A “battery” like Z-scheme heterojunction photocatalyst fabricated from aminated CdS and Ni3-polyoxometalate for promoted hydrogen production and electron transfer mechanism studies

Abstract

In recent years, composite photocatalysts prepared from semiconductor quantum dots have received great attentions, however, the cases on functionalizing the surface of semiconductor quantum dots and combining them with polyoxometalate are not common. Based on this, a photocatalytic material was assembled from the aminated CdS quantum dots and Ni3-containing polyoxometalate by electrostatic adsorption. Interestingly, it has been found that the light source, electron sacrificial agent and polyoxoanions could form a high-speed electron transfer channel in the photocatlytic process, in which these three components behave like a “switch”, “power source” and “battery” in the system, respectively. Due to the Z-scheme driven effect, the hydrogen production activity of the composite catalyst is 25 times higher than that of the substrate material. This work may provide an insight for studying the electron transfer mechanism of polyoxometalate-based photocatalytic systems.