Theoretical understanding of two-dimensional boridenes M4/3B2 for hydrogen evolution

Layered boridenes M4/3B2 have been experimentally validated as a rising two-dimensional (2D) material family. Herein, we investigate nine kinds of 2D M4/3B2 (M = Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W) toward their structural stabilities, electronic properties, and hydrogen evolution performances based on density functional theory (DFT) calculations. Our results show that except for Cr4/3B2, other 2D M4/3B2 materials are dynamically and kinetically stable and are promising for synthesis and application in hydrogen production. Metallic Ti4/3B2 and Ta4/3B2 monolayers are easily oxidized in aqueous environments as ideal platforms with optimal hydrogen adsorption free energies and exchange current densities around the peak of the activity volcano. Our work provides a systematic guideline for the application of the 2D M4/ 3B2 family in HER and reveals their underlying electronic origins.& COPY; 2023 Elsevier Ltd. All rights reserved.

Automated summary

In this study, the structural stabilities, electronic properties, and hydrogen evolution performances of nine kinds of 2D M4/3B2 materials were investigated using density functional theory calculations. The results showed that most of the materials were stable and promising for hydrogen production, except for Cr4/3B2. Monolayers of metallic Ti4/3B2 and Ta4/3B2 were susceptible to oxidation in aqueous environments, but had optimal hydrogen adsorption free energies and exchange current densities.