Electrocatalytic Mechanisms for an Oxygen Evolution Reaction at a Rhombohedral Boron Monosulfide Electrode/Alkaline Medium Interface

Abstract

Rhombohedral boron monosulfide (r-BS) with a layer stacking structure is a promising electrocatalyst for an oxygen evolution reaction (OER) within an alkaline solution. We investigated the catalytic mechanisms at the r-BS electrode/alkaline medium interface for an OER using hybrid solvation theory based on the first-principles method combined with classical solution theory. In this study, we elucidate the activities of the OER at the outermost r-BS sheet with and without various surface defects. The Gibbs free energies along the OER path indicate that the boron vacancies at the first and second layers of the r-BS surface (VB1 and VB2) can promote the OER. However, we found that the VB1 is easily occupied by the oxygen atom during the OER, degrading its electrocatalytic performance. In contrast, VB2 is suitable for the active site of the OER due to its structure stability. Next, we applied a bias voltage with the OER potential to the r-BS electrode. The bias voltage incorporates the positive excess surface charge into pristine r-BS and VB2, which can be understood by the relationship between the OER potential and potentials of zero charge at the r-BS electrode. Because the OH– ions are the starting point of the OER, the positively charged surface is kinetically favorable for the electrocatalyst owing to the attractive interaction with the OH– ions. Finally, we qualitatively discuss the flat-band potential at a semiconductor/alkaline solution interface. It suggests that p-type carrier doping could promote the catalytic performance of r-BS. These results explain the previous measurement of the OER performance with the r-BS-based electrode and provide valuable insights into developing a semiconductor electrode/water interface.

Metal (Ni, Pd, and Pt)-Doped BS Monolayers as a Gas Sensor upon Vented Gases in Lithium-Ion Batteries: A First-Principles Study

“…These data are consistent with those in the literature . The structure of BS belongs to the space group of (164) and is a TMD-like two-dimensional material with a T-phase . The thermal stability of the BS monolayer at 400 and 500 K is confirmed by the ab initio molecular dynamic (AIMD) simulation as shown in Figure S1.…”

“…42 The structure of BS belongs to the space group of P3m1 (164) and is a TMD-like two-dimensional material with a T-phase. 58 The thermal stability of the BS monolayer at 400 and 500 K is confirmed by the ab initio molecular dynamic (AIMD) simulation as shown in Figure S1. The potential energy fluctuates around a certain value, reaching an equilibrium state, and the structure remains intact without obvious deformation, indicating that they have strong thermal stability.…”

Toward Realistic Models of the Electrocatalytic Oxygen Evolution Reaction

“…The authors modeled an Al(111) slab in contact with a NaCl(aq) solvent, varying the applied bias, and obtaining the solvent distribution under grand canonical conditions, therefore describing the variations of the structure of the EDL as the charge of the electrode changes with a varying bias (see Figure ). This approach has been applied to model a variety of electrocatalytic reactions, including the HER, CO 2 reduction and very recently the OER as well.…”