Enhanced hydrogen evolution reaction performance on nickel or cobalt doping engineered MoS₂: A first-principles study

Transition metal dichalcogenide MoS 2 has emerged as a promising non-precious catalyst for hydrogen evolution reaction (HER). However, its performance remains limited by the inertness of the basal plane and insufficient charge transfer. In this study, we systematically investigate the catalytic behaviors of 23 MoS 2 surface models, including pristine and Ni/Co-doped configurations at both basal plane (BP) and edge sites using density functional theory (DFT). The results show that the pristine basal plane is catalytically inactive (∆G H ≈ +1.99 eV), whereas Ni and Co doping effectively activate both basal and edge surfaces. The modified MoS 2 at the S-edge site with 2 Ni atoms substitution (S-edge 2Ni-sub) and with 3 Co atoms substitution (S-edge 3Co-sub) models achieve near-optimal ∆G H values of +0.04 and -0.13 eV, respectively, with strong hydrogen adsorption (E ads = -0.26 and -0.43 eV). Their negative formation energies (E f = -1.68 and -2.14 eV) indicate spontaneous formation and favorable synthetic accessibility. Especially, S-edge 2Ni-sub and S-edge 3Co-sub models are strong candidates for developing efficient and scalable HER electrocatalysts.