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 Ni 3 N/WO 3 nanosheet arrays of bifunctional catalysts with large specific surface areas loaded on nickel foam (denoted as Ni 3 N/WO 3 /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.