Electronic structure and hydrogen evolution reaction in Janus monolayer MoSSe regulated by strain engineering

Recently, the Janus monolayer with structural symmetry-breaking has been synthesized, which displays many special physical and chemical properties. However, the regulation about its electronic structure as an important application in hydrogen evolution reaction (HER) has not been explored so far. Herein, the H and T phased MoSSe monolayer is considered as model to discuss the contribution of structural deformation to electronic structure and Gibbs free energies, searching for a potential application in HER. The calculations disclose that tensile strain not only efficiently reduces the band gap of MoSSe but also makes the Gibbs free energy of adsorbed hydrogen close to zero. Our calculations provide a new insight into regulating material's electronic structure and HER performance.