Ethanol combustion-assisted fast synthesis of tri-metal oxides with reduced graphene oxide for superior overall water splitting performance

Abstract

Developing rapid and cost-effective methods for preparing electrocatalysts with high efficiency in water splitting is a critical issue in the field of hydrogen production. Herein, a tri-metallic FeCoNi oxide composited with reduced graphene oxide was successfully synthesized via a low-cost one-step solution combustion method. The highly volatile nature of ethanol with its low flash point allows for easy initiation of solution combustion at ambient temperatures using a long-handled lighter, rather than requiring gradual heating to reach ignition temperature. Meanwhile, ethanol provides the source for the growth of reduced graphene oxide. The resulting nanocomposite exhibited a low crystallinity degree and abundant defects, which contributed to its superior bifunctional catalytic performance for the oxygen evolution reaction and the hydrogen evolution reaction in water electrolysis. The optimal electrocatalyst couples possessed a low cell voltage of 1.83 V at a current density of 100 mA cm⁻² in overall water splitting, while also exhibiting long-term stability for at least 170 h under a high current density of 100 mA cm⁻², demonstrating its promise as a substitute for benchmark precious metal-based electrocatalysts used for hydrogen production.