Electrocatalytic activity of MoSi2N4 monolayers decorated with single transition metal atoms: a computational study

Two-dimensional (2D) MoSi2N4is a newly created material that has superstability and ultrahigh carrier mobility. Besides, the hydrogen evolution reaction activity was proved excellent by doping transition metal (TM) atoms and introducing N vacancies. But, the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) of 2D MoSi2N4is unclear even. We have explored the electrocatalytic properties (OER/ORR) of MoSi2N4by introducing Si vacancies and attaching various TM atoms. The structure and optoelectronic characteristics of MoSi2N4have been researched in detail using density functional theory calculations. By analyzing the density of states, the free energy change diagram and contour maps of TM@VSi-MoSiN, the results show that Co@VSi-MoSiN has the lowest OER overpotential (0.53 V) among all samples. Additionally, the d-band center is used to explain the electrocatalytic origin of the OER and ORR of TM@VSi-MoSiN. Our discoveries expand the 2D TM@VSi-MoSiN applicability in the realm of catalysis.