Heterostructured Ni₃N-NiMoN Nanowires as Bifunctional Electrocatalysts for Hydrogen Evolution and 5-Hydroxymethylfurfural Oxidation

Affected by the slow kinetic oxygen evolution reaction (OER), the cell voltage of water splitting is usually beyond 1.5 V, causing high energy consumption to produce hydrogen. Herein, heterostructural Ni₃N-NiMoN nanowires supported on carbon cloth (Ni₃N-NiMoN/CC) are successfully fabricated, and they can act as bifunctional electrocatalysts, exhibiting a low overpotential of 74 mV at 100 mA cm^-2for hydrogen evolution reaction (HER) and a low potential of 1.39 V at 50 mA cm^-2for 5-hydroxymethylfurfural oxidation reaction (HMFOR), respectively. The HMFOR//HER device constructed by Ni₃N-NiMoN/CC achieves a very low cell voltage of ∼1.29 V at 10 mA cm^-2, which is 0.32 V lower than that of the OER//HER device. Specially, a value-added product of 2,5-furandicarboxylic acid is obtained. Additionally, density functional theory calculations are carried out. This work provides a promising strategy to further reduce the cell voltage to generate hydrogen by replacing OER with biomass oxidation.