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

Abstract

Recent developments in integrating photocatalysis into solar-driven interfacial water evaporation have attracted much attention. Herein, β-In2S3 nanosheets decorated 2H phase MoS2 nanosheet arrays (MSIS) were proposed for synchronous solar-driven water evaporation and photodegradation of organic pollutants. The modification of hydrophobic 2H phase MoS2 with In2S3 switched the surface wettability. The intrinsic narrow bandgaps of both MoS2 and In2S3 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 MoS2 and In2S3. 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.