Thermoplastic polyurethane (TPU) elastomer is widely used in biomedical field because of its good processability, mechanical property and biocompatibility. Most TPUs are composed of macromolecular diols as soft segments, diisocyanate and chain extenders as hard segments, which provide the elasticity of the matrix and the framework rigidity of the chain network, respectively. The structural design of chain extender diol/ diamine and diisocyanate is the main method to construct functional TPUs. Researchers designed and prepared the functional monomers according to the specific clinical scene or usage requirements, and developed the corresponding medical TPUs. In this paper, the types and characteristics of macromolecular diols, diisocyanate and chain extenders are introduced. Their unique microphase separation structures are analyzed, and the relationship between the chemical/physical structure and the final performance is discussed. Then, the research progress and advanced applications of TPU in biomedicine at home and abroad are summarized. The applications of TPU as antibacterial, anticoagulant, hydrolytic and oxidation resistant, self-healing and degradable materials are emphasized. Finally, by summarizing and analyzing various standards of biomedical TPU and its device, the key problems of industrial application are put forward, and the future development direction of TPU is prospected.

In recent years, stimulus-responsive supramolecular gels, as a class of smart soft matter materials, have shown very promising applications in the fields of ion recognition materials, self-healing materials, biomaterials and drug release, and have attracted increasing attentions. Dendrimers and dendrons are highly branched macromolecules with well-defined molecular architecture and have been widely used as building blocks in the self-assembling of supramolecular gel-phase materials. The unique dendritic architectures make the dendritic molecules as ideal candidates to be modified with various different functional moieties to develop multiple functional soft materials, which ensure each functionality to work independently without interfering. This characteristic makes them show unique advantages in the construction of stimuli- responsive gels, especially multiple stimuli-responsive gels. The research progress of stimuli-responsive dendritic gels is summarized in detail from the aspects of dendritic gel design, gel-formation mechanism, response performance and response mechanism. Based on the different stimulus, the stimulus-responsive dendritic gels are classfied into the following categories: light-responsive dendritic gel, redox-responsive dendritic gel, ion-responsive dendritic gel, thixotropic-responsive dendritic gel and multiple-responsive dendritic gel. In addition, the current challenges and perspectives on stimulus-responsive dendritic gels are also discussed.

Besides the design and synthesis of nonfullerene acceptors, the selection of polymer donors is also critical in determining the photovoltaic performance of nonfullerene organic solar cells (OSCs). However, the selection criteria of polymer donors for nonfullerene OSCs has been rarely investigated. In this work, a novel nonfullerene acceptor (MDB) with sp³-hybridized-carbon-free ladder-type skeleton was developed and used as a model compound to study the effects of miscibility and molecular ordering in determining the performance of MDB-based solar cells. In order to achieve matched energy levels and complementary absorption, three wide-bandgap polymers (PM6, J71, and P3HT) with different chemical structures were selected to blend with MDB for OSCs. The donor:acceptor miscibilities of the three blends were estimated by contact angle measurements, while their crystallinity and phase separation were investigated by grazing incidence wide-angle X-ray scattering characterization and atomic force microscopy measurement, respectively. The interfacial tension values between MDB and PM6, MDB and J71, as well as MDB and P3HT were determined as 0.49, 0.16, and 2.00 mN•m^–1, in that order. Owing to the proper miscibility between MDB and PM6, the resulting blend film exhibits suitable phase separation, “face-on” molecular orientation as well as compact molecular π-π stacking, which promotes carrier transport and suppresses bimolecular recombination. As a result, the best-performance OSC based on PM6:MDB delivered an outstanding PCE of 13.26%. In contrast, J71:MDB-based devices exhibited a lower PCE of 8.16%, due to the excessively high miscibility of J71 and MDB. As for P3HT:MDB-based devices, the poor miscibility between P3HT and MDB provides the driving force for the formation of large phase separation, which leads to an extremely low PCE of 0.45%. This work demonstrates that suitable miscibility is one of the key factors to achieve high-performance OSCs, which is an important guideline for the design and selection of next-generation photovoltaic materials.

Cancer progression is often accompanied by a series of complicated variations of molecular pathology, varying enormously between individuals. Therefore, it is necessary to achieve precise diagnosis of tumor, especially at the molecular pathology level. In clinical trials, the traditional medical imaging can identify the position and the anatomical structure of tumors, but it is difficult to reveal their molecular pathology. Although the molecular details of tumors can be obtained later through the pathological analysis of biopsies, this approach is invasive and has spatiotemporal limitations. Unlike these strategies, the pathological biomarkers of tumors can be directly imaged in vivo through the probe-based molecular imaging technology, which aims to quantitatively study the real-time tumorous pathological features at a molecular level. This technology holds huge potentials in the clinical application of precise tumor diagnosis. In recent years, nanomaterials that possess superior optical or magnetic physicochemical properties have become one of the important signal carriers for constructing highly sensitive molecular imaging probes. In this review, the development of nanoprobe-based molecular imaging and the in vivo visualization of tumor molecular pathology are summarized. Specifically, the construction of the pathology responsive nanoprobes is highlighted. The current challenges and perspectives on the future steps needed to implement this nanotechnology in a clinical setting are also discussed.

Two-dimensional nanomaterials provide an ideal platform for the research of heat conduction in nanoscale, for their novel heat conduction properties derived from limited phonon transport. Due to unique two-dimensional expanded ultra-thin structure, interface engineering effectively induces the change of phonon vibration mode and the coupling of phonon vibration, leading to the differences of heat conduction behavior. Benefiting from wide adjustability of heat conduction properties, two-dimensional nanomaterials exhibit potential applications in the heat dissipation of micro-nano devices and thermal protection in harsh environments. This paper introduces the mechanisms and novel characteristics of heat conduction in classical two-dimensional nanomaterials in detail, expounds the influence of interface engineering on the heat conduction in two-dimensional nanomaterials, and further expects the prospects of atomic-molecular interface regulation in the field of heat conduction in two-dimensional materials.

Germanium monoselenide (GeSe) is a promising photovoltaic absorber material for thin-film solar cells due to its appropriate bandgap (about 1.14 eV), high absorption coefficient (>10⁵ cm^–1 at visible light), large carrier mobility (about 128.7 cm²•V^–1•s^–1) and benign defect properties arising from its antibonding states at the valence band maximum. The theoretical Shockley-Quiesser efficiency limit for GeSe single junction solar cells determined by its bandgap is above 30%. Moreover, this simple binary compound possesses earth-abundant, nontoxic constituents and high stability in ambient atmosphere. The easy sublimation feature of GeSe enables the deposition of high-quality films through an industrial close-space sublimation method. The fundamental properties of GeSe with emphasis on the material, optical, electrical, and defect properties are introduced, and then the recent progress of fabrication of GeSe thin films and solar cells is summarized. Finally, a brief perspective on the further development of GeSe thin-film solar cells is provided.

Photocatalytic water splitting to produce hydrogen is one of the most promising technologies to solve energy and environmental problems and realize the effective conversion and storage of solar energy. And the development of it has attracted more and more attention with the proposed target of peaking carbon dioxide emissions before 2030 and achieving carbon neutrality before 2060. After decades of unremitting efforts, this “Holy Grail” reaction has made many important research progresses. This article will review the basic concepts, activity test methods and precautions, types of photocatalytic reactions and means of measurement for efficiency. The development of photocatalytic materials including inorganic semiconductor including oxide, (oxy)nitride, sulfur oxides, oxyhalide, sulfide and solid solutions, sensitized photocatalytic materials, polymer, metal-organic framework materials, etc. are introduced. The important research progresses from the perspective of basic processes and key scientific issues such as light absorption, photo-generated charge separation and surface catalytic reaction of photocatalytic water splitting to produce hydrogen are summarized. The strategies for improving the charge separation such as construction of heterojunction, and the reduction/oxidation cocatalyst for promoting the surface catalysis are introduced. The research progress of hydrogen production by photocatalytic overall water splitting (OWS) using one-step or two-steps photo-excitation system is also summarized in details. For the one-step system, the different materials and the strategies of realizing OWS are introduced. Moreover, for two-step system, the types of electron transfer medium, the exploration of materials and the inhibition of competing reaction are mainly discussed. Finally, the challenges and potential development directions of photocatalytic water splitting to produce hydrogen are analyzed and prospected. It is hoped that through the brief introduction of this review, young scientific and technical personnel who have just been engaged in this research will have a clear understanding of some basic concepts, operating specifications, research progresses and current status in the field of photocatalytic water splitting.

