Hollow Fiber Array-Based Photothermal-Fenton Evaporator Enabling Efficient Solar-Powered Water Purification

Abstract Solar-driven interfacial evaporation is a sustainable alternative to address the global water crisis involving both freshwater shortage and water pollution, but its application is severely limited by the challenge of simultaneously enhancing evaporation rate and purification efficiency. Herein, a 2.5D hollow fiber array evaporator (FeOCl@CNTs-HFs) that integrated interfacial solar evaporation with a heterogeneous Fenton process was proposed, which enabled effective water purification at a high evaporation rate via the decoupling of heat management and mass transfer limitations. This structure was constructed by vertically arraying functional units on a 2D planar substrate to achieve 3D spatial extension, distinguishing it from continuous 3D bulk foams. FeOCl@CNTs-HFs, fabricated by loading FeOCl nanosheets onto carbon nanotube hollow fibers, achieved highly efficient organic degradation in both condensate and residue solution at 3.93 kg m−2 h−1 under 1.0 kW m−2 irradiation. The superior performance stemmed from synergistic water supply and mass transfer via wall nanopores and lumen, abundant active sites and enhanced light harvesting by FeOCl, and ambient energy capture via the 2.5D spatial design. This work provides a reasonable design for developing functional evaporators that can achieve comprehensive water purification and production simultaneously.