Single-atom transition metals doping two-dimensional BXN materials (X = 2, 3, 5) with promising electrocatalytic activity for efficient hydrogen production in the entire pH range

Abstract

Two-dimensional (2D) boron nitrides (BN) have been eagerly and widely used and have tremendous potential in several advanced fields, such as energy harvesting and storage. Due to their significant electronic properties, they are also commonly used as substrates for single-atom catalysts (SACs). Therefore, with the aid of a computer, we designed SACs by doping isolated single atoms of 3d, 4d, and 5d transition metals (TM) on 2D B_XN materials (X = 2, 3, 5). In addition, pH regulation is considered to improve the electrocatalytic hydrogen evolution reaction (HER) activity, and the materials’ effectiveness was investigated theoretically based on density functional theory (DFT) calculations. Our results indicate that the low-cost TM SACs can effectively enhance the HER catalytic performance over a wide range of pH. Among all the SACs studied, Ti-, V-, Y- and Zr@B₅N show excellent catalytic activity at pH = 0, with the Gibbs free energy change (ΔG_H*) of hydrogen adsorption of −0.027, −0.094, 0.073 and −0.040 eV, respectively. We find that Sc- and Y-embedded B₂N, Co-, Fe-, and Mo-embedded B₃N and Co-, Cr-, V-, Ti-, Y-, Zr-, Nb-, Ru-, and Tc-embedded B₅N SACs have excellent catalytic activity in acidic conditions, while Ir-embedded B₅N shows high catalytic activity in alkaline conditions. Interestingly, Ti@B₂N, Mn@B₃N, Fe@B₅N and Mo@B₅N SACs are highly active in either acidic or alkaline environments. Our work opens new avenues for designing cost-effective SACs with wide-pH-range HER performance.