Protein-protein interactions are involved in the regulation of many biological processes in cells, and the mapping of protein-protein interaction networks is crucial for understanding complex biological processes. Liquid chromatography-mass spectrometry (LC-MS) can identify and quantify thousands of proteins simultaneously in complex organisms with its high sensitivity and accuracy. Therefore, after the enrichment, labeling or co-fractionation of target proteins, combined with LC-MS technology to identify proteins accurately and sensitively, such techniques have been widely used in the analysis of protein-protein interaction networks in the complex samples. There are LC-MS-based methods for studying protein-protein interactions, including affinity purification mass spectrometry (AP-MS), proximity-dependent biotinylation coupled to mass spectrometry (PDB-MS), chemical cross-linking with mass spectrometry (XL-MS) and co-fractionation mass spectrometry (CF-MS). This review discusses the mechanism, advantages and applications of these methods for the identification towards the protein-protein interactions in cells.

The conversion of carbon dioxide has become a hot topic in the world today. Here, we adopt the strategy of in-situ electrochemical transformation to reduce layered bismuth oxide formate nanoflowers (BiOCOOH NFs) self-assembled with nanosheets synthesized by simple solvothermal method to porous bismuth nanoflowers (p-Bi NFs) with a large number of lattice dislocations. Specifically, 1.0 g Bi(NO₃)₃•5H₂O was ultrasonically dissolved in 10 mL N,N-dimethylformamide (DMF), then 70 mL deionized water was added to the above solution, and the resulting solution was ultrasonicated for 10 min at room temperature to ensure that all reagents were uniformly dispersed. The resulting solution was then transferred to a 100 mL Teflon-lined stainless steel autoclave, kept at 120 ℃ for 20 h, and then naturally cooled to room temperature. The results show that the minimum overpotential of the electrochemical reduction of carbon dioxide to formate is 436 mV. When the catalyst loading is 0.5 mg/cm², the partial current density of formate (j_formate) is as high as 24.4 mA•cm^-2, which is 5.5 times that of commercial bismuth (Commercial Bi); and the Faraday efficiency (FE_formate) of formate is 96.7% at –1.8 V versus saturated calomel electrode (vs. SCE). The FE_formate is over 90% in a wide potential window of over 500 mV. Moreover, the p-Bi NFs electrocatalyst is stable in formate production for more than 10 h in CO₂-saturated 0.5 mol•L^-1 KHCO₃ electrolyte. Compared with the normalized electrochemical surface area (ECSA), it was found that the j_formate of p-Bi NFs was still about 4.5 times higher than that of Commercial Bi. The high catalytic performance of the catalyst can be attributed to the unique micro/nano hybrid structure derived from the lattice collapse and reconstruction of precursors, resulting in porous and rough surface and containing high density of active sites with lattice dislocations and defects. This study provides new insights into designing and synthesizing electrocatalysts with high performance for carbon dioxide reduction to formate.

Perhydropolysilazane (PHPS) derived silica materials have received extensive attention due to their potential applications in fields of memory chip and flexible display encapsulation. However, the current understanding of PHPS conversion process is not deepened yet, which is unfavorable to further research. To clarify PHPS conversion process, this work systematically studied conversion mechanism from PHPS to silica, and investigated the influence of chemical composition and microstructure on volume shrinkage, refractive index and mechanical properties in the conversion process. The coating samples were prepared by hydrolysis and condensation reaction of PHPS under conversion condition of heat. Chemical composition and microstructure of the obtained samples were analyzed by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, energy dispersive spectrometer and peak table mode of atomic force microscope. It is found that, when the conversion temperature is below 180 ℃, the conversion of PHPS is dominated by the hydrolysis and condensation reaction of Si—H and Si—N bonds, and its conversion degree is low. The formed samples show sea-island structure, which is composed of a dispersed silica phase and continuous PHPS phase. When the conversion temperature is in the range of 180~300 ℃, the transformation depends on oxidation reaction. It results in growth of silica phase, formation of bi-continuous phase, phase reverse between PHPS and silica phase with the temperature above 200 ℃, and formation of continuous silica phase. When the conversion temperature is in the range of 300~600 ℃, the silica network is basically formed, and it is densified by further treatment at higher temperature. The volume shrinkage, refractive index, and mechanical properties of PHPS converted samples depend on the conversion degree and phases’ distribution.

¹³⁷Cs has the strong radioactivity and long half-life. In the event of leaking, it will pose a great danger to human health and the environment. The effective removal of ¹³⁷Cs⁺ from complex radioactive waste streams remains a challenge due to its high solubility, easy migration and the influence of interfering ions in the waste streams. In this study, two new three-dimensional microporous lanthanide metal-organic framework compounds (Me₂NH₂)_0.5(H₃O)_0.25Na_0.25Ln(OH)(stp)• 0.25H₂O (FJSM-LnMOF; Ln=Eu, Tb; H₃stp=2-sulfonic acid terephthalic acid) are synthesized by the solvothermal method, which have the good water stability and acid-base resistance. The adsorption performance of FJSM-LnMOFs for Cs⁺ are tested with solid-liquid ratio of 1∶1 under stirring at room temperature for 8 h. The adsorption kinetics of FJSM-EuMOF for Cs⁺ are tested with low-concentration Cs⁺ solution. FJSM-LnMOFs show fast kinetics and high adsorption capacities of Cs⁺ ions (the maximum adsorption capacities q_m^Cs of FJSM-EuMOF and FJSM-TbMOF are 229.25 and 211.28 mg/g, respectively). They have good selectivity for Cs⁺ ions (K_d^Cs value up to 2.18×10³ mL/g). Even in the presence of interfering Na⁺, K⁺, Mg²⁺, Ca²⁺ ions, they still show selective adsorption performance for Cs⁺ ions. Impressively, we successfully obtain the single crystal structure of Cs⁺-absorbed product by soaking FJSM-EuMOF crystals in 20,000 mg/L Cs⁺ solution, which confirms that the adsorption mechanism of Cs⁺ ions is ion exchange by the means of single crystal structure analysis combined with various characterization methods including X-ray photoelectron spectroscopy (XPS), infrared spectroscopy (IR), energy dispersion spectrum (EDS), elemental analysis (EA). The results indicate that the highly efficient Cs⁺ adsorption of FJSM-LnMOF mainly originates from the strong interactions between COO^– and $\text{SO}_{3}^{}$ functional groups from organic ligands and Cs⁺ ions, and the presence of easily exchangeable [Me₂NH₂]⁺ cations and [H₃O]⁺ located in the channels. This work indicates the potential application of lanthanide metal-organic frameworks in the remediation of radioactive cesium.

Due to their low density in atmosphere, theoretical simulations of the nucleation of gas-phase molecules are computationally very expensive. In this study, neural network potential (NNP) is combined with enhanced sampling techniques to effectively investigate the nucleation of water clusters in gas phase. The neural network potential is trained based on water-cluster energies and forces from density functional theory (DFT). The problem that the binding between water molecules is too weak in the previous empirical force field model has been solved in the NNP. This NNP potential is then applied to Monte Carlo simulations in grand canonical ensemble with enhanced sampling methods such as aggregation-volume-bias Monte Carlo (AVBMC) and transition-matrix Monte Carlo (TMMC) to realize a random walk among different cluster sizes. Probability distribution of water cluster sizes and the corresponding Gibbs free energies can then be obtained. Subsequently, the evaporation rates of water clusters can be calculated via umbrella sampling Monte Carlo simulations in canonical ensemble combined with variational transition state theory (VTST). We observe a big change of free energy and evaporation rate from tetramer to pentamer. A statistical analysis of the number of hydrogen bonds suggests that more hydrogen bonds are required to be broken in the evaporation reaction of tetramer compared to that of trimer and pentamer. Structure analysis indicates that, although the ground state of the pentamer has a two-dimensional ring structure, three-dimensional hydrogen bond network begins to form in pentamer at finite temperature. Therefore, it is a two-dimensional to three-dimensional transition from tetramer to pentamer. The fact that the most probable configuration of pentamer is different from the lowest energy configuration demonstrates the importance of molecular simulations. Simply finding the lowest energy configuration via global geometry optimization and then calculating the free energy within a harmonic approximation of vibrations are not a universal protocol for cluster systems. Methods used in this study are expected to be applicable for more complicated multicomponent systems, which opens an avenue for the research of particulate matter formation in atmosphere.

