Abstract
Hydrogen as fuel has gained large interest nowadays as a green energy source. Single-atom catalysis has emerged as a promising strategy for producing hydrogen. Herein, we investigated the late first row transition metals (TM = Co, Cu, Zn, Ni and Fe) adsorbed on eight-membered boron ring (TM@B8) as potential single-atom catalysts (SAC) towards hydrogen evolution reaction (HER) as well as oxygen evolution reaction (OER), aiming to identify less expensive electrocatalysts with high efficiency. Various properties including interaction energy (E (int)), energies of frontier molecular orbitals (FMOs), natural bonding orbital (NBO) charges, total density of state (TDOS) spectra and non-covalent interaction (NCI) analyses of considered complexes are explored. These findings demonstrated that both pure TM@B8 and hydrogen-adsorbed TM@B8 complexes have both structural and electronic stability. The Co@B8 complex demonstrated a favorable Gibbs free energy of 0.16 eV toward HER under gaseous conditions. Fe@B8 showed better OER activity having overall η (OER) of 1.14 eV. These outcomes show the promising potential of TM@B catalysts for both HER and OER processes.