Highly Efficient 3D Evaporator for Interfacial Solar Steam Generation and Wastewater Treatment

Abstract

Solar‐driven interfacial evaporation is one of the means to effectively alleviate the global shortage of freshwater resources without the need for additional energy supply. Although the emergence of various evaporators has improved the evaporation rate and efficiency, it still needs further efforts in terms of improving space utilization, reducing material waste, and enhancing salt resistance. Herein, a 3D bridge evaporator H 1.68 MoO 3 /MS (MS, melamine sponge) is designed, where H 1.68 MoO 3 and MS endow the evaporator with high light absorption in the whole wavelength range and excellent water transport capability, respectively. The support of expanded polystyrene realizes the self‐floating of the device, and the evaporation interface is arched upward and exposed to the air in a bridge shape, effectively improving the space volume utilization rate, reducing material consumption and reducing the heat loss during the evaporation process. Under the sunlight intensity of 1 kW m −2 , the evaporator achieves an evaporation rate of 2.75 kg m −2 h −1 and an evaporation efficiency of 167.0%, meanwhile showing excellent resistance to salt deposition and ability to remove heavy metals and dyes (removal efficiency over 99%). In addition, the evaporation performance of the evaporator remains stable in the evaporation experiment lasting for 10 days, showing good long‐term usability.