The sensitive and specific detection of key molecules and biological micro/nanoparticles in complex biological systems is of great significance for understanding biological processes at multiple levels and scales, uncovering the mechanisms of disease onset and development, and exploring novel biomarkers. Microfluidic biosensors with advantages of microfluidics and biosensing have made significant progress in the precise detection of biological samples with small volumes. Recent years, thermomicrofluidic biosensing that combines thermophoretic migration in a temperature gradient and homogenous signal amplification strategies has realized rapid, sensitive, in situ detection of biomolecules and biological micro/ nanoparticles in complex biological systems. Different thermomicrofluidic biosensing strategies, including microscale thermophoresis (MST), thermophoresis-convection coupling, thermophoresis-diffusiophoresis coupling, and thermophoresis-electrophoresis coupling were presented. The fundamentals, features, and applications of these strategies in detecting biomolecules (protein, nucleic acids, etc.) and biological micro/nanoparticles (extracellular vesicles, viral particles, cells, etc.) were summarized. The challenge and future directions for the application of thermomicrofluidic sensing in biomedical detection were discussed.

AgInSe₂ (AISe) quantum dots (QDs) exhibit large Stokes shift, composition-dependent photoluminescence (PL), long PL lifetimes and low toxicity, making them exceptional candidates in a wide variety of bioapplications. However, it remains notoriously challenging to precisely control both the morphology and composition to optimize the PL performance of AISe QDs via conventional direct synthesis. Herein, we develop the unique low-temperature (75 ℃) template-based synthesis of highly efficient near-infrared (NIR) luminescent AISe QDs from In₂Se₃ QDs via a facile cation exchange method. The brief synthesis AISe QDs process was as follows: firstly, indium acetate was dissolved in non-coordinating solvent octadecene. Selenium precursor was injected into the above mixture at 200 ℃, followed by nucleation and growth within a few minutes. Thereafter, In₂Se₃ template QDs can be acquired, and the dispersity of the as-prepared QDs can be improved by adding zinc. Secondly, silver acetate was added to the In₂Se₃:Zn²⁺ QDs solution with stirring for 15 min at 75 ℃. Finally, AgInSe₂:Zn²⁺ QDs were obtained. The proposed method enables the as-prepared AISe QDs to inherit the size and morphology of the template QDs. The extent of cation exchange can be controlled by rationally manipulating the Ag/In precursor molar ratio. We successfully regulate the stoichiometry of Ag/In ratio from 0.26 to 1.09. As a result, highly efficient luminescence of AISe QDs with the maximum absolute quantum yield of 42.5% has been achieved, which is higher than that of the AISe counterparts synthesized via the direct method. Moreover, we survey the luminescence mechanism of AISe QDs by means of the steady-state, transient and temperature-dependent spectroscopies. AISe nanoprobes were prepared by coating the hydrophobic QDs with a layer of 1,2-distearoyl-sn-glycero-3-phosphoethanol-amine-N-[biotin(polyethyleneglycol)- 2000] (DSPE-PEG-Biotin) phospholipids through hydrophobic interaction. By virtue of the excellent biocompatibility and intense NIR emission, we exemplify the application of AISe nanoprobes in the targeted cancer cell imaging, thus revealing their promising bioapplications including disease diagnosis and imaging-guided surgery.

Nowadays, nanotechnology has been widely used in many fields such as medicine, catalysis, food and agriculture. With the rapid growth of the production amounts of anthropogenic nanoparticles (NPs), they will inevitably enter the natural environment after use and disposal. As a result, their potential risks to the environment and human health have caused significant concerns. Tracing the sources and environmental transformation of NPs is the prerequisite for the accurate evaluation of toxicity effects and pollution control. The recent progress in the area of source tracing technologies for NPs, including multi- chemical fingerprinting technology, non-traditional stable isotope tracing technology, isotope labeling technology, and DNA labeling technology is outlined. Furthermore, the future development of tracing technologies of NPs is also prospected.

Solution small-angle scattering (SAS) is a powerful tool for elucidating the structural properties of soft matter systems. SAS includes X-ray scattering (SAXS) and Neutron scattering (SANS) techniques which allow determination of the material’s properties at a scale ranging from few Angstroms to hundreds of nanometers. Wide time scales ranging from real time (milliseconds) to several minutes can be also covered by these techniques. In recent years, solution SAS techniques have had versatile applications in several research fields, especially in structural biology and in probing self-assembling nanomaterials. Probing the structure of materials at micro- and nano-scales provide an insight on the macroscopic properties of the material. The high throughput and fast time resolution offered by SAXS in combination with the neutron penetrating ability in SANS can offer a great potential to cover different soft-matter systems and processes (i.e. probing the kinetic of self-assembly). Here we review the solution SAS (both synchrotrons and Neutron Sources) capabilities which have been established in mainland China, and cover scattering theoretical developments. Recent advances in solutions SAS used in soft matter will also be discussed. Given the potential offered by the next generation X-ray and Neutron sources, further developments in this field are expected, with a proliferation of solution SAS applications.

Organic solar cells (OSCs) are among the most promising photovoltaic technologies to solve energy and environmental problems. To achieve highly efficient OSCs, controlling over electrode interfacial layers is greatly important for improving charge transportation and collection. Here, ternary metal oxide semiconductor films of Mg-doped NiO (NiMgO) have been prepared via a sol-gel method, and further optimized by several post-treatment strategies. The structures, properties and energy levels of different NiMgO films have been investigated to explore the influence of various post-treatment strategies. Incorporating the ternary NiMgO films as a novel type of hole transport layers (HTLs), non-fullerene OSCs have been fabricated based on a promising bulk-heterojunction of PM6:M36. Their photovoltaic performances and mechanisms of device physics are also investigated. When the sol-gel derived NiMgO film without post-treatment is used as an HTL, the OSCs show a relatively low power conversion efficiency (PCE) of 5.90%. By contrast, after simple ultraviolet-ozone (UVO) post-treatment on the NiMgO HTL, the resulted OSCs exhibit greatly enhanced photovoltaic performances, with an increased open-circuit voltage (V_OC) of 0.87 V and an improved PCE of 12.67%. More importantly, a new dual post-treatment combining surface rinse with UVO treatment has been demonstrated to further optimize NiMgO HTLs and improve device performances. The rinse process can remove excess impurities and flatten the surface of NiMgO films as well as increase the transmittance, while the UVO treatment process is beneficial for reducing surface defects of the ternary oxide films. Benefit-ing from such an efficient dual post-treatment on NiMgO HTLs, the OSCs afford a high PCE of 13.17% with a retained V_OC of 0.87 V, an increased short-circuit current density of 23.48 mA•cm^–2, and an improved fill factor of 64.29%. These results provide an effective way for surface post-treatment and property optimization of semiconducting metal oxide films, and contribute to the development of high-performance optoelectronic devices.

