacuated and backfilled with nitrogen for three times, dry THF (1.6 mL) and aromatic Grignard reagent (0.4 mL, 1.0 mol/L in THF, 0.40 mmol) were added to the tube. The reaction mixture was stirred at 80 ℃ under an nitrogen atmosphere for 12 h and quenched with 3 mol/L HCl (aq.). The mixture was extracted with ethyl acetate (20 mL×3). The combined organic layers were washed with brine, dried over anhydrous Na₂SO₄, filtered and concentrated under reduced pressure. The residue was purified by flash column chromatography on silica gel to afford the desired triphenyl-substituted propionaldehydes.

To study the influence of the construction of heterojunction on the visible-light response range and the photo-generated charge carriers separation efficiency of TiO₂, two dimensional/three dimensional (2D/3D) ZnIn₂S₄/TiO₂ heterojunctions were synthesized by high-temperature calcination followed by a facile oil bath method, and were investigated for the photodegradation of Rhodamine B (RhB) and tetracycline (TC). X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) were applied to investigate the composition, crystal structure, and morphology of the as-prepared specimens. UV-visible diffuse reflectance spectra (UV-vis DRS), electrochemical impedance spectroscopy (EIS), photocurrent measurement, photoluminescence (PL) spectra, and first-principles calculation were also performed to investigate the photoelectric property. The results showed TiO₂ maintains the morphology of metal-organic frameworks (MOFs) with narrow visible-light response range and high photo-generated charge recombination efficiency. After coupling with ZnIn₂S₄ nanosheets, a larger specific surface area was obtained with offering more active sites for photocatalytic reaction. The band gap of the composite was reduced from 3.23 eV of TiO₂ to 2.52 eV of ZnIn₂S₄/TiO₂-II, and thus obtaining an extended visible-light response range and enhancing visible light utilization rate. The energy band structure acquired from the UV-vis DRS and XPS valence band spectra indicated a construction of type II heterojunction in the ZnIn₂S₄/TiO₂ composite, and thus improving the separation and transfer efficiency of photo-generated carrier pairs, which was confirmed by the PL, EIS and photocurrent test results. Under the visible light, ZnIn₂S₄/TiO₂ displayed significantly enhanced photocatalytic activity than bare TiO₂ and ZnIn₂S₄. Among of ZnIn₂S₄/TiO₂ photocatalysts, ZnIn₂S₄/TiO₂-II possessed the highest photocatalytic degradation efficiency (93%) of RhB solution within 60 min, which was nearly 18 and 2 times higher than pristine TiO₂ and ZnIn₂S₄, respectively. Besides, the ZnIn₂S₄/TiO₂-II photocatalyst also showed enhanced photocatalytic activity for TC degradation than pure TiO₂ and ZnIn₂S₄. The cycle experiment showed that the ZnIn₂S₄/TiO₂-II photocatalyst could maintain good reusability, and it could still photodegrade 83% RhB after 5-cycle test. This work demonstrates that constructing 2D/3D ZnIn₂S₄/TiO₂ heterojunction based on MOFs-derived TiO₂ is an efficient strategy for significantly enhancing the photocatalytic activity of TiO₂.

