Interface Engineering of Ni<sub>3</sub>Fe and FeV<sub>2</sub>O<sub>4</sub> Coupling with Carbon-Coated Mesoporous Nanosheets for Boosting Overall Water Splitting at 1500 mA cm<sup>–2</sup>
Hao Zhang, Guangfu Qian, Tianqi Yu, Jinli Chen, Lin Luo, Shibin Yin
Abstract
Constructing a heterojunction is vital to increase the performance of non-noble metal catalysts for overall water splitting (OWS) at large current density. Herein, we synthesize a Ni3Fe/FeV2O4 heterojunction catalyst with a carbon-encapsulated mesoporous nanosheet structure self-supported on nickel foam (NF) by hydrothermal and annealing processes. The obtained catalyst inherits the merits of Ni3Fe and FeV2O4, and the heterostructure can efficiently enhance the catalytic activity. Besides, the carbon layer combined with mesoporous nanosheets could provide more active sites to improve the performance. Low overpotentials (220/350 and 44/366 mV at ±10/±1500 mA cm–2) are required for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). For OWS, a potential of 1.51 V is required to reach 10 mA cm–2 and is maintained at 1500 mA cm–2 for 100 h in 6.0 M KOH at 60 °C. This work thus introduces a valuable and durable catalyst for OWS at large current density.