Photothermal water evaporation and purification on the interface evaporator constructed by Cu@Bi2WO6-C

Abstract

Photothermal evaporation is an efficient way to utilize solar energy to desalinate seawater for freshwater resources, which can effectively alleviate the press on accessing to freshwater in water-scarce countries and regions. Here, a highly efficient ternary composite consisting of Bi2WO6, copper and carbon is developed as a photothermal conversion material for solar-driven water evaporation (SDWE) systems. This composite is coated on the top of a base consisting of expanded polystyrene (EPS) foam and hydrophilic fiber paper to construct an interface evaporator, enabling sustainable solar-driven freshwater production. Due to its wide light absorbing range, localized photothermal conversion and low evaporation enthalpy, the solar steam generation (SSG) through Cu@Bi2WO6-based evaporator could be accelerated, thus a high evaporation rate of 2.07 kg m−2 h−1 and an evaporation efficiency of 97 % are obtained under one sun, outperforming the-state-of-art evaporators. This work proposes a feasible way to deal with freshwater shortage.