Enhancement of electrocatalytic performance of Janus In2SSe monolayer for oxygen evolution reaction by the introduction of N

Non-metallic atom doping as efficient oxygen evolution reaction (OER) electrocatalysts has attracted much interest. In this work, the feasibility of N doped Janus In2SSe monolayers as an OER electrocatalyst is systematically investigated using first-principles calculations. The results suggest that the N substitution with high spin states for the S/Se atom in the Janus In2SSe monolayer can effectively enhance the electrocatalytic reactivity of adsorbed intermediates. The NS-In2SSe monolayer exhibit outstanding OER catalytic performance with small overpotential of 0.687 V. Moreover, the strong atomic interactions between the N dopant and intermediates can be contributed to the hybridization between the O- and N-p orbitals. Through the analysis of crystal orbital Hamilton population (COHP), the adsorption strength of OH species on the NS-In2SSe monolayer is stronger than that on the NSe-InSe monolayer, leading that the NS-In2SSe monolayer possesses a higher OER electrocatalytic activity. The fourth electron reaction step becomes exothermic when the real solution environment is considered, meaning that the desorption of O2 becomes easier under aqueous solution conditions. This work demonstrates the possibility of N doped Janus In2SSe monolayer as electrocatalyst and also offers new insights into designing SACs constructed by non-metal atoms.