离子液体-海藻酸钠复合凝胶的制备及界面太阳能海水淡化性能

doi:10.6023/A26040132

摘要/Abstract

开发高效、耐盐的太阳能界面蒸发器, 以实现海水的高效淡化和长期稳定运行, 仍面临严峻挑战. 本工作构建了掺杂1-丁基-3-甲基咪唑氯盐的海藻酸盐复合凝胶蒸发器(BPS-Cl), 该咪唑类离子液体改性凝胶具有各向异性层状多孔结构与优异水分传输性能. 基于独特的抗聚电解质效应, 该蒸发器在一个太阳照射下, 在质量分数为3.5%的NaCl溶液中蒸发速率达2.86 kg•m⁻²•h⁻¹, 较纯水条件下(2.54 kg•m⁻²•h⁻¹)提升12.59%, 光热转换效率为89.25%; 即使在w(NaCl)=10%高盐浓度下, 蒸发速率仍可达2.32 kg•m⁻²•h⁻¹, 显示出良好的高盐适应性. 此外, BPS-Cl蒸发器表现出优异的自排盐性能, 在w(NaCl)=3.5%的水溶液中连续运行36 h, 平均蒸发速率稳定在2.84 kg•m⁻²•h⁻¹, 且表面无盐分析出. 户外实验进一步验证了其稳定的淡水生产能力. 本研究为发展高效、抗盐的太阳能驱动海水淡化系统提供了新策略.

关键词: 离子液体, 咪唑氯盐, 海水淡化, 太阳能界面水蒸发

The development of highly efficient and salt-tolerant solar evaporators for sustainable seawater desalination remains a key challenge. Interfacial solar steam generation (ISSG) has emerged as a promising technology for harnessing solar energy to produce fresh water from saline sources. In this work, using polyethyleneimine (PEI) and sodium alginate (SA) as the gel network and reduced graphene oxide (RGO) as the photothermal material, we introduced 1-butyl-3-methylimidazo- lium chloride (BMIMCl) into the gel network, stirred the mixture uniformly, and finally obtained an alginate-based composite hydrogel evaporator doped with a hydrophilic imidazolium ionic liquid (denoted as BPS-Cl) via freeze-drying. The resulting evaporator possesses an anisotropic layered porous structure and favorable water transport capability. Owing to the unique anti-polyelectrolyte effect, the BPS-Cl evaporator achieved an evaporation rate of 2.86 kg•m⁻²•h⁻¹ in NaCl solution with a mass fraction of 3.5% under one-sun irradiation, which is 12.59% higher than that in pure water (2.54 kg•m⁻²•h⁻¹). Under dark evaporation conditions, the mass change of water per unit area per unit time for BPS-Cl was measured, and the corresponding photothermal conversion efficiency was calculated to be 89.25% according to the formula. Even under high-salinity conditions (w(NaCl)=10%), the evaporation rate can reach 2.32 kg•m⁻²•h⁻¹, demonstrating excellent salt tolerance. Moreover, during a 36-hour continuous desalination test in 3.5% NaCl solution (mass fraction), the evaporator exhibited stable performance with an average evaporation rate of 2.84 kg•m⁻²•h⁻¹ and no salt deposition on the surface, highlighting its excellent salt-rejection capability. In the outdoor evaporation experiment, the average evaporation rate of BPS-Cl was stable and reached 1.92 kg•m⁻²•h⁻¹. Meanwhile, the produced fresh water was collected and the ion concentrations of the freshwater were detected, which further validated its stable freshwater production performance. This study provides a novel strategy for the design of efficient and stable solar-driven desalination systems.

Key words: ionic liquid, imidazole chloride salt, seawater desalination, interfacial solar steam

引用此文

郝子涵, 朱啟碧, 申凤娟, 耿丽君, 余旭东. 离子液体-海藻酸钠复合凝胶的制备及界面太阳能海水淡化性能[J]. 化学学报, 2026, 84(9): 1487-1496.

Zihan Hao, Qibi Zhu, Fengjuan Shen, Lijun Geng, Xudong Yu. Fabrication of Ionic Liquid-Sodium Alginate Composite Hydrogels for Interfacial Solar Seawater Desalination[J]. Acta Chimica Sinica, 2026, 84(9): 1487-1496.

