Wettable photothermal hollow fibers arrays for efficient solar-driven desalination under omnidirectional illumination without salt precipitation

Abstract Solar-driven evaporation based on photothermal materials is emerging as a sustainable fresh water generation technology for alleviating water scarcity. To realize the efficient and stable desalination under omnidirectional illumination, here, a “Pinscreen”-inspired photothermal hollow fibers arrays has been developed for high-efficiency and stable solar-driven evaporation under omnidirectional illumination. In the photothermal arrays design, driven by the capillary action, water was automatically taken up through the lumen side of hydrophilic alumina hollow fiber coated with polypyrrole (PPy), which also shows high light-harvesting. Thanks to the designed morphology of arrays, the evaporation amount of PPy-AHFs arrays is over 0.65 g h−1 even under parallel one-sun illumination. During a long-term desalination, photothermal hollow fibers arrays can realize controllable salt-precipitation attributed to ideal water transport. Our results of wettable photothermal hollow fibers arrays for efficient photothermal evaporation can be considered as a significant attempt to inspire the future development of novel photothermal materials in sustainable desalination.