Poster Hydrophobic light-to-heat conversion membranes for interfacial heating: towards enhanced solar evaporation

Abstract

Water evaporation driven by solar irradiation plays a critical role in global water cycle as well as in many industrialprocesses. However, the conventional solar evaporation experiences high energy loss and thus low evaporation rate dueto its bulk water heating nature. Aiming at enhancing solar-driven evaporation, herein, we propose and demonstrate a novelinterfacial heating membrane that spontaneously stays at the water-air interface, collects and converts solar light into heat,and locally heats only the water surface. A proof-of-concept membrane is prepared by deposition of light-to-heat conversionmaterial of polypyrrole onto porous stainless steel mesh, followed by hydrophobic modification. Our results confirm thatwith the membrane floating on water surface, a sharp local temperature gradient is generated on the water surface, leading tosignificant water evaporation rate. The study also extends the interfacial heating membrane into solar water distillation andcontributes a solar-driven point-of-use device for freshwater production.