Reconstruction of FeNi layered dihydroxides by cobalt doping to improve the electrocatalytic activity of oxygen evolution reaction

The increasing demand of clean energy in modern society calls for the development of efficient and renewable energy sources to reduce the consumption of fossil fuels. Although FeNi layered dihydroxide (FeNi-LDH) is a promising candidate material for oxygen evolution reaction (OER) catalysis, its catalytic performance can be further improved by the increased amounts of active sites, and the enhancement of electrical conductivity and durability. In this case, FeNiCo-LDH with the introduction of cobalt ions to FeNi-LDH can obtain a large active specific surface area by adjusting the electronic structure, and act as the main active substance in the reconstruction process to promote the catalytic performance of OER. Taking advantage of the low cost and easy availability of 304 stainless steel plates, the FeNiCo-LDH nanoplates were uniformly loaded onto the treated 304 plates by a simple two-step method. The as-prepared electrodes show superior OER in 1 M KOH, with 221 and 252 mV overpotentials to attain 10 and 350 mA cm−2 current densities, respectively with an ultra-low Tafel slope of 30.9 mV dec−1. Besides, the electrode also showed good stability in a chronopotential electrolysis at 10 mA cm−2 for 100 h.