NiFe<sub>2</sub>O<sub>4</sub>/NiFeP Heterostructure Grown on Nickel Foam as an Efficient Electrocatalyst for Water Oxidation
Xin Li, Wei‐Qing Huang, Lixin Xia, Yuanyuan Li, Huawei Zhang, Shao‐Fang Ma, Yimeng Wang, Xinjun Wang, Gui‐Fang Huang
Abstract
Abstract The rational construction of cost‐effective electrocatalysts for high‐performance water oxidation is a huge challenge. In this work, heterogeneous NiFe‐based oxide/phosphide (NiFe 2 O 4 /NiFeP) nanoplates are synthesized on Ni foam using a selective phosphorization process with double crucibles in a muffle furnace. The constructed NiFe 2 O 4 /NiFeP heterostructure shows superior catalytic performance for the oxygen evolution reaction (OER). Impressively, the optimal NiFe 2 O 4 /NiFeP heterostructure demonstrates a low overpotential of 191 mV to afford an anodic current density of 10 mA cm −2 in 1 M KOH, which is better than most of reported OER electrocatalysts. The superior OER activity can be ascribed to the well‐configured 3D network structure composed of vertically interlaced nanoplates to provide more exposed active sites and an optimal electronic structure that arises from a synergistic effect between NiFe 2 O 4 and NiFeP to facilitate charge separation and reduce the energy barrier. This selective phosphorization strategy enables rational construction of oxides/phosphides heterostructures with superior OER performance.