Experimental and DFT studies of flower-like Ni-doped Mo2C on carbon fiber paper: A highly efficient and robust HER electrocatalyst modulated by Ni(NO3)2 concentration

Abstract Developing highly efficient and stable non-precious metal catalysts for water splitting is urgently required. In this work, we report a facile one-step molten salt method the preparation of self-supporting Ni-doped Mo 2 C on carbon fiber paper (Ni-Mo CB /CFP) hydrogen evolution reaction (HER). The effects nickel nitrate concentration phase composition, morphology, electrocatalytic HER performance C@CFP electrocatalysts was investigated. With continuous increase Ni(NO 3 ) concentration, morphology gradually changes from granular to flower-like, providing larger specific surface area more active sites. Doping (Ni) into crystal lattice largely reduces impedance enhances their activity. as-developed C-3 M /CFP electrocatalyst exhibits high catalytic activity with small overpotential 56 mV at current density 10 mA·cm −2 . This catalyst has fast kinetics, as demonstrated by very Tafel slope 27.4 mV·dec −1 , persistent long-term stability. A further higher Ni had an adverse effect performance. Density functional theory (DFT) calculations verified experimental results. doping could reduce binding energy Mo-H, facilitating desorption adsorbed (H ads surface, thereby improving intrinsic C-based catalysts. Nevertheless, excessive would inhibit electrocatalysts. work not only provides simple strategy activity, but also unveils influence mechanism theoretical perspective.