First principles investigation of non-metallic regulated single-atom Mo/C electrocatalyst: Superior performance for hydrogen evolution reactions

High efficiency electrocatalysts play a crucial role for clean and green hydrogen energy. Here, the catalytic performance of Mo atom anchored on graphene surfaces regulated by non-metal (X = B, P, S, N) for water splitting and hydrogen evolution reactions (HER) is investigated by the first principles of density functional theory (DFT). The structural and electronical properties calculation demonstrated that the stable Mo@X 4 C systems can be created where covalent bond is formed between Mo and X atoms. It is also found that the adsorption ability of H 2 O on Mo@X 4 C (X = B, P, S, N) surfaces are directly related to d-band centers of Mo atoms. In water splitting process, the splitting reaction energy barrier of H 2 O has the trend of Mo@B 4 C < Mo@P 4 C < Mo@S 4 C < Mo@N 4 C. Significant orbital hybridization coupling and charge transfer occur between adsorbed H 2 O molecule and Mo@X 4 C surfaces. Specifically, the Mo@B 4 C catalyst is predicted to exhibit not only promising splitting activity, but also superior high performance for HER . And the value of Δ G H* is 0.04 eV, which is very close to ideal zero. Thus, it can be recommended as a stable, low-cost and superior performance catalyst for hydrogen production . Lower Bader charge of Mo and larger work function both facilitate the release of hydrogen. It reveals that non-metallic coordination regulation serves as promising way to design high performance electrocatalysts for water splitting and hydrogen production .