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图/表 10

图式1. 添加BMIMCl的BPS-Cl水凝胶制备过程示意图

Scheme 1. Schematic illustration of the fabrication process of BPS-Cl hydrogel with addition of BMIMCl

图1. (a) BPS-0干凝胶、(b) BPS-P干凝胶、(c) BPS-Cl干凝胶的扫描电镜图; (d) SA、PEI与SA-PEI、(e) PEI、BMIMCl与PEI-BMIMCl、(f) SA、BMIMCl与SA-BMIMCl的傅里叶变换红外光谱图

Figure 1. SEM images of (a) BPS-0 xerogel; (b) BPS-P xerogel; (c) BPS-Cl xerogel; FTIR spectra of (d) SA, PEI and SA-PEI; (e) PEI, BMIMCl and PEI-BMIMCl; (f) SA, BMIMCl and SA-BMIMCl

图2. (a)不同BPS样品紫外-可见-近红外吸收光谱及太阳光谱, 插图为对应波段下的局部放大图谱; (b)不同凝胶的水接触角照片; (c) BPS-0, BPS-P和BPS-Cl在不同质量分数NaCl溶液中的水传输速率

Figure 2. (a) UV-Vis-NIR absorption spectra of different BPS samples and solar spectrum, the inset shows the partially enlarged view of the corresponding wavelength range; (b) The photos display the water contact angle of the different gels; (c) Water transport rates of BPS-0, BPS-P and BPS-Cl in different brine concentrations

图3. (a)不同盐浓度下BPS-Cl的上表面温度; (b)不同蒸发器在不同盐浓度下的蒸发速率; (c)不同蒸发器在不同盐浓度下的能量效率; (d) BPS-Cl 与文献报道凝胶基蒸发器的蒸发速率对比

Figure 3. (a) The upper surface temperature of BPS-Cl in different brine concentrations; (b) Evaporation rates of different evaporators in different brine concentrations; (c) The energy efficiency of different evaporators in different brine concentrations; (d) Evaporation rate comparison between BPS-Cl and reported gel-based evaporators

Solution composition	Time for rapid heating /min	Upper surface temperature/℃	Time to reach equilibrium/min	Upper surface temperature/℃
pure water	10	30.0	25	31.9
w(NaCl)=3.5%	10	29.7	25	31.4
w(NaCl)=10%	10	30.5	25	32.2

表1. 不同盐浓度下BPS-Cl的上表面温度

Table 1. The upper surface temperature of BPS-Cl in different brine concentrations

图4. 不同样品中水的拉曼光谱分峰拟合图. (a) BPS-Cl纯水体系; (b) BPS-Cl, w(NaCl)=3.5%水溶液; (c) BPS-0, w(NaCl)=3.5%水溶液; (d) BPS-P, w(NaCl)=3.5%水溶液. 其中3245 cm⁻1和3401 cm⁻1处特征峰归属于强氢键结合的自由水(FW), 3502 cm⁻1和3630 cm⁻1处特征峰归属于弱氢键结合的中间水(IW)

Figure 4. Deconvoluted Raman spectra of water for different samples. (a) BPS-Cl, pure water; (b) BPS-Cl, w(NaCl)=3.5% brine; (c) BPS-0, w(NaCl)=3.5% brine; (d) BPS-P, w(NaCl)=3.5% brine. Peaks at 3245 cm⁻1 and 3401 cm⁻1 are attributed to strongly hydrogen-bonded free water (FW), whereas peaks at 3502 cm⁻1 and 3630 cm⁻1 belong to weakly hydrogen-bonded intermediate water (IW)

图5. (a)不同盐浓度下BPS-Cl的IW/FW比值; (b) w(NaCl)=3.5%盐水中BPS-0与BPS-P的IW/FW比值

Figure 5. (a) The ratio of IW/FW of BPS-Cl in different brine concentrations; (b) The ratios of IW/FW of BPS-0 and BPS-P in w(NaCl)=3.5% brine

图式2. BPS-Cl提升盐水中水分蒸发性能的作用机理示意图

Scheme 2. The proposed mechanism that BPS-Cl enhances the water evaporation performance in brine

图6. (a)在BPS-Cl中加入1 g固体NaCl并将其漂浮于w(NaCl)=3.5%盐水中的盐溶解过程; (b) w(NaCl)=3.5%盐水中不同凝胶的盐通量; (c) 1倍太阳光照下BPS-Cl在w(NaCl)=3.5%盐水中的36 h连续蒸发测试, 插图为蒸发前后的凝胶表面形貌; (d) BPS-Cl在w(NaCl)=3.5%盐水中的循环稳定性

Figure 6. (a) The process of salt dissolution in the BPS-Cl placed 1 g of solid NaCl and floated on the w(NaCl)=3.5% brine; (b) Salt flux of different gels in w(NaCl)=3.5% brine; (c) Continuous 36 hours evaporation test of BPS-Cl in w(NaCl)=3.5% brine under one sun irradiation. The illustration shows the gel surface before and after evaporation; (d) Cycling stability of BPS-Cl in w(NaCl)=3.5% brine

图7. (a)户外实验中界面太阳能蒸汽发生(ISSG)装置的实物照片; (b)户外测试中的环境温度与相对湿度; (c)户外测试中的太阳辐照强度与平均蒸发速率; (d)光热蒸发前后的离子浓度

