Interfacial Synergy of Ni3S2–MoS2 Heterojunction for Electrocatalytic Oxidation of Biomass Molecules

The electrocatalytic oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) offers a sustainable route for biomass valorization, yet the development of high-performance non-noble-metal electrocatalysts remains challenging. Herein, a Ni3S2–MoS2 heterojunction catalyst with a three-dimensional porous flower-like architecture is successfully grown on nickel foam via a one-step hydrothermal method. The catalyst delivers a high HMF oxidation performance, achieving approximately 100% HMF conversion, FDCA yield, and Faradaic efficiency at 1.43 V vs RHE. XPS analysis reveals an increase in the Ni 2p binding energy and the Ni3+ proportion after the reaction, indicating the formation of NiOOH active species. Electrochemical impedance spectroscopy and open-circuit potential measurements suggest that the dense heterointerface facilitates charge transfer and enhances HMF adsorption, thereby optimizing the electronic structure and boosting the catalytic performance. Furthermore, the catalyst exhibits excellent substrate versatility toward various biomass-derived polyols (glycerol, 1,2-propanediol, and ethylene glycol) and remarkable stability in a membrane electrode assembly, maintaining stable operation for 100 h at 100 mA cm–2. This work demonstrates that interfacial synergy in Ni3S2–MoS2 heterojunctions provides an effective strategy for tuning HMF electrooxidation, paving the way for efficient and selective biomass valorization.