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 for the preparation of self-supporting Ni-doped Mo2C on carbon fiber paper(Ni-Mo2CCB/CFP)for hydrogen evolution reaction(HER).The effects of nickel nitrate concentration on the phase composition,morphology,and electrocatalytic HER performance of Ni-doped Mo2C@CFP electrocatalysts was investigated.With the continuous increase of Ni(NO3)2 concentration,the morphology of Mo2C gradually changes from granular to flower-like,providing larger specific surface area and more active sites.Doping nickel(Ni)into the crystal lattice of Mo2C largely reduces the impedance of the electrocatalysts and enhances their electrocatalytic activity.The as-developed Mo2C-3 M Ni(NO3)2/CFP electrocatalyst exhibits high catalytic activity with a small overpotential of 56 mV at a current density of 10 mA·cm-2.This catalyst has a fast HER kinetics,as demonstrated by a very small Tafel slope of 27.4 mV·dec-1,and persistent long-term stability.A further higher Ni concentration had an adverse effect on the electrocatalytic performance.Density functional theory(DFT)calculations further verified the experimental results.Ni doping could reduce the binding energy of Mo-H,facilitating the desorption of the adsorbed hydrogen(Hads)on the surface,thereby improving the intrinsic catalytic activity of Ni-doped Mo2C-based catalysts.Nevertheless,excessive Ni doping would inhibit the catalytic activity of the electrocatalysts.This work not only provides a simple strategy for the facile preparation of non-precious metal electrocatalysts with high catalytic activity,but also unveils the influence mechanism of the Ni doping concentration on the HER performance of the electrocatalysts from the theoretical perspective.

Lei ZHANG;Zhihui HU;Juntong HUANG;Zhi CHEN;Xibao LI;Zhijun FENG;Huiyong YANG;Saifang HUANG;Ruiying LUO

School of Materials Science and Engineering,Nanchang Hangkong University,Nanchang 330063,China;School of Materials Science and Engineering,Jiangsu University of Science and Technology,Zhenjiang 212003,China;Research Institute for Frontier Science,Beihang University,Beijing 100191,China

先进陶瓷（英文版）

[1]Lei ZHANG;Zhihui HU;Juntong HUANG;Zhi CHEN;Xibao LI;Zhijun FENG;Huiyong YANG;Saifang HUANG;Ruiying LUO-.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)[J].先进陶瓷（英文版）,2022(08):1294-1306

Mo2CCB,Hads

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