Rational design of molybdenum sulfide/tungsten oxide solar absorber with enhanced photocatalytic degradation toward dye wastewater purification

Integrating advanced technologies into solar-driven water evaporation is gradually considered as a clean and sustainable way to acquire freshwater from saline or wastewater. In this study, thin molybdenum sulfide nanosheet arrays (MoS2 NSAs) modified by tungsten oxide nanoparticles (WO3) were designed. The as-prepared solar absorber could purify water and accomplish photocatalytic degradation of dyes that existed in bulk water via solar-driven water evaporation. Compared with bare MoS2 NSAs, the modification of WO3 enhanced the separation of electrons and holes within the solar absorber, resulting in the improvement of photocatalytic efficiency. The net evaporation rate of the solar absorber reached 0.97 kg m-2h-1 and the degradation rate constant of rhodamine B (RhB) reached 0.101 min-1 under 1 sun. This study successfully combined photothermal conversion and photocatalytic technologies and provided a new method for the treatment of dye wastewater with zero wastewater discharge.