Electrocatalytic activity of MoSi₂N₄monolayers 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@V_Si-MoSiN, the results show that Co@V_Si-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@V_Si-MoSiN. Our discoveries expand the 2D TM@V_Si-MoSiN applicability in the realm of catalysis.