Copper-based nanomaterials show widespread applications in the fields of luminescence and (bio)chemical sensing. Copper nanoclusters as a new class of nanomaterials have attracted extensive attention due to their atomic-level structure, but the syntheses of stable atom-precise copper clusters with good properties are still challenging. In this work, we have successfully prepared a novel mercaptoimidazole-stabilized copper(I) nanocluster: [Cu₁₃(SR)₁₂] NO₃ (Cu₁₃ NC, where RSH=2-mercaptobenzimidazole) by introducing the reducing agent (NaBH₄) in an acetonitrile-methanol solution of copper nitrate and RSH. The presence of NaBH₄ not only reduced Cu(II) to Cu(I) but also provided a reducing system to avoid the reversed oxidation. The structure and composition of Cu₁₃ NC have been collectively elucidated by X-ray crystallography and electrospray ionization mass spectrometry (ESI-MS). The metal framework of Cu₁₃ NC can be seen as three triangular bipyramids sharing one or two vertices, which are surrounded by 12 thiolate ligands as protecting agents through a simple bridging mode. Since the counterions in the crystal lattice are highly disordered and could not be located, the existence of NO₃^- has been confirmed by infrared spectroscopy and ESI-MS. Cu₁₃ NC exhibits good stability under ambient conditions and shows bright-red emission in the solid state (λ_em=627 nm). The long-life emission in the order of microseconds and large Stokes shift (≈280 nm) indicate that the luminescence of Cu₁₃ NC is a spin-forbidden triplet phosphorescence. The absolute quantum yield of the solid-state Cu₁₃ NC was calculated to be 1.36%. Meanwhile, there are two exposed copper atoms at each end of the structure, endowing Cu₁₃ with good electrochemical activity. The test confirmed that Cu₁₃ NC shows prompt response, and great selectivity in electrochemical detection of H₂O₂, making it a low-cost advanced H₂O₂ sensing material. This work provides an opportunity to investigate the structure-optical and electrochemical property relationship of copper clusters.

In this work, a kind of high-performance electrochemiluminescence (ECL) material was obtained with the assistant of metal-organic framework (MOF) structure, which realized the highly ordered assembly of ECL molecules in MOF structure, developing a new strategy of synergistically enhanced ECL. Specifically, it combined the advantages of both the pore confinement effect and the highly ordered assembly of ECL molecules in micro/nano space to enhance the ECL intensity and reaction efficiency. The proposed MOF material (abbreviated as Zr-TCPE) with excellent ECL performance was synthesized by a simple solvothermal synthesis technique employing the non-coplanar molecule 1,1,2,2-tetrachlorophenol- (4-carboxylic benzene)ethylene (H₄TCPE) as ligand and Zr₆ clusters through coordination interaction. Zr-TCPE with the porous structure can not only promote the mass transport and electron transfer in the confined micro/nano spaces, but also reduce the nonradiative relaxation and filtering effect as the H₄TCPE ligands were fixed on the rigid metal frame, restricting the free vibration/rotation and tight packing. Compared with the H₄TCPE micro/nano crystals prepared by reprecipitation method, the ECL intensity and efficiency of the Zr-TCPE increased by 3.46 times and 17.44 times with potential from 0 V to 1.4 V at 300 mV/s in 2 mL of detection solution (containing 18 mmol/L triethylamine, pH 7.4), respectively. The ECL biosensor was constructed according to the successive assembly of (i) the Zr-TCPE as ECL material, (ii) silver nanoparticles (Ag NPs) as immobilization matrix of concanavalin A (Con A) and (iii) the Con A as a cells trapping agent, which achieved the in situ monitoring of hydrogen peroxide (H₂O₂) released from the tumor cells under the stimulative effect of phorbol 12-myristate 13-acetate (PMA). Furthermore, the ECL biosensor could rapidly distinguish cancer cells from normal cells. What is more, the ECL biosensor is also suitable for the detection of H₂O₂ released from the various tumor cells. The prepared Zr-TCPE, as the combination of strong ECL emission, easy preparation and good biocompatibility, was expected to be a kind of popular luminophors for the clinical detection of tumor cells.

With the advance of industrialization of human society, fossil energy has been overconsumed, and excessive carbon dioxide has been discharged into the atmosphere, resulting in energy crisis and environmental issues. The preparation of high value-added fine chemicals by electrocatalytic reduction of carbon dioxide is one of the directions to explore the establishment of artificial carbon cycle, which has attracted extensive attention in fundamental research and industrial applications. Structural design and preparation of electrocatalysts with high activity, selectivity and stability are of great significance to achieve efficient catalytic performance for carbon dioxide reduction. In recent years, many studies have reported the structural design ideas and application cases of catalyst and electrode materials, and remarkable progress has been made. In this review, the regulation strategies of catalyst structure and electrode structure are summarized from four aspects: size effect, surface characteristics, defect engineering and multi-stage structure, and the development of electrocatalytic carbon dioxide reduction is prospected.

