In-situ growth strategy to synthesize porous nano-coral-like structure OER catalyst based on nife foam alloy substrate

Abstract

The preparation of alloy-based catalysts is an effective approach to simplify the catalyst synthesis process for electrocatalysis. The oxygen evolution reaction (OER) is considered a key step in water splitting. By incorporating interface engineering design, electronic state optimization, and heteroatom doping, the electrocatalytic performance can be enhanced. In this study, a simple method was used to activate the NiFe foam (NIF) alloy substrate by acid etching, followed by in-situ S-doping of Cr via a hydrothermal method to synthesize S-Cr0.6@NiFe/NIF catalyst material. Its outstanding porous nanocoral-like structure not only provides abundant active sites but also exhibits superior catalytic water splitting performance, demonstrating superhydrophilic and superaerophobic characteristics. At a current density of 10 mA cm−2, only 262 mV overpotential is required to drive the OER (under basic conditions of 1 M KOH), with a low Tafel slope (71.6 mV dec−1) and a large electrochemical active surface area (ECSA = 85.25 cm2). After 80 hours of OER test, the current density of S-Cr0.6@NiFe/NIF shows negligible change. This study provides an attractive, effective, and feasible method for the in-situ growth design of alloy-based catalysts.