▎ 摘　　要

Production of clean water from seawater and wastewater is significant through photothermal evaporation using unlimited solar energy. Here, we constructed a double-layer-structure evaporator (DLSE) consisting of nickel foam@reduced graphene oxide-carbon nanotube (NF@RGO-CNT) as a solar absorber and an expanded polyethylene foam (EPE)/thermoelectric (TE) module as a heat insulator, which was used in various water purification processes and simultaneous electricity generation. The reduced graphene oxide covered on the surface of nickel foam increases broad-band absorption of sunlight and weakens the thermal emittance, and its coarse surface decreases the reflectance of light, which ensures the largest photo-to-heat conversion efficiency. Compared with the pristine nickel foam, NF@RGO-CNT has a low thermal conductivity to achieve localized high temperatures, which favors the evaporation of water on the interfacial surface. As such, a high water evaporation rate of 1.37 kg m-2 h-1 together with a photothermal conversion efficiency of 96.4% was achieved over the NF@RGO-CNT under 1 kW/m2. Meanwhile, the thermoelectricity during solar evaporation is generated by utilizing the TE module instead of EPE, in which a maximum output power of 0.251 W m-2 was achieved under 1 kW/m2. In addition, clean water can be produced using DLSE equipment from various water sources such as brine water, organic wastewater, seawater, and lake water, in which the quality of the evaporated water is better than drinkable water standard, and the evaporation performance is comparable to that of pure water.