Simultaneous hydrogen evolution and ethanol oxidation in alkaline medium via a self-supported bifunctional electrocatalyst of Ni-Fe phosphide/Ni foam

Abstract

Hydrogen (H2) generated via water electrolysis exhibits great potential in addressing the urgent environmental and energy issues. Nevertheless, this approach is immensely handicapped by the tardy oxygen evolution reaction (OER). The ethanol oxidation reaction (EOR) can feasibly substitute the OER for hydrogen generation with less power expending on account of the more beneficial thermodynamics and kinetics. Herein, the hierarchical nickel–iron phosphide (Ni-Fe-P) nanosheet directly grown on Ni foam (NF) is proposed as a high-efficiency self-supported bifunctional electrocatalyst. Integrating the advantages of the unique architecture and the composition, the Ni-Fe-P/NF electrode displays highly alluring electrocatalytic activity and stability toward EOR as well as hydrogen evolution reaction (HER). The as-assembled Ni-Fe-P/NF//Ni-Fe-P/NF hybrid ethanol–water electrolyser only requires 1.53 V to supply 10 mA cm−2, outperforming the sole water splitting (1.66 V). Noteworthily, the liquid product of electrolysis is more meritorious than the raw material, highlighting that the hybrid ethanol–water electrolyser we elaborated possesses prodigious potentiality for application in energy-saving H2 generation and the oxidation of ethanol into acetic acid. This work may provide an innovative strategy in designing and developing other high-efficiency organic molecule electrocatalysts and related energy-saving H2 production applications in the future.