Figure 7. (a) Photos of ISSG device in outdoor experiment; (b) The ambient temperature and relative humidity in outdoor test; (c) The solar intensity and average evaporation rate in outdoor test; (d) Ion concentrations before and after solar-thermal evaporation

参考文献 39

[1]	United Nations Educational,Scientific and Cultural Organization, The United Nations World Water Development Report 2024: Water for Prosperity and Peace. Paris: UNESCO 2024.
[2]	Lewis N. S. Science 2016, 351, aad1920.
[3]	Shannon M. A.; Bohn P. W.; Elimelech M.; Georgiadis J. G.; Mariñas B. J.; Mayes A. M. Nature 2008 452, 301. doi: 10.1038/nature06599
[4]	Su Y.; Gu R.; Li Y.; Wu W.; Yu Z.; Cheng S. Adv. Funct. Mater. 2025, 2420651.
[5]	Chen Y.; Shen L.; Qi Z.; Luo Z.; Li X.; Bao H. Nat. Sustain. 2025, 8, 162. doi: 10.1038/s41893-024-01485-6
[6]	Chen Y.; Bao H. Nat. Sustain. 2025, 8, 123. doi: 10.1038/s41893-024-01497-2
[7]	Yang D.; Shi X.; Zhang J.; Bu X. Acta Chim. Sinica 2023, 81, 1052 (in Chinese). doi: 10.6023/A23040148
	(杨地, 史潇凡, 张冀杰, 卜显和, 化学学报, 2023, 81, 1052.) doi: 10.6023/A23040148
[8]	Hu Y.; Ma H.; Wu M.; Lin T.; Yao H.; Liu F.; Cheng H.; Qu L. Nat. Commun. 2022, 13, 4335. doi: 10.1038/s41467-022-32051-3
[9]	Zhang H.; Shen X.; Kim E.; Wang M.; Lee J.; Chen H.; Zhang G.; Kim J. Adv. Funct. Mater. 2022, 32, 2111794. doi: 10.1002/adfm.v32.19
[10]	Chen X.; Ye Q.; Shi C.; Zhang L.; Zhou P.; Chen M. Nano Res. Energy 2025, 4, e9120152.
[11]	Chen L.; Sun Y.; Ma C.; Sun Y.; Peng S.; Cao X.; Yang L.; Ma C.; Zhao H.; Wang H.; Zhang D.; Liu Q.; Liu Z.; Yuan Y.; Wang N. Chem. Eng. J. 2023, 475, 146177. doi: 10.1016/j.cej.2023.146177
[12]	Wang Z.; Gao J.; Zhou J.; Gong J.; Shang L.; Ye H.; He F.; Peng S.; Lin Z.; Li Y.; Caruso F. Adv. Mater. 2022, 35, 2209015. doi: 10.1002/adma.v35.1
[13]	Wu X.; Wang Y.; Wu P.; Zhao J.; Lu Y.; Yang X.; Xu H. Adv. Funct. Mater. 2021, 31, 2102618. doi: 10.1002/adfm.v31.34
[14]	Zhang L.; Zhang Y.; Zou M.; Yu C.; Li C.; Gao C.; Dong Z.; Wu L.; Song Y. Adv. Funct. Mater. 2023, 33, 2300318. doi: 10.1002/adfm.v33.24
[15]	Wu L.; Dong Z.; Cai Z.; Ganapathy T.; Fang N.; Li C.; Yu C.; Zhang Y.; Song Y. Nat. Commun. 2020, 11, 521. doi: 10.1038/s41467-020-14366-1
[16]	Zhao W.; Gong H.; Song Y.; Li B.; Xu N.; Min X.; Lin G.; Zhu B.; Zhou L.; Zhang X.; Zhu J. Adv. Funct. Mater. 2021, 31, 100025.
[17]	Gokturk P. A.; Sujanani R.; Qian J.; Wang Y.; Katz L. E.; Freeman B. D.; CrumLin E. J. Nat. Commun. 2022, 13, 5880. doi: 10.1038/s41467-022-33592-3
[18]	Zhang H.; Li X.; Liu X.; Du Y.; Xie W.; Zheng S.; Yang L.; Shi J.; Jing D. Chem. Eng. J. 2023, 473, 145484. doi: 10.1016/j.cej.2023.145484
[19]	Jiang H.; Liu X.; Wang H.; Wang D.; Guo Y.; Wang D.; Gao G.; Wang X.; Hu C. Chin. Sci. Bull. 2023, 68, 1640. doi: 10.1016/j.scib.2023.07.011
