Narrow bandgap semiconductor decorated wood membrane for high-efficiency solar-assisted water purification

Abstract

Solar steam generation is a promising solar energy conversion technology due to its potential applications in water treatment, liquid–liquid phase separation, and sterilization. Therefore, finding highly efficient solar-thermal conversion materials and structures is highly desirable. Here, we developed a membrane consisting of a narrow bandgap semiconductor of CuFeSe₂ nanoparticles (NPs) decorated wood (coded as black wood membrane), for high-efficiency solar steam generation. The CuFeSe₂ NPs display a desirable narrow bandgap of 0.45 eV, and can be used as a novel light absorbing material for highly efficient solar-thermal conversion. Wood served as the substrate for the CuFeSe₂ NPs due to its excellent properties: a mesoporous structure, low density, heat-localization, low thermal conductivity, high hydrophilicity, and cost-effectiveness. All the properties of the designed CuFeSe₂ NP-decorated wood membrane make it an ideal absorber for solar steam generation, allowing it to achieve a high solar thermal efficiency of 86.2% under 5 kW m⁻². Moreover, the CuFeSe₂ NP-decorated wood membrane is cost-efficient and scalable, making it a fantastic material for various applications involving light absorption, photothermal conversion, and water purification.