Abstract: An interconnected open-pore 2.5D Cu/CuO foam-based photothermal evaporator capable of achieving a high evaporation rate of 4.1 kg m-2 h-1 under one sun illumination by exposing one end of the planar structure to air is disclosed. The micro-sized open-pore structure of Cu/CuO foam allows it to trap incident sunlight, and the densely distributed blade-like CuO nanostructures effectively scatter sunlight inside pores simultaneously. The inherent hydrophilicity of CuO and capillarity forces from the porous structure of Cu foam continuously supply sufficient water. Moreover, the doubled working sides of Cu/CuO foam enlarge the exposure area enabling efficient vapor diffusion. The feasible fabrication process and the combined structural features of Cu/CuO foam offer new insight into the future development of solar-driven evaporators in large-scale applications with practical durability.

Abstract: A floatable interfacial solar-driven evaporation structure includes a water impervious thermal insulation layer adapted to float on a body of water, a porous absorber layer on the water impervious thermal insulation layer, and an interlocked non-woven cotton fiber layer having a portion thereof between the water impervious insulation layer and the porous absorber layer and one or more additional portions configured to extend to the body of water to act as a capillary-driven pump to transport water from the body of water to the porous absorber layer. An ultra-black photothermal paint covers the exposed upper surface of the porous absorber layer to convert solar radiation impinging on the ultra-black photothermal paint into heat for use in generating water vapor from water in the porous absorber layer.