Built-in electric field driven electron-proton transfer in CeO 2 /β-Ni(OH) 2 heterojunction for efficient biomass electrocatalysis

Interfacial engineering has emerged as a critical approach for tailoring catalytic systems through precise regulation of charge transfer and surface properties. However, construction of well-defined and functionally coupled heterointerfaces to enhance electron transport efficiency, as well as the in-depth understanding of intrinsic relationship between interfacial coupling effects and electrocatalytic performance, remain significant challenges. In this work, a tightly coupled CeO2/β-Ni(OH)2 heterojunction catalyst was constructed via in-situ electrodeposition method, enabling efficient electrocatalytic oxidation of 5-hydroxymethylfurfural (HMF). CeO2 modulated the electronic structure and surface properties of β-Ni(OH)2 through a synergistic coupling mechanism between Ni3+-O moieties and Ce3+ species. The resulting heterojunction structure exhibited a pronounced built-in electric field, accelerating NiOOH formation and selective adsorption of substrate molecules. Meanwhile, the incorporation of CeO2 significantly improved the hydrophilicity and reaction kinetics. This study offers new insights into the structure-activity relationship of interfacial charge transfer in heterostructured catalysts and provides guidance for future electrocatalyst design.