In the processes of uranium mining and nuclear power utilization, water pollution caused by radioactive contaminants (e.g., uranium) is becoming increasingly serious. Nanoscale zero-valent iron (nZVI) and its composites can be used to enrich low-concentrated uranium ions from radioactive wastewater effectively. Published works have demonstrated that nZVI has great application potential to treat uranium-contanined radioactive wastewater. However, published researches on the performance and mechanisms for U(VI) immobilization by nZVI between different papers are not unanimous. Based on the research progress, this review summarizes the aqueous and solid reaction mechanisms (e.g., adsorption, reduction and precipitation) between nZVI and U(VI) ions, and specifically discusses the effects of solution factors (e.g., pH, U(VI) concentration, cations, anions and dissolved oxygen) on U(VI) immobilization. Before the field-scale application of nZVI to remedy uranium wastewater, deep researches should be conducted to investigate: (i) the phase transformation of nZVI in uranium wastewater and the synergistic effect of solution factors on the ability of nZVI to separate uranium; (ii) based on the characteristics of radioactive solution and wastewater treatment processes, the structure of nZVI particles needs to be optimized and their long-term stability and ecotoxicity needs to be evaluated; (iii) confirm the mathematical correlation between the performation of nZVI to immobilize uranium and wastewater components and operation parameters, and then extabilish the monitoring and regulating method for wastewater treatment technology.

Converting CO₂ into value-added compounds via photothermal catalysis is a promising strategy to reduce CO₂ emission and might be a sustainable alternative to traditional fossil fuels. Here, we report nano-structured a Pt_0.01Fe_0.05-g-C₃N₄ hybrid catalyst synthesized via hydrothermal-method and further reduced under reaction condition for the reverse water gas shift (RWGS) reaction. Taking advantage of the photo-thermal effect caused by the near-infrared (NIR) and visible light responsive, the hybrid catalyst produces a remarkable activity (7.36 mmol•h^-1•g_cat^-1) for CO₂ reduction with CO selectivity (97%) under 300 W Xe lamp irradiation and CO₂/H₂ (V/V, 1/1) feed gas. The apparent activation energy of reaction decreases from 238.59 kJ/mol to 48.88 kJ/mol calculated by Arrhenius formula. In order to comprehend the good catalytic activity of Pt_0.01Fe_0.05-g-C₃N₄in the RWGS reaction, the catalyst is characterized with powder X-ray diffraction (XRD), spherical-aberration-corrected scanning transmission electron microscopy (Cs-S/TEM) integrated with X-ray energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), UV-vis-NIR diffuse reflectance spectroscopy (DRS),etc. for investigating the structural information, surface state, optical properties and so on. Results show that the presence of FeO _x and Pt exhibits strong absorption in a wide range from UV to NIR regions. Low photoluminescence (PL) intensity at about 460 nm shows the suppressed photogenerated carrier recombination process of Pt_0.01Fe_0.05-g-C₃N₄ due to the heterojunction between FeO _x and g-C₃N₄. Operando diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) under different reaction conditions is employed to investigate surface species and their evolution during the conversion of CO₂ into CO and a broad IR absorption is observed due to hydrogen spillover from Pt to Fe₃O₄. Therefore, we propose a possible mechanism of photothermal catalytic CO₂ reduction, involving separate activation of CO₂ and H₂ over Fe and Pt acitve sites. Our work present a high-performance Pt_0.01Fe_0.05-g-C₃N₄ catalyst for RWGS reaction and open a new vista of the design, synthesis and mechanism research of photothermal catalytic CO₂ conversion in the future.

