煤焦油衍生多孔碳基水凝胶太阳能蒸发器，用于高效废水净化

摘要：多孔碳基水凝胶蒸发器因其广泛的可获得性、优异的亲水性和丰富的多孔结构，在太阳能驱动的水蒸发领域显示出广泛的应用潜力。然而，单分子交联水凝胶封闭的孔隙结构和纳米多孔碳材料高昂的生产成本不仅影响了碳基水凝胶的耐盐性，也限制了其大规模应用。本文，新疆大学Yakun

1成果简介

多孔碳基水凝胶蒸发器因其广泛的可获得性、优异的亲水性和丰富的多孔结构，在太阳能驱动的水蒸发领域显示出广泛的应用潜力。然而，单分子交联水凝胶封闭的孔隙结构和纳米多孔碳材料高昂的生产成本不仅影响了碳基水凝胶的耐盐性，也限制了其大规模应用。本文，新疆大学Yakun Tang、刘浪教授团队在《Langmuir》期刊发表名为”Dual Cross-Linking Coal Tar-Derived Phenolic Resin Porous Carbon-Based Hydrogel Solar Evaporators for Efficient Wastewater Purification的论文”研究将聚乙烯醇（PVA）/聚乙二醇（PEG）双网络水凝胶与宽带太阳能吸收、高性价比的煤焦油基酚醛树脂多孔纳米碳片（APRC）整合在一起，开发了一种均匀多孔的 APRC-PVA/PEG 水凝胶蒸发器。

蒸发器丰富的孔隙和三维双网络结构确保了优异的水传输性能和较高的光吸收率（≈98%）。同时，蒸发器的低导热系数（干：0.09 W m-1 K-1；湿：0.29 W m-1 K-1）减少了散装水的热损失，使其在1太阳光照射下的水蒸发率达到 1.45 kg m-2 h-1，蒸发焓低至1614.605 J g-1。该蒸发器在盐水、工业废水和有机染料废水领域也显示出良好的应用潜力。

2图文导读

图1、 Structure and hydrophilic characterization of APRC: (a) SEM image, (b,c) TEM images, (d) Raman fitting spectra, (e) IR spectra, and (f) contact angle of PRC and APRC.

图2. (a) Schematic diagram of cross-linking reaction of APRC-PVA/(7)PEG hydrogel and SEM images of (b) APRC-PVA, (c) APRC-PVA/(5)PEG, (d) APRC-PVA/(7)PEG, and (e) APRC-PVA/(9)PEG.

图3. Physical properties of APRC-PVA/(7)PEG: (a) ultralightweight nature, (b) diameter comparison in dry and wet condition, (c) quality comparison in dry and wet condition, (d) water transport, and (e) changes in mechanical properties.

图5. (a) Schematic diagram of a solar-driven interface evaporation device. Under the light intensity of 1 kW m–2, (b) mass change curve and (c) evaporation rate diagram of APRC-PVA/PEG solar evaporators with varying PEG concentrations, (d) cycle stability; under different sunlight intensity (0.5–2 kW m–2), characterization of APRC-PVA/(7)PEG by photothermal water evaporation: (e) mass change curve with time, (f) water evaporation rate and photothermal conversion efficiency diagram, (g) temperature curves, and (h) IR images of the APRC-PVA/(7)PEG surface upon reaching thermal equilibrium.

图6. Under the light intensity of 1 kW m–2, salt resistance of APRC-PVA/(7)PEG evaporator: (a) mass change at different salinities, (b) evaporation rate, (c) mass and evaporation rate changes for 12 h at 3.5 wt % NaCl, (d) changes in the surface after 12 h of continuous exposure to light, and (e) surface salt dissolution.

图7. Stable water evaporation performance of APRC-PVA/(7)PEG evaporator: (a) mass and evaporation rate changes of in simulated brackish water solution for 12 h, (b) changes in the surface after 12 h of continuous exposure to light, (c) ion concentrations of brackish water before and after purification, (d) mass and evaporation rate changes, (e) rejection of five heavy metal ions (Cr3+, Ni2+, Cu2+, Zn2+, and Pb2+) in brackish water, and (f) ion concentrations before and after purification in simulated industrial wastewater solution for 12 h.

图8. Mass and evaporation rate changes of APRC-PVA/(7)PEG in methyl orange solution (a); rhodamine B solution (b); methyl blue solution (c) under 1 sun; UV–vis spectra of purification before and after (d) methyl orange solution; (e) rhodamine B solution; and (f) methyl blue solution.

3小结

在这项工作中，我们提出了一种基于煤焦油衍生酚醛树脂的多孔碳纳米片的合成方法，并将其用作光热材料，进一步应用于水凝胶蒸发器的制造。通过调整 PVA/PEG 的用量和交联过程中的反应关系，我们获得了孔径均匀、孔隙率高的双分子交联 APRC-PVA/(7)PEG。水凝胶的三维多孔结构与多孔碳纳米片相结合，使蒸发器的光吸收率高达 97.12%。此外，APRC-PVA/7PEG 特殊的亲水性和相互连接的多孔网络促进了水、蒸汽和离子的高效传输，在 1 kW m-2 的条件下，水蒸发率达到 1.45 kg m-2 h-1，蒸发焓降低到 1614.605 J g-1。此外，双重交联策略优化了 APRC-PVA/7PEG 的孔隙结构，显著提高了其吸附能力和离子传输效率，因此在净化盐水、含重金属废水和有机污染物方面具有非凡的潜力。

文献
:https://doi.org/10.1021/acs.langmuir.4c05279