HMOR zeolites has an excellent performance similar to enzyme catalysis in the carbonylation of dimethyl ether (DME). The distribution of framework aluminum and the identification of the active site of the reaction are the key issues in the study of the reaction mechanism. The early work was based on theoretical calculation to study the active site of DME carbonylation, but lacked direct experimental evidence. In this work, a series of HMOR catalysts were prepared by calcination of NH₄MOR at various temperatures. The stability and location of framework aluminum were studied by a variety of spectroscopic characterization methods. Moreover, the evidence of reaction mechanism was obtained by the carbonylation reaction activity of dimethyl ether related to the acidity of MOR zeolite and aluminum distribution. Firstly, it was found that the crystallinity and morphology of MOR zeolites did not change significantly after calcination at different temperatures by XRD (X-Ray diffraction) and SEM (Scanning electron microscope). However, it was found by ²⁹Si, ²⁷Al and ¹H Magic angle spinning (MAS) solid-state nuclear magnetic resonance (NMR) that the local environment of HMORs was dealuminated, which resulted in obvious defect hydroxyl groups and the decrease of Brönsted acid sites (BASs) content. In addition, the calcination temperature has a great influence on the stability of framework Al of HMORs. Increase of calcination temperature will accelerate the occurrence of dealumination. Quantitative ¹H MAS NMR combined with Fourier transform infrared spectra (FTIR) provided the distribution of BASs content in different channels of HMOR zeolites. By using 2D ²⁷Al multiple quantum (MQ) MAS NMR method combined with the representative slices parallel to the F2 dimension of MQMAS NMR spectra at selected F1 chemical shift to distinguish the framework Al sites, it was found that when the temperature was lower than 600 ℃, framework Al atoms located in the different T-sites had the similar dealumination rate. But when the calcination temperature was increased to 600 ℃, the removal rate of Al atom at T3 site was accelerated. Furthermore, the relationship between the carbonylation performance of dimethyl ether and the distribution of Brønsted acid and aluminum was studied, and the definitive spectral evidence of the carbonylation activity center was obtained, that is, the Al site at T3-O33 was the active site of the carbonylation reaction.

Near-infrared (NIR) spectroscopy technique plays an important role in night-vision surveillance, food analysis, bioimaging and agriculture fields, and the development of compact and efficient NIR light source is a precondition for their massive commercial applications. Phosphor-converted light emitting diodes (pc-LED) have the advantages of compactness, low-cost, and long operating lifetime, thus have attracted considerable attentions in recent years. The key point is to exploit high performance NIR phosphors which can be excited efficiently by blue diode chips. A number of Cr³⁺-activated phosphors have been investigated aiming at NIR pc-LED applications. Nevertheless, most of the NIR phosphors show relatively short peak wavelength and narrow full width at half maximum (FWHM), resulting in spectral deficiency in the range 900~1100 nm. The phosphors with ultrabroad bandwidth are more desirable for spectroscopic applications. In this work, a novel broadband NIR light emitting phosphor In₂BP₃O₁₂:Cr³⁺ is synthesized by solid state reaction method. The structure, concentration and temperature dependent luminescence properties, electron-phonon coupling as well as the NIR LED performances and applications of the In₂BP₃O₁₂:Cr³⁺ have been investigated. Upon 480 nm excitation, the In₂BP₃O₁₂:Cr³⁺ phosphor shows a broad emission band peaked at 950 nm and covering 750~1350 nm (bandwidth of ~210 nm), which is owing to the ⁴T₂ → ⁴A₂ transition of Cr³⁺ ions. It is found that the emission intensity of the phosphor at 373 K keep 40% of that at room temperature. A NIR pc-LED is packaged by combining the In₂BP₃O₁₂:Cr³⁺ phosphor and a commercial blue InGaN chip, which generates broad NIR light emissions with an output power of ~5 mW at 60 mA drive current. When this NIR pc-LED is used to illuminate the human palm, the blood vessels in the palm are clearly imaged by a NIR charge coupled device (CCD) camera. These results suggest that the In₂BP₃O₁₂:Cr³⁺ is a promising phosphor for fabricating NIR pc-LEDs, which are potential for non-destructive analysis in the fields of biology and medicine.

Compared with traditional fluorescent biological imaging, the second near-infrared (NIR-II) fluorescent biological imaging technology has the advantages of high spatial resolution, excellent signal-to-background ratio, large imaging depth, low autofluorescence, and less biological damage, which is widely used in disease diagnosis, non-invasive treatment and other fields. Among diverse NIR-II fluorescent nanomaterials, NIR-II emitting lanthanide based nanoprobes (NIR-II Ln-NPs) have received extensive attention owing to their exceptional merits like good photochemical-stability, narrow emission band, tunable emission colors and long-lived lifetime. In this review, we provide a comprehensive survey of the latest advances in developing lanthanide-based NIR-II emitting nanoprobes as deep-tissue-penetration fluorescent diagnostic and therapeutic agents, which cover from their design strategy, controllable synthesis, surface functionalization, optical properties as well as their biomedical applications, with an emphasis on heterogeneous and homogeneous in-vitro biodetection of tumor markers and multimodal bioimaging of various tumor tissues. Some future prospects and challenges in this rapidly growing field are finally summarized.

Icosahedral carboranes are carbon-boron molecular clusters, sharing many features with benzene such as aromaticity, high thermal and chemical stability. On the other hand, carboranes have their own unique characteristics like spherical geometry and three-dimensional electronic delocalization. These properties render carboranes unique building blocks for various applications ranging from versatile ligands to functional materials to medicine. In this regard, functionalization of carboranes, particularly regioselective functionalization of cage B-vertexes has recently received much attention. Based on our recently developed Pd-catalyzed iodine-migration on o-carborane cage, a Pd-catalyzed regioselective difunctionalization of 3-iodo-o-carborane in a one-pot manner has been achieved to afford a series of 3-alkenyl-4-Nu-o-carboranes (Nu=arylamino, alkoxyl, alkyl and arylthio) in 47%~99% yields. This protocol combines the sequential activation of cage B(3)—I and B(4)—H bonds by Pd migration, as well as further Pd-catalyzed transformation of B(4)—I bond, leading to the construction of B—C and B—Heteroatom bonds. A general procedure for the synthesis of 3-alkenyl-4-Nu-o-carboranes is described as follows: to a tetrahydrofuran (THF) solution (1 mL) of NuH (1.0 mmol) was added base (1.0 mmol) at 0 ℃ under an atmosphere of dry nitrogen. The reaction mixture was stirred for another 10 min to obtain the NuM solution (NuM=ArNHMgBr, base=EtMgBr; NuM=Ar₂NLi, base=ⁿBuLi). Another oven-dried Schlenk flask equipped with a stir bar was charged with 3-iodo-o-carborane (1, 27 mg, 0.1 mmol), Pd(PPh₃)₄ (12 mg, 0.01 mmol), diphenylacetylene (89 mg, 0.5 mmol) and dry toluene (1 mL) under an atmosphere of dry nitrogen. The flask was closed, and stirred at 80 ℃ for 72 h. Then, the resulting solution was cooled to 0 ℃, to which was slowly added NuM (0.15 mmol) (NuM=ArNHMgBr, Ar₂NLi, ^tBuONa and RSNa). The reaction mixture was warmed to room temperature, and stirred at 80 ℃ for 24 h. After quenching with water (1 mL) and extraction with ethyl acetate (5 mL×3), the organic portions were combined and concentrated to dryness in vacuo. The residue was subjected to flash column chromatography on silica gel (300~400 mesh) using n-hexane as eluent to give the product.

Selective hydrogenation of quinoline toward 1,2,3,4-tetrahydroquinoline shows great application potential in the production of medicine, pesticides and fine chemicals. However, the hydrogenation of quinoline is usually carried out under harsh reaction conditions such as high temperature and high pressure, and thus, it is a great challenge to achieve selective hydrogenation of quinoline under mild conditions. In this work, we construct platinum nanoparticles (Pt NPs) sandwiched in an inner core and an outer shell composed of a metal-organic framework synthesized by zirconium chloride and 2,2'-bipyridine-5,5'-dicarboxylic acid (known as UiO-67N). Different sandwich structures with shell thickness of 11, 28 and 42 nm are precisely prepared. The obtained catalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), inductively coupled plasma emission spectrometer (ICP-OES), Fourier transform infrared spectroscopy (FTIR) and nitrogen adsorption and desorption. Impressively, the selective hydrogenation of quinoline over Pt NPs is significantly enhanced by using UiO-67N as support in respect with UiO-67. Moreover, UiO-67N@Pt@UiO-67N exhibits the selective hydrogenation of quinoline with high conversion rate (>99%) and high selectivity of 1,2,3,4-tetrahydroisoquinoline (>99%) at room temperature. The shell thickness has significant influence on the catalytic activity of Pt NPs, and with increasing the shell thickness from 11 to 42 nm, the conversion rate decreases from 99% to 53.5% under the identical conditions, while the selectivity of 1,2,3,4-tetrahydroisoquinoline is well kept. When other derivatives of quinoline are used as substrates, the excellent activity and selectivity are also achieved over sandwich catalysts. Besides, the UiO-67N@Pt@UiO-67N catalyst could be used at least 5 times without obvious deactivation, but the significant deactivation happens over supported UiO-67N@Pt catalyst. XPS and FTIR measurements show that the excellent catalytic performance mainly originates from the electron transfer between UiO-67N and Pt NPs, and the strong interfacial interaction between UiO-67N and quinoline.

