Electrochemically Reconstructed Cu‐FeOOH/Fe<sub>3</sub>O<sub>4</sub> Catalyst for Efficient Hydrogen Evolution in Alkaline Media
Chenfan Yang, Wenda Zhong, Ke Shen, Qin Zhang, Rong Zhao, Hui Xiang, Jing Wu, Xuanke Li, Nianjun Yang
Abstract
Abstract Surface self‐reconstruction via incorporating an amorphous structure on the surface of a catalyst can induce abundant defects and unsaturated sites for enhanced hydrogen evolution reaction (HER) activity. Herein, an electrochemical activation method is proposed to reconstruct the surface of a Cu‐Fe 3 O 4 catalyst. Following a “dissolution–redeposition” path, the defective FeOOH is formed under potential stimulation on the surface of the Cu‐Fe 3 O 4 precursor during the electrochemical activation process. This Cu‐FeOOH/Fe 3 O 4 catalyst exhibits excellent stability as well as extremely low overpotential toward the alkaline HER (e.g., 129 and 285 mV at the large current densities of − 100 and 500 mA cm −2 , respectively), much superior to the Pt/C catalyst. The experimental and density functional theory calculation results demonstrate that the Cu‐FeOOH/Fe 3 O 4 catalyst has abundant oxygen vacancies, featuring optimized surface chemical composition and electronic structure for improving the active sites and intrinsic activity. Introducing defective FeOOH on the surface of a Cu‐Fe 3 O 4 catalyst by means of an electrochemical activation method decreases the energy barrier of both H 2 O dissociation and H 2 generation. Such a surface self‐reconstruction strategy provides a new avenue toward the production of efficient non‐noble metal catalysts for the HER.