Efficient H2O2 dissociation and formation on zinc chalcogenides: A density functional theory study

Abstract

Establishing the structure–activity relationship is very important for the design of new catalysts for advanced oxidation process with low energy consumption and high efficiency. In this work, the atomic mechanism of hydrogen peroxide (H2O2) dissociation and formation on zinc chalcogenides (ZnX, where X denotes O, S, Se, and Te) was investigated. It was found that the catalytic activity of H2O2 dissociation and formation on ZnX was determined by the surface micro-engineering construction including surface orientation and heteroatomic doping. H2O2 can dissociate to easily form hydroxyl radicals on ZnO (110), ZnSe (100), ZnTe (110) and ZnTe (100) surfaces, while only the ZnO (110) surface can catalyze water oxidation to form H2O2. Furthermore, the H2O2 selectivity of water oxidation on the ZnO (110) surface can be enhanced by the doping with silver atoms due to the weak adsorption strength of OH*, while introducing copper atom into the ZnO (110) surface can promote H2O2 dissociation. These results not only unveil the mechanism of H2O2 dissociation and formation on ZnX, but also can provide helpful guidance for the development of new catalytic oxidation systems.