Ion-molecule reaction is one of the most fundamental processes in the Earth and other planets' atmosphere, interstellar space and combustion. Basic physical chemistry processes such as charge transfer and energy transfer are frequently involved in the low-energy (several eV) ion-molecule reactions. In recent decades, the experimental study of low-energy ion-molecule reaction dynamics is highly benefit from the introduction of velocity map imaging method, but some dynamics mechanisms remain to be validated. Based on our own cross-beam ion velocity imaging apparatus, we have recently realized an efficient measurement of three-dimensional ion velocity images for multiple products by using a delay line anode detector, indicating the much higher efficiency. Upon above technique improvement, more details about the charge transfer reactions between Ar⁺ and small molecules have been revealed. Here we summarize and emphasize the dynamics differences among this process, photoionization and Marcus theoretical model. Meanwhile, we obtained stereodynamic characteristics of the dissociative charge transfer reactions of Ar⁺ with O₂ and CO. Moreover, comparison between the charge transfer only and dissociative charge transfer reaction indicates that the latter is not a subsequent even of the former, namely, these two processes may have completely different pathways. We also present a perspective about the experimental techniques those are potentially applicable and some interesting topics in the future.

Drugs can be roughly divided into small molecule drugs (naturally extracted or chemically synthesized) and macromolecular drugs (biologics) according to molecular weight. Although small molecule drugs are still the mainstay of drug research and development (R&D) at present, the slow update rate of small molecule libraries has retained their R&D speed, thus highlighting the increasingly important position of macromolecular drugs in the future pharmaceutical market. In addition to macromolecular biologics, chemically synthesized macromolecular drugs prepared by combining small molecule drugs with natural or synthetic macromolecules have received more and more attention in recent years. Due to the unique characteristic of abundant backbone architectures and spatial framework of macromolecules, including their distinctive backbone effect and multivalent effect, as well as aggregation effect and targeting effect produced by molecular assembly, many new possibilities will be introduced into the design of medicinal chemistry. In view of this, this review will briefly introduce macromolecular effects in medicinal chemistry design, with an emphasis on new performances and functions introduced in drug design based on the backbone effects, multivalent effects, aggregation effects, and targeting effects of synthetic macromolecules. We hope this review could promote the development of chemically synthesized macromolecular drugs and provide new horizons for medicinal chemistry design.

Jarosite is a common iron-containing mineral. Researchers have studied its application for removing aqueous pollutants, such as Cr(VI) and As(V). Surprisingly, it shows adsorption for arsenates, but little for the structurally similar phosphate ions. In this study, we prepare cerium doped jarosite and prove the successful doping of cerium at the K⁺ site by X-ray diffraction (XRD), inductively coupled plasma-optical emission spectrometry (ICP-OES), energy dispersive spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS). Phosphorus adsorption experiments show that the small amount of cerium doping (Ce content: 8.75×10^-5 mol/g) significantly improves the phosphate adsorption of jarosite, from 1.69 mg/g to 29.33 mg/g (pH=7, 24 h). The phosphate adsorption of Ce-doped jarosite exhibits good pH stability (from pH=3 to pH=11) and excellent selectivity, which is capable of maintaining more than 91% of its adsorption capacity in the presence of various competing anions, such as HCO₃^-, CO₃^2-, humic acid anion, SO₄^2-, NO₃^-, and SiO₃^2-. Further analysis reveals that the adsorption process obeys the pseudo-second order kinetic model while the adsorption isotherms represent the Freundlich isotherm. The analysis indicates that the adsorption may be a chemical adsorption process that is easy to proceed. To explore the mechanism of adsorption enhancement, we first characterize the Zeta-potential of the pure jarosite and Ce-doped jarosite. The result indicates similarity of the surface potential between the two samples, which rules out the electrostatic adsorption mechanism. Next, based on the result of anion exchange chromatography, we confirm that the cerium doping greatly increases the exchange between the sulfate groups in jarosite and the phosphate groups in solution, from 2.85 mg/g to 24.90 mg/g. Finally, XPS high-resolution spectroscopy reveals that the chemical environment of Ce changes after the phosphate adsorption, likely indicating the formation of Ce—O—P chemical bonds to achieve specific chemisorption. These results may provide insights for the modification and application of jarosite, as a new adsorbent material for treating phosphorus rich wastewater.

Light-responsive drug delivery systems (DDS) exhibit the advantages of non-invasive, high controllability and spatio-temporal precision. However, DDS triggered by near-infrared (NIR) light are few and inefficient. In this work, we designed a novel NIR-responsive upconversion nanoplatform for drug delivery. In this nanoplatform, core-shell upconversion nanoparticle (UCNP) NaYF₄:Yb,Er@NaYF₄ was coated by mesoporous silica, and then successively coupled with NIR dye cypate, amantadine (AD) and β-cyclodextrin (β-CD) to block the pores and entrap the drugs. The cypate molecules with the feature of auto-sensitized photooxidation under 808 nm irradiation were, for the first time, employed as light-responsive moieties in DDS. The obtained nanoplatform was characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), N₂ adsorption/desorption, dynamic light scattering (DLS) and zeta potential analysis. Mechanism of photocleavage of cypate by singlet oxygen (¹O₂) was also investigated by electron spin resonance (ESR) measurement. The nanoplatform loaded with antibiotic ofloxacin (OFL) showed a low drug leakage (6.9%) in the dark condition and a rapid release (50.9%) upon 808 nm irradiation with a relatively low power density of 0.5 W•cm^-2 for 40 min. Moreover, on-demand release of OFL can be achieved by adjusting the irradiation time (0~40 min). In vitro antibacterial experiments showed that the nanoplatform had a much better antibacterial effect against Staphylococcus aureus after 808 nm irradiation as compared with the group without irradiation. These results further verified the excellent NIR-responsive performance for the designed nanoplatform. In addition, the nanoplatform exhibited strong and stable upconversion luminescence (UCL) under 980 nm excitation, which can be applied for DDS tracing and bioimaging. The cytocompatibility of the nanoplatform was evaluated by methyl thiazolyl tetrazolium (MTT) assay, showing that the nanoplatform had no cytotoxic effect on human embryonic liver cell line (LO2) and exhibited great potentials in versatile bioapplications. Our work may open up a new avenue for the exploration of multi-functional NIR-responsive DDS.

During the past 170 years, organic small molecular fluorescent dyes had been widely applied in fluorescence labeling, fluorescence probes and bioimaging. And their structures and performances continually evolved with development of synthetic method and application. However, the emerging super-resolution imaging put forward higher requirements at brightness, stability and switching performance of organic small molecular fluorescent dyes, which also offers new opportunity for developing novel dyes at the same time. So, chemists presently pay more attentions on brightness and photostability. Twisted intramolecular charge transfer (TICT), the major nonradiative decay channel in organic small molecular fluorescent dyes, seriously decrease brightness and photostability. Therefore, inhibiting TICT has became the crucial strategy to develop organic small molecular fluorescent dyes towards super-resolution imaging. This review will firstly demonstrate mechanism and development of TICT and emphatically introduce the progress in improving organic small molecular fluorescent dyes based on inhibiting TICT.

