Water electrolysis represents a promising option for clean hydrogen production, but its overall efficiency is hindered by the sluggish oxygen evolution reaction (OER) with a complex electron transfer process. The construction of heterostructure has emerged as an effective approach to enhance the electrocatalytic performance for OER because of the improvement of exposed active surface and mass/charge transfer. In this work, we report the synthesis of hierarchical nanosheet-structured Ni₂P-NiFe₂O₄ as a robust OER catalyst via an annealing treatment and followed by in-situ phosphating process. The Ni₂P-NiFe₂O₄ electrocatalyst exhibits an overpotential of 305 mV to realize 100 mA cm⁻² in 1.0 M KOH. Density functional theory calculations further confirm that the construction of heterostructure could optimize adsorption energy of oxygen-containing intermediates and reduce energy barrier during the OER process. This work may provide insights into the electrocatalytic activities of non-noble-metal-based catalysts and present an effective method for the preparation of complex structures.

水电解是清洁氢气生产的一种有前途的选择，但其整体效率受到缓慢的析氧反应（OER）和复杂的电子转移过程的阻碍。由于暴露的活性表面和质/电荷转移的改善，异质结构的构建已成为增强 OER 电催化性能的有效方法。在这项工作中，我们报告了通过退火处理和随后的原位磷化工艺合成了分级纳米片结构的Ni ₂ P-NiFe ₂ O ₄作为强大的OER催化剂。Ni ₂ P-NiFe ₂ O ₄电催化剂表现出305 mV的过电势，可在1.0 M KOH中实现100 mA cm ^{-2 。}密度泛函理论计算进一步证实异质结构的构建可以优化含氧中间体的吸附能并降低OER过程中的能垒。这项工作可以为非贵金属基催化剂的电催化活性提供见解，并为制备复杂结构提供有效的方法。