Fabrication of high-performance graphene oxide/CuO/Cu2O film-coated copper foam for interfacial solar-driven water evaporation

Interfacial solar-driven water evaporation (ISDWE) technology has received tremendous attention for its potential application in clean water production. However, its practical application requires more robust, efficient and multifunctional photothermal materials. For this case, growth of CuO/Cu2O film and graphene oxide assembly were successively conducted on the surface of Cu foam in this study, making positive contribution to the ISDWE performance. By the growth of CuO/Cu2O film, solar light utilization ability and surface wettability of Cu foam were enhanced, and the ISDWE performance was increased. It was also found that the pores per inch (PPI) value and thickness of Cu foam have a double-edged sword effect on the ISDWE performance. This could originate from the synergetic effect of surface area for evaporation, water pumping and vapor diffusion abilities. Among various PPI values and thicknesses, Cu@CuO/Cu2O foam with PPI value of 60 and 3 mm thickness demonstrated optimal ISDWE performance. By subsequent graphene oxide modification, the solar light utilization ability and surface wettability were further enhanced, the water evaporation rate reached 1.539 kg m−2 h−1, and the water evaporation efficiency was 96.64%. Moreover, the combination of CuO/Cu2O film and graphene oxide resulted in superior photocatalytic property on degrading Rhodamine B solution. The obtained results could provide important theoretical and practical reference value for the design of advanced photothermal materials.