PtSe Monolayer: A Highly Efficient Electrocatalyst toward Hydrogen and Oxygen Electrode Reactions.

Electrocatalysts with high activities toward multiple electrode reactions are scarce and therefore highly sought. Here, we investigate the electrocatalytic performance of the two-dimensional (2D) PtSe monolayer toward hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and oxygen reduction reaction (ORR). Our density functional theory calculations show that the PtSe monolayer can serve as a low-Pt-loading trifunctional electrocatalyst with good kinetic and thermal stabilities. Specifically, the HER performance of the PtSe basal plane is predicted to be superior to that of 2D layered Pd or Pt dichalcogenides. Even considering the solvent effect, the catalytic OER performance of the PtSe monolayer is predicted to be comparable to the prevalent OER catalyst-IrO, while the catalytic ORR performance of the PtSe monolayer is even higher than the predominating Pt(111) surface. Overall, the PtSe monolayer can be a promising trifunctional catalyst that exhibits high activities toward all hydrogen and oxygen electrode reactions.