Design of Ni/Ni4Mo Heterointerface for Highly Enhanced Glycerol-Assisted Hydrogen Production at Large Current Density

Incorporating catalytic metals with alloy can significantly facilitate electrocatalysis of hydrogen evolution reaction (HER) through a synergistic effect. However, constructing an effective metal-alloy heterointerface remains a challenge. In this study, we synthesize a Ni/Ni4Mo catalyst on Ni foam (NF) through a straightforward two-step electrodeposition process. Initially, Ni4Mo is obtained using a constant potential deposition method. Then the incorporation of Ni leads to the formation of Ni/Ni4Mo heterointerface, increasing interfacial activity and exposing more active sites, thereby enhancing the electrocatalytic performance. The Ni/Ni4Mo@NF catalyst exhibits outstanding HER performance with low overpotentials of only 148 mV at 500 mA cm−2 and 24 mV at 100 mA cm−2 in 1 M KOH. Furthermore, in a combined glycerol oxidation reaction (GOR) and HER system, the Ni/Ni4Mo@NF||Ni/Ni4Mo@NF requires only 1.41 V to achieve a current density of 50 mA cm−2, a 260 mV reduction compared to conventional overall-water splitting. The Ni/Ni4Mo catalyst also demonstrates good long-term stability. This work provides key insights into designing high-performance metal-alloy heterointerface catalysts for energy-efficient hydrogen production.