Generating highly active Ni₁₁(HPO₃)₈(OH)₆/Mn₃O₄ catalyst for electrocatalytic hydrogen evolution reaction by...

The design of electrocatalysts with cost-efficient, highly-efficient and stable for hydrogen evolution reaction (HER) is significant to alleviate energy crisis in the future. Herein, we prepared the Ni₁₁(HPO₃)₈(OH)₃/Mn₃O₄ (named as NiPi/Mn₃O₄) composite with crystalline/amorphous interface by electrochemical activation based on Ni₃P/MnOOH precursor. The precursor was synthesized by two-step method that firstly electrodeposited on nickel foam and then used anodic oxidation under the applied voltage. The XPS analysis manifested that NiPi/Mn₃O₄ had a strong interface coupling between Ni₁₁(HPO₃)₈(OH)₃ and Mn₃O₄ contributed to fast kinetics of hydrogen evolution reaction. The morphology of the nanowires and nanoparticles were provided lager contact area between catalyst and electrolyte. Meanwhile, the obvious interface between crystalline and amorphous also resulted in NiPi/Mn₃O₄ heterostructureted material with faster electron transport and superior stability. Owing to these characteristics, the NiPi/Mn₃O₄ displays amazing HER activity with low overpotential of 84 mV at 100 mA cm^-2 and a long-term stability of over 100 h at 200 mA cm^-2 in 1.0 M NaOH solution. The surprising activity of NiPi/Mn₃O₄ is better than that of most reported catalysts, similar to the state-of-the-art Pt/C.