Reduced graphene oxide composite nanowood for solar-driven interfacial evaporation and electricity generation

Solar-driven interfacial evaporation (SDIE) is considered one of the most promising technological approaches to solve the freshwater shortages. Based on renewable wood, we fabricated the nanowood loaded with reduced graphene oxide (RGO@Nanowood) with high SDIE performance. Its superior performance benefits from three aspects: Firstly, the cellulose network in nanowood treated by delignification contains many hydrophilic groups, which significantly improves the hydrophilicity and can combine with water molecules through hydrogen bonds to generate more activated water, thereby reducing the enthalpy of evaporation. Secondly, the photothermal conversion capability of RGO@Nanowood was significantly improved by loading RGO with an impregnation-reduction method. Finally, the 2D water supply strategy achieves an ideal balance of water transport and thermal management and controls the water content within the pore channels to expose more evaporation space. Under simulated sunlight (1.0 kW m −2 ), the evaporation rate and evaporation efficiency of RGO@Nanowood were 2.26 kg m −2 h −1 and 92.71 %, respectively. In the outdoor experiment, the daily freshwater production of 6.39 kg m −2 was obtained on sunny days. Furthermore, the hydroelectric effect of RGO@Nanowood under solar-driven evaporation proved its potential for power generation applications.