Theoretical investigation of structural and electronic properties and water splitting electrocatalytic performance of TM-decorated (TM = Mn, Fe, Co, and Ni) biphenylene monolayers

Searching for novel materials with high efficiency as electrocatalysts in the field of water splitting is one of the most effective approaches to mitigate energy problems. In this study, we present the impact of transition metal (TM = Mn, Fe, Co, and Ni) decoration on the potential of biphenylene (BP) as a water-splitting electrocatalyst using density functional theory. We first present the structural and electronic properties of the TM-decorated BP monolayers. Our results show that TM decoration can influence the frontier orbitals of pristine BP, leading to a reduced energy gap due to charge transfer from TM to the BP surface. In the hydrogen evolution reaction (HER) section, the lowest ΔG for hydrogen adsorption as an intermediate was obtained for Co@BP at 0.26 eV, which is lower than that of pristine BP and graphene reported in previous studies. On the other hand, evaluating the oxygen evolution reaction (OER) electrocatalytic activity of TM-decorated BP monolayers reveals that Mn decoration is an efficient approach, among the selected transition metals, to improve the catalytic performance of BP. Our study introduces a procedure for the rational design of high-performance single-atom catalyst (SAC) materials.