Reduced graphene oxide/Cu7·2S4 composite hydrogels for highly efficient solar steam generation

Solar steam generation is an attractive technology for harvesting solar energy to produce fresh water from sewage and sea water. Designing new photothermal materials is one of the feasible methods to improve the efficiency of photothermal conversion, which has aroused people's great interest. Herein, a new composite of reduced graphene oxide (RGO)/Cu 7·2 S 4 polyvinyl alcohol (PVA)/polyacrylamide (PAM) hydrogels is prepared for enhanced solar water generation. As a metal-like plasma, Cu 7·2 S 4 can increase light absorption of sheet RGO in the entire spectrum by a localized surface plasmon resonance (LSPR) effect. The double-component pore structure of PVA/PAM hydrogel can improve the effect of water replenishment and drainage, so the device can achieve a high evaporation rate (2.19 kg m −2 h −1 ). The low cost, high efficiency, stability, and environmental sustainability of the solar evaporator make it a promising material in the field of seawater desalination . • RGO/Cu 7·2 S 4 PVA/PAM–based hydrogel (RGO/CuS) for solar steam generation. • RGO/CuS shows a good stability and high evaporation rate of 2.19 kg m −2 h −1 . • Solar evaporation system exhibits a high light-absorption and excellent mechanical properties.