Tuning structure, electronic, and catalytic properties of non-metal atom doped Janus transition metal dichalcogenides for hydrogen evolution

Abstract

The doping of hetero-non-metal atoms into the conventional Transition Metal Dichalcogenide (TMD) monolayer sheets is reported to tune their structural, electronic, magnetic, and catalytic properties. Herein, the physicochemical properties of Janus MoSSe monolayer with the doping of atoms viz. B, C, N, and P are systematically studied using density functional theory. The high binding energies for the doping of non-metal atoms into TMD sheets show energetic stability of the doped Janus sheets. The doping reduces the band gaps as compared to pristine sheet because of the introduction of the bands near the Fermi region. The doping of non-metal atoms also tunes the magnetic properties of Janus nanosheets and broaden up their applications in spintronics. The catalytic activity of the Janus TMDs for Hydrogen Evolution Reaction (HER) is explored which possess inherent strain due to asymmetry. The density functional theoretical studies of the pristine and non-metal atom doped Janus TMDs as HER catalysts are reported in terms of Gibbs free energy which depends on the electronegativity of dopants. The Gibbs free energy of adsorption is tuned to ~0 eV with heteroatom doping. Overall results indicate that the boron doped Janus sheet possesses reduced band gap and tunable work function which contributes to the superior catalytic performance for HER even in the absence of external strain and large basal plane vacancies.