Tailored work function via activated interfacial electron transfer for boosting hydrogen production coupled with electrochemical glycerol oxidation

Abstract

Developing high-performance electrocatalysts for glycerol-assisted water splitting is highly imperative for the applications in energy-saving hydrogen production coupled by valorizing biomass-derived feedstocks. Interface engineering, an effective strategy for tuning the interfacial electronic structures, enables the electrochemical performance improvement, while the precise control on interfacial electron transfer still remains challenging. Herein, Mo incorporation is employed to modulate the interfacial electronic structure of Ni₃S₂/Ni₃P, resulting in an activated electron redistribution with more electrons flowing from Ni₃P to Ni₃S₂. The enhanced electron transfer at the Mo-Ni₃S₂/Ni₃P interface further reduces its work function and positively shifts the d-band center closer to Fermi level, promoting OH⁻ and glycerol adsorption. Compared to Ni₃S₂/Ni₃P, the Mo-Ni₃S₂/Ni₃P exhibits superior electrocatalytic performance for both glycerol oxidation and hydrogen evolution reaction. In simulated alkaline seawater with glycerol, a two-electrode system using Mo-Ni₃S₂/Ni₃P as both the anode and cathode achieves a 390 mV reduction in cell voltage to reach 100 mA cm⁻² compared to water splitting, accompanied by a Faradaic efficiency above 90% for formate. This work will stimulate the further development of work function-guided design of efficient electrocatalysts for sustainable energy conversion.