First-principle calculations on the structure, electronic property and catalytic activity for hydrogen evolution reaction of 2D transition-metal borides

We carried out the first-principle calculations on the structure, thermal stability, magnetic configuration, electronic structure, and electrocatalytic activity for hydrogen evolution reaction (HER) of a class of two-dimensional (2D) transition metal borides (MBenes, where M is Mn, Fe, Cr and Mo; B is boron). The structural and thermal stability of the MBenes was estimated with the cohesive energy, the phonon dispersion curves and the ab initio molecular dynamics (AIMD) simulation calculations. The effects of functionalized groups on the structure of MBenes were also discussed. The magnetic configuration at ground state of both MBenes and their precursors was studied with a sample model. All stable MBenes exhibit metallic transport performance. The valence electrons are generally localized around B–B chains in the unit cell of MBenes, which results in the good stability of MBenes. The free energy of hydrogen adsorption of Mn2B2 is 2 meV for the coverage of 1/8, implying that this 2D boride is a promising candidate for HER application.