[20]	Li Z.; Zeng Q.; Yu G.; Li Z.; Ye C.; Liu Y.; Qin J. Macromol. Rapid Commun. 2008, 29, 136. doi: 10.1002/marc.v29:2
[21]	Qian J.; Guo J.; Li Y.; Yu X. Desalination 2024, 575, 117292. doi: 10.1016/j.desal.2024.117292
[22]	Panja S. K.; Haddad B.; Debdab M.; Kiefer J.; Chaker Y.; Bresson S.; Paolone A. ChemPhysChem 2019, 20, 2542.
[23]	Grenda K.; Idström A.; Evenäs L.; Persson M.; Holmberg K.; Bordes R. J. Appl. Polym. Sci. 2022, 139, e51657.
[24]	Zhu S.; Wu Y.; Chen Q.; Yu Z.; Wang C.; Jin S.; Ding Y.; Wu G. Green Chem. 2006, 8, 325. doi: 10.1039/b601395c
[25]	Li Y.; Chen B.; Yao D.; Gao X.; Chen J.; Lu C.; Pang X. Carbohyd. Polym. 2025, 359, 123588. doi: 10.1016/j.carbpol.2025.123588
[26]	Jiang Y.; An N.; Sun Q.; Guo B.; Wang Z.; Zhou W.; Gao B.; Li Q. Sci. Total Environ. 2022, 837, 155757. doi: 10.1016/j.scitotenv.2022.155757
[27]	Song C.; Jin Y. Int. J. Biol. Macromol. 2025, 316, 144704. doi: 10.1016/j.ijbiomac.2025.144704
[28]	Li Y.; Liu X.; Wang Y.; Bi S.; Li J.; Wang J.; Duo Y.; Zhu Z.; Jin X.; Wang W. Sci. China Mater. 2025, 68, 2850 (in Chinese). doi: 10.1007/s40843-025-3437-6
	(李叶燃, 刘星, 王一璠, 毕圣洁, 李静, 王京博, 朵永超, 朱正涛, 金欣, 王闻宇, 中国科学: 材料, 2025, 68, 2850.)
[29]	Liu W.; Li P.; Li X.; He Y.; An L.; Qu D.; Wang X.; Sun Z. Sci. China Mater. 2023, 66, 1607 (in Chinese). doi: 10.1007/s40843-022-2282-9
	(刘文宁, 李鹏飞, 李湘勤, 何亚倩, 安丽, 曲丹, 汪夏燕, 孙再成, 中国科学: 材料, 2023, 66, 1607.)
[30]	Yang Z.; Cheng H.; Yang Y.; Liu H.; Du F.; Zhang Y. Chem. J. Chinese Universities 2022, 43, 20220181 (in Chinese).
	(杨兆华, 成鸿静, 杨弋, 刘辉, 杜飞鹏, 张云飞, 高等学校化学学报, 2022, 43, 20220181.) doi: 10.7503/cjcu20220181
[31]	Sekine Y.; Ikeda-Fukazawa T. J. Chem. Phys. 2009, 130, 034501. doi: 10.1063/1.3058616
[32]	Lei C.; Guan W.; Guo Y.; Shi W.; Wang Y.; Johnston K. P.; Yu G. Angew. Chem. Int. Ed. 2022, 61, e202208487.
[33]	Zhu F.; Wang L.; Demir B.; An M.; Wu Z.; Yin J.; Xiao R.; Zheng Q.; Qian J. Mater. Horiz. 2020, 7, 3187. doi: 10.1039/D0MH01259A
[34]	Choi W.; Park S.; Kwon J.; Jang E.; Kim J.; Heo J.; Hwang Y.; Kim B.; Moon J.; Jung S.; Choi S.; Lee H.; Ahn H.; Hong J.; ACS Nano 2021, 15, 6811. doi: 10.1021/acsnano.0c10431
[35]	Zhu Q.; Liu M.; Li Y.; Feng G.; Xu Z.; Geng L.; Yu X. Sep. Purif. Technol. 2025, 368, 133033. doi: 10.1016/j.seppur.2025.133033
[36]	Geng L.; Zhang X.; Li Y.; Feng G.; Yu X. Langmuir 2024, 40, 13412. doi: 10.1021/acs.langmuir.4c00570
[37]	Zhou H.; Han L.; Yang M.; Wu X.; Li J.; Ma H.; Zhang B. Desalination 2023, 556, 116567. doi: 10.1016/j.desal.2023.116567
[38]	Wang Z.; Jin R.; Zhang S.; Han X.; Guo P.; Jiang L.; Heng L. Adv. Funct. Mater. 2023, 33, 2306806. doi: 10.1002/adfm.v33.47
[39]	Yang H.; Sun Y.; Peng M.; Cai M.; Zhao B.; Li D.; Liang Z.; Jiang L. ACS Nano 2022, 16, 2511. doi: 10.1021/acsnano.1c09124