Self-supported amorphous high entropy alloy/crystalline Ni2P heterostructure for water oxidation under alkaline condition

High entropy alloys (HEAs) have emerged as a promising electrocatalyst, owing to its high entropy configuration, rich defects, and strong synergism. In this study, a solvothermal method was used to prepare amorphous transition metal-based HEA. Subsequently, HEA/Ni2P heterostructures were formed on the surface of HEA through an electrodeposition-assisted pyrolysis strategy. The resulting self-supporting HEA/Ni2P heterojunction electrode exhibited a low overpotential of 255 mV at 10 mA·cm−2, a small Tafel slope of 56.86 mV·dec−1, and a long-term durability of 24 h in 1.0 M KOH. The formation of the heterojunction could adjust the electronic structure of the amorphous HEA, improve the electron transfer between HEA and Ni2P, thus enhance the OER activity of the composite. This study not only presents a novel strategy for constructing electrocatalysts based on HEA but also demonstrates the significant application of HEA in the field of electrocatalysis.