Organogermanium compounds have been gaining more attention for their unique properties compared to silicon or tin. Among which, tetraalkylgermanes, especially alkyltrimethylgermanes that have been confirmed to be active in photoredox radical reactions, are still lack of efficient and simple synthesis methods. Herein, we report a new protocol using commercially available trimethylgermanium bromide and alkyl bromides as substrates and cheap copper(II) sulfate as catalyst. When using magnesium powder as the reductant, a series of alkyltrimethylgermanes could be generated in moderate to good yield. Mechanism studies suggested a probable in-situ Grignard reaction pathway. The copper salt added could significantly accelerate the reaction between organohalogermanes and Grignard reagents so that the formation of Ge-Ge byproduct from the reduction of organohalogermanes by magnesium could be inhibited. Compared to the traditional method using Grignard reagent and organohalogermanes, this new protocol has better compatibility towards functional groups like esters and amides. The protocol could also be expanded to the synthesis of various tetraalkylgermanes or germacycloalkanes using dichlorodimethylgermane and alkyl bromides. General procedure for the synthesis of alkyltrimethylgermane is: To an oven-dried 25 mL screw-capped tube equipped with a stir bar was charge with 48 mg (2 mmol) magnesium powder and 8.0 mg (0.05 mmol) CuSO₄. The tube was vacuumed and backfilled with argon for three cycles. 6 mL freshly distilled THF was added followed by the addition of 128 μL (1 mmol) trimethylgermanium bromide and 1.5 mmol alkyl bromide. The mixture was sealed with a Teflon stopper, warmed to 60 ℃ and stirred for 10 h. After cooled to room temperature, the resulted mixture was quenched with saturated NH₄Cl solution, extracted with diethyl ether and washed with brine. Combined organic layer was dried over Na₂SO₄ and concentrated under reduced pressure. The residue was purified by flash column chromatography on silica gel or distillation to give the desired alkyltrimethylgermane.

Dimethoxymethane (DMM) has wide application in resin, solvent, and fuel fields as a fundamental organic chemical. The traditional route to synthesize DMM using methanol and formaldehyde as reactants via condensation reaction has poor efficiency. Methyl nitrite (MN), which is obtained by the reaction of methanol, oxygen and nitrite monoxide without catalysts, could be used as raw material to produce DMM through catalytic decomposition. The current work systematically investigated the catalytic activity and selectivity to DMM of several molecular sieves in MN decomposition reaction. The results show that the activity trend is NaY (97%)=HY (97%)>HZSM-5 (90%)>Hβ (89%)>NaZSM-5 (18%)>Naβ (6%), and the DMM selectivity trend is NaY (53%)>HY (12%)=Naβ (12%)>NaZSM-5 (7%)>Hβ (4%)>HZSM-5 (3%). X-ray diffraction (XRD), Brunner-Emmet-Teller measurements (BET), scanning electron microscope (SEM) and Pyridine-IR (Py-IR) experiments have been employed to reveal the structure-activity relationship of these molecular sieves. Combining the temperature-programmed desorption of CO₂ experiments (CO₂-TPD) data with the evaluation results of the catalytic performance of the zeolite catalyst, the basic sites of the zeolite have no direct connection to the catalytic MN decomposition process. Meanwhile, the calcination temperature experiment of NH₄-zeolite and the catalytic performance test experiment of NaY-tetraethoxysilane (TEOS) further proved that the acid site played an essential role in promoting the decomposition of MN, and the results show that the Lewis acidity sites of Na⁺ and low-coordinated Al metal center are key factors to catalyze MN to DMM high selectively. We have proposed the MN decomposition mechanism. In the process of MN decomposition, there are both proton generation and proton consumption processes. Intermediates in the decomposition process are easily protonated by Brönsted acid sites to form by-products. The Lewis acid site of zeolite is generally a low-coordinated Al metal center, which can effectively adsorb and stabilize the oxygen-containing intermediates generated during the decomposition of MN, especially the methoxy and formaldehyde intermediates involved in the production of DMM, which is very beneficial to

the decomposition of MN to DMM. We believe that the research in this paper can provide a new and efficient synthetic route for DMM.

Polarized upconversion luminescence (UCL) of lanthanide (Ln³⁺)-doped micro/nano-crystals has shown great promise in areas such as single-particle tracking and biomedicine. The polarized UCL of Ln³⁺ ions is governed by their localized electronic structures and excited-state dynamics. In this work, β-NaYF₄:Yb³⁺/Er³⁺ microrods with controllable morphologies and sizes were synthesized through a solvothermal method. Based on the customized confocal laser microscopic system, the polarized UCL of a single β-NaYF₄:Yb³⁺/Er³⁺ microrod was systematically investigated. The emission polarization was probed by placing a half-wave plate coupled with a polarizer in front of the detector. As such, the polarized UCL spectra of a single NaYF₄:Yb³⁺/Er³⁺ microrod can be recorded by rotating the half-wave plate under 980-nm excitation. It was observed that the UCL intensity of the microrod exhibited a periodic variation with the emission polarization angle tuning from 0° to 360°, indicating polarization anisotropy of the microrod. Specifically, different crystal-field (CF) transition lines originating from two identical multiplets of Er³⁺ displayed drastically distinct polarization dependence. This results in a higher degree of polarization (DOP) of the UCL intensity for a certain CF transition of Er³⁺ in comparison with that of the integrated UCL intensity of the multiplet. Polar plots of the UCL intensities for the CF transitions of Er³⁺ as a function of polarization angle could provide a qualitative vision of the DOP, with a narrower “neck” indicative of a larger DOP. Moreover, the polar plots of a certain CF transition of Er³⁺ showed a consistent orientation with the corresponding NaYF₄:Yb³⁺/ Er³⁺ microrod and rotated with the rotating of the single microrod. Therefore, by utilizing the polar plots of the highly-polarized CF transition lines of Er³⁺, the spatial orientations of the microrod could be monitored, thus revealing the great potential of NaYF₄:Yb³⁺/Er³⁺ microrods as sensitive anisotropic UCL probes for single-particle tracking.

Infrared nonlinear (IR NLO) optical crystals have an essential position in military and civilian fields because of their ability to convert lasers from near infrared (NIR) to mid/far infrared (MIR/FIR). In this work, two alkali-metal chalcogenides, Rb₂MGe₃S₈ [M=Zn (1), Cd (2)], were successfully synthesized by high-temperature solid-state reactions. Both compounds feature a two-dimensional layered structure and have a large optical band-gap, the experimental band-gap of 1 and 2 are 3.24 eV and 3.16 eV, respectively. Compound 1 belongs to the centrosymmetric group P-1, while 2 belongs to the non-centrosymmetric space group P2(1)2(1)2(1) and exhibits obvious NLO effect, which is comparable to that of KH₂PO₄ (KDP) (@1064 nm) at the particle size of 50~75 μm. Particle-size dependent NLO response measurements indicated that 2 is non-phase-matchable. Compound 2 exhibits a high laser-induced damage threshold of 16.6×AGS at 1064 nm. Through the analysis of the crystal structures of these two compounds, the reason why their formulas have the same stoichiometric ratio but symmetries are different is the structure change of basic building unit [MGe₃S₈]^2– in 1 and 2. All M atoms in both compounds are coordinated by four S atoms to form MS₄ tetrahedra. In each [CdGe₃S₈]^2– unit of 2, three S atoms bonded to the Cd atom are also bonded to all Ge atoms in that unit, that is to say, each CdS₄ tetrahedron is connected to the other three GeS₄ tetrahedra by sharing S vertices. Unlike the coordination manner in the [CdGe₃S₈]^2– unit of 2, there are only two S atoms bonded to both Zn and Ge atoms in [ZnGe₃S₈]^2– unit of 1. This structure change of [MGe₃S₈]^2– unit eventually led to the non-centrosymmetric transformation. What’s more, to get insight into the origin of NLO effect of 2, theoretical calculations of electronic band structure and NLO susceptibility were performed based on density functional theory.

