Evaluating nonmetal atom doping in two-dimensional VSe2 monolayers for hydrogen and oxygen electrocatalysis

The electrocatalytic performance of VSe2 doped with nonmetals (NMs) was studied using density functional theory, in which NM atoms (C, N, O, P, S, F, Cl, Br, and I) replaced Se or V (denoted as NM@Se or NM@V). Notably, P@V and Br@V monolayers exhibit high catalytic hydrogen evolution reaction activity with the lowest Delta G(H)* = 0.08 eV and -0.03 eV, respectively, surpassing Pt (Delta G(H)* = -0.1 eV). By applying the scaling relationship of Delta G(H)* of H*, which is an intermediate for each volcano, the exchange current density diagrams are established. Based on thermodynamic analysis, P@V and Br@V monolayers produce exchange currents of about -1.42 and -0.70i(0)/(A cm(-2)), respectively. The oxygen evolution reaction activity of the I@Se monolayer (eta(OER) = 0.95 V) is the best among all the monolayers. Among the oxygen reduction reaction catalysts, the O@Se monolayer displays high activity with a low eta(ORR) (0.82 V), which is even better than that of binary Pt and Pd alloys (0.9-0.87 V).