The biomedical applications of fluorescence/photoacoustic imaging and phototherapy have attracted more and more attention. However, many fluorescent/photoacoustic contrast agents have some common problems, such as poor biocompatibility, lack of tumor targeting, low signal-to-noise ratio, single function and so on, which seriously limit their application in diagnosis and treatment. Hyaluronic acid (HA) exhibits excellent biocompatibility and active tumor targeting, can be degraded by hyaluronidase, and is easy to be chemically modified and realize the cooperation of a variety of supramolecular weak interactions. Therefore, HA has been combined with fluorescent/photoacoustic contrast agents to prepare nanomaterials, which greatly improves the labeling performance and therapeutic effects in cells and even in vivo. In this paper, the preparation methods of nanomaterials by combining these two kinds of materials are reviewed, and the relationships between the structure and performance of nanomaterials are emphasized, which provides guidance for their future design and development. Finally, the main problems and important research directions in the future are analyzed and prospected.

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by memory loss, confusion, and a variety of cognitive disabilities. The self-assembly and aggregation of β-amyloid (Aβ) peptides is a main feature of the brain of Alzheimer's disease, which can aggravate the nerve damage and cognitive impairment of AD patients. Therefore, inhibition of the aggregation of Aβ peptides is recognized as a potential strategy to alleviate AD. Photodynamic therapy (PDT) is a creative method that has wide applications in suppressing amyloid aggregation or eliminating the amyloid aggregates. However, most photosensitizers are excited by ultraviolet and visible light, have a low penetration depth in biological tissues, and cause serious tissue damage, which limits their application in biomedicine. Herein, we report a dual-targeting upconversion nanoprobe excited by near-infrared light to inhibit the Aβ aggregation process. The core-shell structured upconversion nanoparticles NaYF₄:Yb,Er,Gd,Tm@NaYF₄ are used as light converters, and the photosensitizer chlorin-e6 (Ce6) is loaded through the hydrophobic coating of the amphiphilic polymer 1,2-distearoylsn-glycero-3-phosphoethanolamine-N- [maleimide(polyethyleneglycol)-2000] (DSPE-PEG-MAL). A blood-brain barrier targeting peptide, TGN, and a Aβ target peptide, QSH, are simultaneously modified on the surface of nanoparticles via the specific reaction between maleimide and sulfhydryl groups. The results indicate that UCNPs can transfer the excited-state energy to the photosensitizer Ce6 through luminescence resonance energy transfer (LRET) process under the excitation of near-infrared light irradiation. After transition to the excited state, Ce6 further interact with the surrounding oxygen molecules to produce singlet oxygen (¹O₂) and irreversibly oxidize β-amyloid, thus effectively disassembling Aβ aggregates and reducing the cytotoxicity associated with Aβ. In addition, UCNPs-Ce6-TQ not only exhibits good biocompatibility, but also can effectively cross the blood-brain barrier and target Aβ₄₂. This nanoprobe may be a powerful tool to inhibit the accumulation of Aβ in the brain and alleviate the neurotoxic damage caused by Aβ.

Diarylmethine structure units are widely present in natural products and pharmaceuticals with important physiological and pharmacological activities. The enantioselective control of its stereogenic center, which is the most unique in this structure unit, has often become a difficulty and challenge during the research of total synthesis of natural products. Therefore, this field has attracted great interest to many organometallic chemists and synthetic organic chemists. In recent years, the construction methods of this stereocenter developed rapidly, and new reactions and reagents have emerged one after another. Some highly efficient catalysts have been invented, exhibiting unique catalytic activity and selectivity. In this review, according to the difference of reaction types, these methods can be divided into six types, such as asymmetric conjugate addition reaction (asymmetric 1,4-addition reactions involving aryl boronic acids, asymmetric 1,4-addition reactions involving aryl borates, enantioselective organocatalytic 1,4-addition reactions, asymmetric 1,4-conjugate addition induced by Evans chiral imide and asymmetric 1,6-conjugate addition of para-quinone methides), asymmetric allylation or propargylation of aromatic rings, transition metal-catalyzed asymmetric cross-coupling reaction, transition metal-catalyzed asymmetric C―H bond activation and functionalization, three-component reactions for asymmetric synthesis of 1,1-diaryl alkanes, asymmetric hydrogenation reactions for 1,1-diaryl alkanes, etc. This review aims to collect and summarize the asymmetric construction methods of diarylmethine stereogenic centers, and their applications in the total synthesis of natural products in the past decade. Finally, from the perspective of total synthesis, we further summarize and analyze the future development trend for the construction of diarylmethine chiral stereogenic centers, and encourage young generation to develop new methods and reagents that can avoid use of precious metals/catalysts and therefore are more efficient and environmentally friendly. More importantly, we hope that the developments of these practical methodologies can be further applied to asymmetric total synthesis of natural products and medicines, and eventually solve the source problem of these “useful molecules” with potential medicinal value.

