Improved Mass-Transfer Enhances Photo-Driven Dye Degradation and H 2 Evolution over a Few-Layer WS 2 /ZnO Heterostructure.

In this study, we observed the enhanced photocatalytic activity of a few-layer WS 2 /ZnO (WZ) heterostructure toward dye degradation and H 2 production. The few-layer WS 2 acted as a co-catalyst that separated photogenerated electron/hole pairs and provided active sites for reactions, leading to the rate of photocatalytic H 2 production of WZ being 35% greater than that over the bare ZnO nanoparticles. Moreover, vortex-stirring accelerated the mass-transfer of the reactants, leading to the efficiency of dye photodegradation being 3 times higher than that obtained without high-speed stirring. We observed a similar effect for H 2 production, with greater photocatalytic performance arising from the increased mass-transfer of H 2 from the catalyst surface to the atmosphere.