Constructing partially amorphous NiMoB/NiMoO4−x with borate doping and reduction through one step boosting hydrogen evolution

The pursuit of efficient and stable electrochemical catalysts based on transition metals (TMs) for the hydrogen evolution reaction (HER) is of paramount importance. Herein, a novel partially amorphous NiMoB/NiMoO _4−x catalyst with dense nanoparticle assemblies has been prepared with B doping and reduction by one step NaBH ₄ treatment of smooth nanorod-like NiMoO ₄ precursor. Benefiting from the MoNi ₄ alloys partially reduced from NiMoO ₄ precursor, optimized electronic state through B doping and partially amorphous structure, NiMoB/NiMoO _4−x obtained splendid activity for HER with a lower overpotential of 26.2 mV at 10 mA cm ² coupled with a narrow Tafel slope of 66.75 mV dec ¹, in contrast to NiMoO ₄ precursor catalyst (260.24 @10 mA cm ², 149 mV dec ¹) in alkaline solution. Additionally, the self-supported NiMoB/NiMoO _4−x electrode exhibits remarkable stability, maintaining a current density of 50 mA cm ² for a minimum of 40 h attributed to mixed phases of MoNi ₄ and amorphous NiMoO _4−x for accelerating the H ₂ evolution and enhancing water adsorption. This work offers a facile avenue to rationally design high-performance electrocatalysts for enhancing hydrogen evolution with NaBH ₄ accompanying borate doping and reduction.