Exploring monolayer Janus MoSSe as potential gas sensor for Cl2, H2S and SO2

[Display omitted] •The behavior of Mosse doped C atoms was studied.•Adsorption behavior of toxic gases (Cl2, H2S and SO2) on Mosse and C-doped Mosse.•The changes of Mosse before and after doping C atoms were compared.•Analyze the potential of Mosse doped C atoms as gas sensors. Based on first-principles calculations, the adsorption performance of several common poisonous gases (Cl2, H2S, SO2) on the monolayer Janus MoSSe and MoSSe-C are systematically studied. It can be found that Cl2, H2S and SO2 can all be adsorbed on MoSSe and MoSSe-C. The adsorption performance of MoSSe doped with C atom is better, and the binding strengths of gas molecules adsorbed on the S-layer doped with C atom are much stronger than those on Se-layer doped with C atom. The electronic structure of MoSSe-C changes differently under the adsorption of different gas molecules. By calculating the charge density difference and bader charge, the gas adsorption process and charge transfer are revealed. The charge transfer of MoSSe is enhanced by doping C atoms. Cl2, H2S and SO2 are easy to be adsorbed on the monolayer Janus MoSSe doped with C atoms. The monolayer MoSSe doped C atom is a sensitive gas sensor for Cl2, H2S and SO2, and it has potential application as an excellent gas sensor.