Defect engineering strategies in monolayer VSe₂ for enhanced hydrogen evolution reaction: a computational study

Defect engineering is a powerful strategy for enhancing the catalytic properties of monolayer VSe₂. In this work, we used density functional theory (DFT) to investigate the impact of point defects and hydrogen adsorption sites on the hydrogen evolution reaction (HER) activity of VSe₂. We analyzed the formation energies and hydrogen adsorption behavior of single and double vacancies in VSe₂. The results show that V vacancy defect (D2), consecutive V-Se double vacancy defect (D3), and separate V-Se double defect (D4) exhibit the enhanced HER activity with Gibbs free energies (ΔG_H* = 0.04 eV, 0.04 eV and 0.06 eV, respectively) even surpassing that of platinum (ΔG_H* = − 0.1 eV). This study highlights the potential of defect-engineered VSe₂ for efficient hydrogen evolution.