Activating PtSe2 Monolayer for Hydrogen Evolution Reaction by Defect Engineering and Pd Doping

Abstract Platinum diselenide (PtSe2) has been successfully fabricated with a hope of catalytic applications. However, the active sites of pristine PtSe2 are only located at the edges while the sites in basal plane are largely inactive. To change such situation, in this study we introduce Pd dopant and vacancies to activate the basal plane for hydrogen evolution reaction (HER). Based on systematic density functional theory calculations, we find that Pd doping reduces the band gap and enhances the catalytic ability, and the divacancy sites (VSe2 and VPt2) in pristine PtSe2 monolayer and the monovacancy sites (VSe, VPd) as well as the divacancy sites (VPt2, VPdPt) in PdPtSe4 monolayer significantly improve the catalytic activities comparable to that of Pt(1 1 1). A band-center model is applied to better understand the difference in HER activities, where the chemical bond energies of H (ΔG1) show an approximately linear relationship with the energy of d/p level of Pt/Se. The strategy proposed here would be applicable to other two-dimensional materials.