Electrocatalytic and photocatalytic performance of noble metal doped monolayer MoS₂ in the hydrogen evolution reaction: A first principles study

To maximize the catalytic performance of MoS₂ in the hydrogen evolution reaction, we investigate the electrocatalytic and photocatalytic performance of monolayer MoS₂ doped with noble metal (Ag, Au, Cu, Pd, and Pt) using first principles calculation combined with the climbing image nudged elastic band method. We find the band gap of the monolayer MoS₂ is reduced significantly by the noble metal doping, which is unfavorable to improving its photocatalytic performance. The optical absorption coefficient shows that the doping does not increase the ability of the monolayer MoS₂ to absorb visible light. The monolayer MoS₂ doped with the noble metal is not a potential photocatalyst for the hydrogen evolution reaction because the band edge position of the conduction band minimum is lower than −4.44 eV, the reduction potential of H⁺/H₂. Fortunately, the band gap reduction increases the electron transport performance of the monolayer MoS₂, and the activation energy of water splitting is greatly reduced by the noble metal doping, especially the Pt doping. On the whole, noble metal doping can enhance the electrocatalytic performance of the monolayer MoS₂.