Computational Screening toward Hydrogen Evolution Reaction by the Introduction of Point Defects at the Edges of Group IVA Monochalcogenides: A First-Principles Study.

Abstract

Exploring materials with high hydrogen evolution reaction (HER) performance is of importance for the development of clean hydrogen energy, and the defects on the surfaces of catalysts are essential. In this work, we evaluate the HER performance among group IVA monochalcogenides MXs (M = Ge/Sn, X = S/Se) with M/X point defects on the edges. Compared with basal planes and bare edges, the GeS edge with Ge vacancy (ΔGH* = 0.016 eV), GeSe edge with Se vacancy (ΔGH* = 0.073 eV), and SnSe edge with Sn vacancy (ΔGH* = -0.037 eV) hold the best HER performances, which are comparable to or even better than the value for Pt (-0.07 eV). Furthermore, the relationships between ΔGH* and p-band centers of considered models are summarized. The stability of proposed electrocatalysts are analyzed by vacancy-formation energy and strain engineering. In summary, the HER performance of MXs is greatly improved by introduction of point defects at the edges, which is promising for their use as electrocatalysts for the conversion and storage of energy in the future.