Interfacial aspect of ZnTe/In2Te3 heterostructures as an efficient catalyst for the hydrogen evolution reaction

Abstract

In the class of two-dimensional (2D) materials, group III₂–VI₃ compounds have drawn intense attention due to its excellent surface properties. In this work, based on first-principles calculations, we have systematically investigated the structural, electronic, optical and photocatalytic properties of a ZnTe/In₂Te₃ heterostructure, along with its interfacial effects, to design an efficient photocatalyst. We have employed hydrogen adsorption free energy (ΔG_H*) as a key parameter to demonstrate the enhancement in photocatalytic activity of ZnTe/In₂Te₃ compared to a pristine In₂Te₃ monolayer, which is further verified with the explicit water environment. The underlying mechanism is governed by the partial charge distributions of pristine In₂Te₃ and ZnTe/In₂Te₃ heterostructures. The presence of the ZnTe monolayer also altered the bandgap of the In₂Te₃ monolayer from an indirect gap of 1.238 eV to direct gaps of 0.298 eV and 0.181 eV in A- and B-type interfaces of the ZnTe/In₂Te₃ heterostructure, respectively. Calculated optical absorption spectra indicate that ZnTe/In₂Te₃ heterostructures possess better sunlight-harvesting capability compared to monolayer In₂Te₃ near the infrared and visible light regions, implying their potential as an excellent light-absorber. Our predictions provide new guidance for designing 2D III₂–VI₃ heterostructures and expand the applications of these materials in photovoltaics, photocatalysts, and other nanodevices in the future.