Heterointerface‐Rich Ni₃N/WO₃ Hierarchical Nanoarrays for Efficient Glycerol Oxidation‐Assisted Alkaline Hydrogen Evolution

Abstract

Glycerol oxidation‐assisted water electrolysis has emerged as a cost‐effective way of co‐producing green hydrogen and HCOOH. Still, preparing highly selective and stable nickel‐based metal electrocatalysts remains a challenge. Herein, heterostructure Ni3N/WO3 nanosheet arrays of bifunctional catalysts with large specific surface areas loaded on nickel foam (denoted as Ni3N/WO3/NF) were synthesized. This catalyst was for glycerol oxidation reaction (GOR) and hydrogen evolution reaction (HER) with excellent catalytic performance, a voltage saving of 267 mV compared to oxygen evolution reaction (OER), and a HER overpotential of 104 mV at 100 mA cm‐2. The cell voltage in the assembled GOR // HER hybrid electrolysis system reaches 100 mA cm‐2 at 1.50 V, 296 mV lower than the potential required for overall water splitting. This work demonstrates that replacing GOR with OER using a cost‐effective and highly active Ni‐based bifunctional electrocatalyst can make hybrid water electrolysis an energy‐efficient, sustainable, and green strategy for hydrogen production.