Three-dimensional porous nanosheets array FeVO4/NF-a catalyst for oxygen evolution reaction at industrially relevant current densities

Abstract

Electrochemical water splitting is a vital means of producing hydrogen in the future. However, the sluggish kinetics of the oxygen evolution reaction (OER) at the anode of the water electrolysis limits its efficiency. Moreover, high current density (≥500 mA/cm2) hydrogen production that meets industrial requirements and remains relatively stability is the trend currently. Herein, we reported a three-dimensional porous nanosheets array electrocatalyst FeVO4/NF-a synthesized by electrochemical activation and hydrothermal method. The developed FeVO4/NF-a electrode represents excellent OER performance at high current densities, which allows a low overpotential of 376 mV to achieve 1000 mA/cm2 and keeps its durability for 50 h. Structural characterizations and electrochemical analyses show that the NF surface was converted to the active phase NiOOH for OER during electrochemical activation. The introduction of Fe3+ and V3+ changes the electron distribution of elements on the catalyst surface and optimizes its intrinsic activity. Additionally, the three-dimensional network structure of FeVO4/NF-a facilitates the gas diffusion and the contact between the catalyst with the electrolyte. This work will provide new ideas for hydrogen production from water electrolysis toward high current density.