Sepsis is a life-threatening disease caused by a dysregulated host response to infection. Its pathogenesis is complex, and despite some advances in recent years, the mortality rate is still 25% to 30%. Sepsis treatment based on nanomaterials can be constructed for the purpose of eliminating infection sources and eliminating inflammation, which is an effective tool to fight sepsis. In this paper, the latest progress in the treatment of sepsis based on nanomaterials is reviewed. From the perspective of its pathogenesis, the nanomaterials for the treatment of sepsis based on antibacterial, scavenging of reactive oxygen species, and scavenging of dangerous molecules is reviewed in detail. And the problems and challenges facing the potential treatment in the future are discussed. The new challenges facing the treatment of sepsis using nanomaterials are also discussed in the hope to provide new ideas and solutions for sepsis treatment.

Metal-organic frameworks (MOFs) are one of the most important crystalline porous materials. In recent years, there has been a strong interest in MOFs based devices with electrochemical activity. MOFs with redox activity are the ideal choice for such devices. 1,1'-Ferrocene dicarboxylic acid (H₂FcDCA) containing ferrocene units is an ideal ligand for constructing MOFs with redox activity. However, due to its uncontrollable coordination mode and torsion angle, there is still a challenge to construct such materials. In this paper, two MOFs were synthesized by the reaction of functional ligand H₂FcDCA with Cd²⁺ under different hydrothermal conditions: [Cd(FcDCA)(bpy)(H₂O)]•(bpy) (1) (bpy=4,4'-bipyridine) and [Cd₂(FcDCA)(bpy)(OX)(H₂O)₂]•2H₂O (2) (H₂OX=oxalic acid). The single crystal structure, fluorescence properties, redox activity of two compounds were characterized and described. In compound 1, Cd center was linked by FcDCA to form a zigzag chain, and it was linked by bpy to form a chain. Both chains linked each other by sharing the Cd center to give birth to a 2D layer with square lattice topology (sql). These layers were packed in AA mode along ac plane. Bpy as guest molecules are filled in the channel of it. By introducing H₂OX in this system under similar condition, compound 2 with 3D framework was obtained. Different to compound 1, two Cd atoms were coordinated by OX ligands to form a binuclear Cd₂ unit. The Cd₂ units were connected by bpy and OX ligands to form a 3D framework with typical 4-connected diamond topology (dia). Each FcDCA ligand linked two Cd₂ units as functional unit and pore partition agent. The whole framework of compound 2 can be simplified as 6-connected sxd topology by treating three kinds of ligands FcDCA, bpy and OX as linkers. Both compounds exhibited strong visible light absorption ability, photocurrent response, and typical redox properties of ferrocene, which may be good candidates for photoelectric catalysts.

The development of modern automobile industry and the increasingly strict environmental protection regulations continuously drive the development of automobile lubricating oil. Friction modifiers play an important role in improving the friction reduction and fuel economy of the engine oil. Organic molybdenum compounds are the most widely used friction modifiers, the metal elements of which will increase the thermal oxidation deposits, and further affect the ternary catalytic converter system. Additionally, the friction reduction performance will decrease with the oxidation of oil. In view of the problems existing in friction modifiers such as harmful elements, ash content and limited active adsorption sites, two bis/triaza crown ethers were designed and synthesized in this paper. Active nitrogen atoms and long-chain alkyl groups were introduced into the structure of crown ether to provide adsorption sites and oil solubility. UMT-tribolab and 3D profilometer were applied to study the friction-reducing and anti-wear properties of the synthesized azacrown ethers under boundary lubrication regime. The adsorption properties of additive molecules on metal surface were analyzed by using steel surface contact angle measurement. And the composition of lubrication film on metal friction pair surface was analyzed by X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy, in order to clarify the lubrication mechanism of the azacrown ethers. The results show that both bis/triaza crown ethers can effectively reduce the friction coefficient and wear rate of base oil. The triaza-crown ether containing pyridine structure unit shows superior tribological properties, which can reduce the friction coefficient and wear rates by up to 8.8% and 42%, respectively. It can be indicated from the mechanism analysis that azacrown ethers can be adsorbed on the surface of steel in varying degrees. Under the shear stress of friction pairs, the compounds adsorbed on the surface further undergo tribochemical reaction to form lubricating protective film. The lubricant layer with ferric oxide and carbon film will prevent the sliding surface from direct contact to improve tribology performance.

Inorganic-organic hybrid perovskite-like materials have attracted widespread attention due to their tunable structure and unique optoelectronic properties. By simply changing the size of the organic cations, the structural dimensions of inorganic-organic hybrid perovskite-like materials can be adjusted. However, most of the research were carried out by selecting different types of organic cationic ligands, which is not conducive to the study of structure-activity relationship. Herein, by choosing different alkylation solvents, the control of dimensions and performance of inorganic-organic hybrid perovskite-like materials was realized when the reaction precursors were consistent. Two new inorganic-organic hybrid materials were synthesized in situ by a simple one-step hydrothermal method, that were two-dimensional (2D) [(Me₃)ODA(Me₃)]₃Pb₅I₁₆ (1) and one-dimensional (1D) [H(Et₂)ODA(Et₂)H]Pb₂I₆•H₂O (2) (ODA=4,4-diaminodiphenyl ether). Compound 1 is consisted by 2D inorganic perovskite-like network layers and [(Me₃)ODA(Me₃)]²⁺ organic dications, while compound 2 is composed by 1D inorganic perovskite-like chains, [H(Et₂)ODA(Et₂)H]²⁺ and water molecules. Compound 1 and 2 showed different structures and exhibited different stability, optoelectronics, and humidity sensitivity. The methylated compound 1 showed an obvious photoelectric response under visible light illumination (400~790 nm), and the ethylated compound 2 exhibited no photoelectric response. Compound 2 presented better stability to water and organic solvents compared to compound 1, which can be as an ideal candidate in fabricating smart and efficient sensors for humidity detection. The chemiresistive humidity sensor based on compound 2 showed an investigated response in the wide relative humidity (RH) (10%~100%) at room temperature. The sensor showed a high sensitivity in the range of 10%~100% RH and good cycle stability. It displayed 10⁵-fold increase toward 100% RH. The sensing mechanism of the compound 2 based humidity sensor was further studied by direct current (DC) instantaneous reverse polarity method, which proved that the moisture responsiveness was dominated by electronic conduction, and the free transmission of electrons dominated the change of material's conductivity.

Donor-acceptor cyclopropanes as efficient three-carbon synthetic building blocks were widely employed in the synthesis of many natural products and complex drug molecules. However, the ring-opening of aliphatic substituted cyclopropanes, owing to their poor reactivity, usually suffers from the harsh reaction conditions such as strong Lewis acid, large amount of catalyst, high reaction temperature and so on. In this paper, In(NTf₂)₃ was found as a powerful Lewis acid to catalyze the intramolecular nucleophilic ring-opening reaction of donor-acceptor cyclopropane with indole. This reaction could be used to construct the pyrrolo[1,2-a]-indole framework structure in a facile way. This method could be conducted in mild reaction conditions with a broad substrate scope (15 examples), leading to the target products in up to 96% yield. The general procedure is as following: To a dry Schlenk tube in a glove box, was placed In(NTf₂)₃ (0.1 equiv.), 4 Å molecular sieve (50 mg) and a stir bar. The tube was capped and brought out of the glovebox. After connected to argon via a typical Schlenk line system, a solution of 1 (1.0 equiv.) in PhCl (1 mL) was added dropwise until the reaction was completed (monitored by thin-layer chromatography). Et₃N was added to quench the reaction and the reaction mixture was filtered through a thin layer of silica gel and eluted with EtOAc (100 mL). After removal of the volatiles under reduced pressure, the residue was purified by flash chromatography over silica gel to afford the product. When indole substrate contains electron-withdrawing substituents, the reaction temperature needs to be increased to 100 ℃ to obtain the target product.