Neptunium (Np) and plutonium (Pu) are two important actinides in nuclear industry. They can be generated through neutron capture of uranium (U) in reactors or decay from other transuranic elements. Representative isotopes of Np and Pu such as ²³⁷Np and ²³⁹Pu have long half-lives and possess high radiotoxicity, therefore may impose great hazard to biological system if they are released into the environment. The rich redox chemistry of Np and Pu further adds complexity of their chemical behavior in the environment. The coordination chemistry of Np and Pu in aqueous solution is of great significance to help understand and control their speciation distribution and migration behaviors in aqua environment. This article reviews the advances in coordination chemistry of Np and Pu with several common inorganic anions (OH^–, $CO_3^{2-}$, $SO_4^{2-}$, Cl^–, $NO_3^-$, F^–, $PO_4^{3-}$) in aqueous solution, especially the speciation and coordination thermodynamics between Np/Pu in different oxidation states and these anions. In general, Np and Pu ions in the same oxidation state exhibit similar coordination behavior (species, structure, stability constants, etc.) when coordinating with the same anion. The coordination strength for Np/Pu ions in different oxidation states with the same anion ligand is roughly in the order of IV>III, VI>V. For the coordination of Np/Pu ions with different anions, the strength sequences are OH^–>F^–> ${H_2}PO_4^-$> $NO_3^-$>Cl^– for monovalent anions and $CO_3^{2-}$> $HPO_4^{2-}$> $SO_4^{2-}$ for divalent anions. Factors such as instability of Np/Pu ions in some oxidation states, weak complexation, and low solubility of the complexes in the aqueous solution cause difficulties in obtaining precise and reliable coordination parameters for these ions experimentally. Moreover, the coordination parameters determined by different methods may vary with each other. To obtain more reliable parameters for the coordination of Np/Pu ions with these anions in the future, the use of more advanced characterization methods and the assistance of theoretical computation may provide strong support.

Although enzyme catalysis has many advantages such as green, high efficiency and so on, the industrial application of enzyme is often hampered by a lack of long-term operational stability and difficult to re-use. These drawbacks can generally be overcome by immobilization of the enzyme on a solid carrier. However, the immobilized enzyme reactor often can not remain all the initial catalytic activity due to the enzyme shedding during reuse, change of conformation and the difficulty for substrates to access the active site of enzyme in the carrier, etc. The contradiction between catalytic activity and stability of biological enzyme molecules supported on solid phase carriers has become a bottleneck in the design and preparation of immobilized enzyme reactors. Therefore, it is a challenging task to construct an immobilized enzyme reactor with both high catalytic activity and high stability. In this work, aluminum-based metal-organic framework (Al-MOF)-derived hierarchical porous Al₂O₃ (MHAl₂O₃) was prepared by the self-sacrificial template strategy and functionally modified with “polydopamine (PDA)” bionic membrane for entrapping horseradate peroxidase (HRP). The pore size was regulated by changing the calcination temperature of precursor. The influence of channel confinement effect of the carrier on the catalytic activity of the enzyme reactor was discussed, and the thermal stability and reusability of the HRP@PDA@MHAl₂O₃ was significantly improved. After 1 h at 70 ℃, 98.5% of the catalytic activity of HRP@PDA@MHAl₂O₃ could be maintained. After 10 times of reuse, 90.9% of the catalytic activity was still maintained. In order to analyze the structure-activity relationship of the enzyme reactor, the interaction between enzyme and substrate in the reaction catalyzed by HRP@PDA@MHAl₂O₃ was studied by means of enzyme kinetics and thermodynamic parameters, which showed that the affinity and specificity of the enzyme to the substrate were improved. When the enzyme reactor was applied to the catalytic degradation of aniline aerofloat in simulated wastewater, the degradation rate of 40 mg•L^-1 substrate in 30 min reached 82.7% under the best reaction conditions.

