Porous Hydrogel Photothermal Conversion Membrane to Facilitate Water Purification

Solar water purification technology is one of the most potent methods to obtain freshwater due to its low cost and non-polluting characteristics. However, the purification efficiency is limited by the high ion concentration, organic pollution, and biological pollution during the actual water purification process. Here, we report a porous hydrogel membrane (Fe/TA-TPAM) for the purification of high ion concentration and contaminated water. The hydrogel membrane exhibits good light absorption and photothermal conversion ability, which shows high evaporation rates (1.4 kg m-2 h-1) and high solar efficiency for seawater. Furthermore, with the introduction of tannic acid (TA) and Ti3C2 MXenes, the Fe/TA-TPAM hydrogel membrane exhibits satisfied purification properties for organic-contaminated and biologically contaminated water. The excellent purification effect of Fe/TA-TPAM under light not only confirms the rationality of the hydrogel porous design and in situ generation of photosensitizer in improving the photothermal performance but also provides a novel strategy for designing advanced photothermal conversion membranes for water purification.