Effect of intrinsic point defects on the catalytic and electronic properties of Cu2WS4 single layer: Ab initio calculations

The challenges imposed by climate change require the continued improvement and identification of materials for the development of green technologies. Point defect engineering is a promising technology for producing green hydrogen by taking advantage of catalytic hydrogen evolution reactions. In this work, we investigate the role of anionic and cationic vacancy point defects, as well as the nature of the active sites, in the catalytic activation of Cu2WS4 single layers. The stability of the pristine and defective structures of Cu2WS4 has been thoroughly investigated using density-functional theory calculations. A deep analysis of the formation enthalpy indicates that the Cu vacancy is the chemically most favorable vacancy. However, the calculated adsorption energy indicates that the presence of such vacancies slightly enhances the hydrogen evolution reaction. In contrast, the formation of an S vacancy considerably magnifies the same reaction in Cu2WS4 single layers.

Automated summary

The challenges brought by climate change call for the improvement and discovery of materials for green technology development. This study investigates the role of anionic and cationic vacancy defects and the nature of active sites in the catalytic activation of Cu2WS4 single layers. By using density functional theory calculations, the stability of pristine and defective structures of Cu2WS4 has been thoroughly studied. The formation enthalpy analysis indicates that Cu vacancy is the most favorable chemically, while the adsorption energy shows that the presence of such vacancies slightly enhances the hydrogen evolution reaction. On the other hand, the formation of an S vacancy considerably magnifies the same reaction in Cu2WS4 single layers.