Aryl alkyl ethers and diaryl ethers represent ubiquitous structural motifs in natural products, medicinally relevant compounds, biologically active compounds, agrochemicals and organic materials, and they are also useful building blocks in organic synthesis. Therefore, many transformations have been reported for the synthesis of these two kinds of compounds. Among these versatile methods, transition-metal-free approaches using different reagents as starting materials have been developed as promising and alternative protocols. Although one example for transition-metal-catalyzed transformation of arenesulfonates into aryl alkyl ethers and diaryl ethers has been reported, there are no reports about the formation of aryl ethers utilizing arenesulfonates as starting materials via a transition-metal-free protocol, and existing methods for providing sterically hindered ortho-substituted diaryl ethers using electrophiles substituted by electron-deficient groups, particularly by a bulky one at the ortho-position as starting materials are very rare. We will report a K₂CO₃-mediated method for the synthesis of aryl alkyl ethers using arenesulfonates as starting materials via two alternative paths. One path is the cross-coupling of aryl arenesulfonates with alcohols through their S―O bond cleavage, and the other uses the reactions of alkyl arenesulfonates with phenols via their C―O bond cleavage. Additionally, we also report the K₃PO₄-promoted preparation of bulky ortho-substituted diaryl ethers via the C―S bond cleavage of aryl arenesulfonates or arenesulfonyl chlorides bearing electron-withdrawing groups at 2-, 2,4- or 2,6-position of the phenyl ring in the presence of phenols, respectively. General procedure for the reactions of aryl arenesulfonates with various alcohols: to an oven-dried glass tube, aryl arenesulfonate 1 (0.2 mmol), K₂CO₃ (2 equiv.) and 0.5 mL alcohol 2 were added in turn. The reaction system was then stirred at 65 ℃ until the aryl arenesulfonate 1 was completely consumed as determined by thin layer chromatography. Finally, the reaction mixture was purified by silica gel column chromatography to afford the desired product 3. General procedure for the reactions of aryl o-substituted arenesulphonates with the corresponding phenols: to an oven-dried glass tube, aryl o-substituted arenesulfonate 7 (0.2 mmol), K₃PO₄ (3 equiv.), the corresponding phenol 5 (1.2 equiv.) and 1.0 mL toluene were added in turn. The reaction system was then stirred at 100 ℃ until the reaction was over as determined by TLC. Finally, the reaction mixture was purified by silica gel column chromatography to afford the desired product 8.

Macrocycles such as cyclodextrin and crown ether are applied to construct artificial transmembrane ion transport systems owing to their unique cavity structure and the ability to recognize molecules and ions via host-guest interaction. Compared with natural channel proteins, macrocycles have many advantages, such as the low cost, stabilities, easy structural modification and functionalization, etc., which make them preferable candidates for preparing artificial ion channel. Herein, we reviewed the recent progress of macrocycles-based artificial ion channels, and systematically summarized the preparation methods, structural regulation and potential applications of the artificial ion channels based on different macrocycles. Finally, we have briefly summarized and outlooked the progress of macrocycle-based artificial ion channels. This review is of great significance for developing novel artificial transmembrane ion channels and exploring their potential applications.