Construction of Mo-Based p-n Heterojunction with Enhanced Oxidase-Mimic Activity for AOPs and Antibiofouling.

Abstract

Advanced oxidation processes (AOPs) are efficient methods to remove poisonous organic pollutants from water. But in AOPs, additional radical providers, such as H2O2, persulfate, and permonosulfate, are indispensable, which not only add the risk of secondary pollution but also increase cost and complexity in operation. To resolve this problem, nanozymes with oxidase-mimic activity are a prospective choice, which can convert O2 in the air to ·OH and degrade organic pollutants. Here, CoMoO4/MoS2, a nanozyme with excellent oxidase-mimic activity, is synthesized. In the structure, the p-n heterojunction generates between p-type CoMoO4 and n-type MoS2. Energy band analysis and theoretical calculations suggest the p-n heterojunction intensifies adsorption toward O2, which improves oxidase-mimic activity. This facilitates the generation of ·OH and improves organic pollutant degradation performance with AOPs. Furthermore, CoMoO4/MoS2 also exhibits an antibiofouling ability due to the existence of ·OH. This work clarifies the connection between the structure and oxidase-mimic activity for nanozymes with the p-n heterojunction. More importantly, a new AOP without additional radical providers is developed based on oxidase-mimic activity.