Interlayer Interaction Induced Layer-Dependent Catalytic Activity toward a Hydrogen Evolution Reaction on Two-Dimensional PtSe2

PtSe2, an emerging two-dimensional (2D) transition metal dichalcogenide (TMD), is a promising catalyst for the hydrogen evolution reaction (HER). Herein, we investigated the fundamental mechanism underlying the layer-dependent catalytic activity of PtSe2 via first-principle calculations and demonstrated that interlayer interaction facilitates the catalytic activity by modifying the frontier orbitals of intact basal plane and anion (selenide, Se) vacancy of 2D-PtSe2. The interlayer interaction promotes the catalytic activity by strengthening the bonding between atomic hydrogen and the surface of 2D-PtSe2 through altering the electronic structure of the topmost PtSe2 catalytic layer. We also conducted kinetic simulation to reveal the dominant reaction mechanism underlying the HER on both the basal plane and anion vacancy of different number of layer. The results manifested that the dominant reaction mechanism alters when the number of layer increases from one to two, which is in correlation with the enhancement of the bonding between the hydrogen adatom and PtSe2 catalytic surface from interlayer interaction. Our study demonstrated the synergistic effect of interlayer interaction on HER on 2D-PtSe2 catalyst. ? 2021 American Chemical Society.