Low-dimensional semiconductors, especially recent emerging two-dimensional halide perovskites, have shown great potential in extensive optoelectronic applications due to their large structural anisotropy, unique quantum well effect and excellent semiconductor properties. Meanwhile, the bulk photovoltaic effect with a highly sensitive angle-resolved photoresponse arising from ferroelectric materials presents a promising approach for highly polarized-sensitive photodetection. Despite the blooming development of two-dimensional halide perovskite ferroelectric materials, it is a great challenge to grow bulk single crystals of two-dimensional halide perovskite ferroelectric, which restricts their further applications in polarized-sensitive optoelectronic devices. This work mainly focuses on the developing of low-dimensional halide perovskite ferroelectric crystals with excellent photoelectric response. Two-dimensional (2D) halide perovskite ferroelectric (iPA)₂EA₂Pb₃I₁₀ (iPA=isopentammonium, EA=ethylammonium) was synthesized by a solution method through the reaction of stoichiometric lead acetate, isoamine and ethylamine in concentrated aqueous hydroiodic acid. Meanwhile, high quality centimeter-size single crystals of ferroelectric (iPA)₂EA₂Pb₃I₁₀ with the max dimensions up to 15 mm×15 mm×3 mm have been grown via temperature cooling method. On the basis of grown bulk single crystals, further investigations on the crystal structure, optical properties measurements and electrical properties characterization were carried out. The photoelectric response performance and polarization photodetection performance of photoelectric detectors based on the compound ferroelectric single crystal assembly. The result indicated that the unique two-dimensional perovskite structure endows (iPA)₂EA₂Pb₃I₁₀ with strong optical anistropy, narrow bandgap (1.80 eV) and fascinating photoelectric features (on/off ratio=10³). Strikingly, the fabricated photodetectors based on ferroelectric crystal (iPA)₂EA₂Pb₃I₁₀ manifest excellent photoelectric features, including large dichroism ratio (2.3), high responsibility (193 mA•W^–1) and photodetectivity (7.0×10¹¹ Jones), better than most photodetector based on intrinsic optical anisotropy of 2D materials. This work will be of great significance to lay a foundation for the exploring of multifunctional halide perovskites and points out the direction for bulk grown of highly anisotropic halide perovskite ferroelectric crystals and promotes their further applications in highly polarized-sensitive photodetection.

Organic light-emitting transistor (OLET) is a kind of revolutionary miniaturized optoelectronic device which integrates the functions of an organic field-effect transistor and an organic light-emitting diode in a single device. This unique integrated architecture of OLET makes it show great potential for studies of fundamental properties of organic materials, applications in fields of novel organic flexible display/lighting technology, organic electrically-pumped lasers as well as on-chip optoelectronic systems. To realize the full potential of these technologies, the development of key materials and optimization of device fabrication techniques including device structures and processing conditions are highly required. Based on the comprehensive study of the development and basic scientific problems in the OLET field, in the past five years, the authors' research group and collaborators carried out systematical exploratory researches with focuses on the development of high mobility emissive organic semiconductors and construction of high performance OLETs with line- and area-feature emission. Up to now, a series of achievements have been obtained. For instance, we developed a series of anthracene- and fluorene-based high mobility emissive organic semiconductors from the origin of molecular design innovation, which overcomes the science bottleneck of impossibility for integrating high charge carrier mobility and strong emission in the same molecule. Furthermore, this molecular design concept also shows a certain feasibility for the development of other small molecular systems and high mobility emissive conjugated polymers. Moreover, with the mind of integrating the advantages of area-emission of vertical OLET and good gate-tunability and stability of planar OLET, we propose a new area-emission planar OLET architecture, which exhibits a large aperture ratio of over 80% due to the arbitrary tunability of device structure. These preliminary experimental researches and results will provide valuable guidelines for future research of OLETs and their related fields.

Bacterial infection and resistance have threatened public health and it is necessary to develop a novel and efficient antibacterial agent. Metal-organic frameworks (MOFs) have been widely studied and applied in the antibacterial field. The porous carbon frameworks could provide intrinsic conditions to avoid the agglomeration and avail the stabilization of metal nanoparticles, which may be some synergies. Herein, a novel kind of AgNPs@ZIF-67 composite nanoparticles was prepared by a green, rapid, and cost-effective method, during which zeolitic imidazolate framework-67 (ZIF-67) acted as a template and small silver nanoparticles (AgNPs) could be facilely prepared in situ by the reduction of silver ions with fresh sodium borohydride (NaBH₄). Specifically, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images confirmed the existence of as-prepared AgNPs with average diameters of (7.05±0.09) nm and the introduction of AgNPs did not alter the size and rhombic dodecahedron-type morphology of ZIF-67. Energy-dispersive X-ray spectroscopy (EDS) elemental mapping revealed that AgNPs@ZIF-67 mainly contained uniformly dispersed C, N, O, Co and Ag elements. And the loading ratio of Ag weight content was 0.98% in it. The X-ray diffraction (XRD) pattern of the AgNPs@ZIF-67 sample showed a series of typical and sharp diffraction peaks in the (011), (002), (112), and (222) planes but no obvious peaks attributed to the AgNPs, which exhibited the formation of phase-pure ZIF-67 and well-dispersed of metallic Ag in ZIF-67. Zeta potentials showed a higher potential of ZIF-67 (+25.6 mV) than AgNPs@ZIF-67 (+17.7 mV), indicating the load of negative charged AgNPs and good stability of the as-obtained AgNPs@ZIF-67. Furthermore, Staphylococcus aureus (S. aureus) (ATCC 6538) was used in the antibacterial assay and the bacterial concentration was regarded as 1×10⁸ CFU• mL^–1 when the OD₆₀₀ value of the suspensions was 0.1. The in vitro minimum inhibitory concentration (MIC) of AgNPs@ZIF-67, ZIF-67 were 300, 350 µg•mL^–1, respectively. The antibacterial efficiency of AgNPs@ZIF-67, ZIF-67, and AgNPs at 24 h were 99.889%, 57.192%, and 26.433%, respectively. It was illustrated that the decoration of AgNPs could significantly improve the antibacterial ability of ZIF-67 nanomaterials. Moreover, SEM images of S. aureus showed that AgNPs@ZIF-67 did more serious damage to the cell membrane than ZIF-67. This work provided a facile method to fabricate the AgNPs@ZIF-67 composite nanoparticles, which was demonstrated as a promising antibacterial material based on the synergistic effect of AgNPs and ZIF-67.

Magnesium hydride is a promising hydrogen storage material due to its high hydrogen storage capacity, low cost and abundance. The gravimetric and volumetric hydrogen capacities of MgH₂ are about 7.6% and 110 g/L, respectively. However, its sluggish de/re-hydrogenation rates and high operating temperatures ranging between 300~400 ℃ restrict it in practical applications. Catalyzing has been proved to be an effective method to improve its hydrogen storage performance. In this work, V₂O₅ has been chosen as a catalyst for improving the de/re-hydrogenation kinetics of MgH₂. Experimental results show that MgH₂ doping with V₂O₅ (w=5%) has the best hydrogen storage properties among the doping amounts (w) of 2.5% to 10%. Comparing with the pristine MgH₂, the addition of V₂O₅ (w=5%) significantly improves the ab/desorption behaviors of MgH₂. V₂O₅ (w=5%) doped MgH₂ starts releasing hydrogen from 175 ℃ which is 89 ℃ lower than the additive-free as-milled MgH₂. It should be noted that the dehydrogenated V₂O₅ (w=5%) doped MgH₂, is able to absorb 2.1% and 3.8% in the mass fraction of H₂ respectivity, within 30 and 180 min at room temperature and 3 MPa hydrogen pressure. Under the same hydrogen pressure, when the temperature is increased to 300 ℃, the mass fraction of H₂ absorbed by the sample is as high as 6.7% within 1 min. In addition, the catalyzed system shows a good reversibility, after 20 cycles, the hydrogen capacity maintains above 6.0%. Compared with the pure MgH₂, the dehydrogenation apparent activation energy of V₂O₅ catalyzed sample decreased from 108 to 56 kJ•mol^–1. X-Ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) have been employed to investigate its reaction mechanism. It shows that the formation of metallic vanadium and low-oxidation vanadium during ball milling and dehydrogenation process play important roles in improving the de/re-hydrogenation kinetics of MgH₂/Mg system.