Fabrication of a Z-scheme MoS2/CuO heterojunction for enhanced 2-mercaptobenzothiazole degradation activity and mechanism insight

Abstract

A Z-scheme MoS₂/CuO photocatalyst is successfully developed using a hydrothermal and calcination method, which has excellent activity (96%) in the degradation of 2-mercaptobenzothiazole (MBT) under visible light irradiation. The reaction rate constants of MBT degradation on the MoS₂/CuO heterojunction are 8 and 6 times higher than those of pure MoS₂ and the original CuO, respectively. The as-prepared photocatalyst was characterized using XRD, SEM, XPS and electrochemistry measurement. From the experimental results, the significantly enhanced photocatalytic activity is mainly ascribed to the formation of a Z-scheme heterostructure between MoS₂ nanosheets and flower spherical CuO, effectively improving the separation efficiency of photogenerated carriers. What is remarkable is that the Z-scheme electron transfer process leads to a large accumulation of photogenerated electrons and holes, improving the oxidation and reduction properties of CuO and MoS₂. Moreover, an intensive study of the mechanism has proved that holes, superoxide radicals and hydroxyl radicals are all active substances in the degradation process. This study opens up a new way to devise novel and highly efficient MoS₂-based photocatalysts for the degradation of organic pollutants.