Hierarchical FeCoNi LDH/Cu2S heterojunction arrays for promoting the oxygen evolution reaction

Improvement of catalyst dispersion is an effective strategy for performance enhancement of electrocatalytic oxygen evolution reaction (OER), while the heterogeneous structure can also regulate the electronic structure of the catalyst interface. In this paper, Cu 2 S nanorods were synthesized in situ on copper foam (CF) by alkaline etching and sulfidation, Subsequently, FeCoNi LDH nanosheets were electrodeposited on Cu 2 S nanorods to construct FeCoNi LDH/Cu 2 S heterojunctions. The electrochemical results demonstrate that FeCoNi LDH/Cu 2 S/CF exhibits high efficiency as an alkaline OER electrocatalyst with an overpotential of 211 mV at a current density of 100 mA cm −2 . Furthermore, FeCoNi LDH/Cu 2 S/CF can operate for 30 h and shows good cycling stability. The XPS results indicate that the electrons are transferred from FeCoNi LDH to Cu 2 S. The formation of the FeCoNi LDH/Cu 2 S heterojunction optimizes the interface at the heterojunction, thereby accelerating the electron transfer and optimizing the electronic structure at the interface. The uniform dispersion of FeCoNi LDH provides a high density of active sites and improves the mass transfer ability, thus enhancing the catalytic performance. This experimental strategy presents a generalized approach to improve the efficient electrochemical reaction of layered double hydroxides.