A high-efficiency solar water evaporation-photocatalysis system achieved by manipulating surface wettability and constructing heterojunction

• A heterostructure solar absorber composed of In 2 S 3 nanosheets and MoS 2 nanosheet arrays was constructed. • The superior hydrophilicity and heterojunction interfaces collaboratively improved the performance of solar water evaporation-photocatalysis systems. • A 4.2-fold enhancement in photocatalytic rate constant was achieved without compromising on solar-driven water evaporation. Recent developments in integrating photocatalysis into solar-driven interfacial water evaporation have attracted much attention. Herein, β-In 2 S 3 nanosheets decorated 2H phase MoS 2 nanosheet arrays (MSIS) were proposed for synchronous solar-driven water evaporation and photodegradation of organic pollutants. The modification of hydrophobic 2H phase MoS 2 with In 2 S 3 switched the surface wettability. The intrinsic narrow bandgaps of both MoS 2 and In 2 S 3 endowed the solar absorber with a solar absorptance of 96.0%, and the light utilization of the MSIS was further improved due to its hydrophilicity during solar-driven interfacial water evaporation. Moreover, the MSIS not only boosted the solar-driven interfacial water evaporation by tailoring the wettability of the solar absorber, but also enhanced its photocatalytic degradation over organic pollutants by the formation of heterojunction interfaces between MoS 2 and In 2 S 3 . Specifically, the optimal solar absorber, only composed of semiconductors, exhibited a 4.2-times enhancement in photocatalytic rate constant without the compromise on solar-driven water evaporation (achieving an evaporation rate of 1.56 kg·m –2 ·h –1 under one sun). The heterojunction-based solar absorber featuring favorable hydrophilicity offered exciting opportunities to construct the high-efficiency solar water evaporation-photocatalysis system for the treatment of contaminated water.