Synergistic Activation of Cu2O/WO3/CF Heterostructures via Fe Doping for Efficient Neutral Hydrogen Evolution

Abstract

Electrocatalytic hydrogen production in neutral electrolytes offers a sustainable pathway toward clean hydrogen, but its development is severely constrained by sluggish reaction kinetics and the lack of high-performance non-noble metal electrocatalysts. Herein, efficient hydrogen production is achieved by integrating heterogeneous structure engineering with iron (Fe) doping, fabricating the Fe-Cu2O/WO3/CF material. Results demonstrate that Fe doping and Cu₂O/WO₃ heterojunction construction exert a synergistic effect in optimizing the catalyst's structural and electronic properties: Fe doping induces lattice distortion, generating abundant oxygen vacancies and coordinatively unsaturated active sites, while the Cu₂O/WO₃ heterojunction accelerates interfacial electron transfer. Electrochemical tests show that Fe-Cu₂O/WO₃/CF exhibits excellent HER activity, requiring overpotentials of 95 mV to achieve current densities of 10 mA·cm⁻² and better long-term stability over 40 hours of continuous operation compared to the undoped counterpart. The significantly enhanced HER performance is comprehensively attributed to the combined contributions of optimized electronic structure, enriched active sites and accelerated charge transfer. Specifically, the cooperative interplay of Cu, Fe, and W with distinct d-band center energies, together with Fe doping-induced electronic modulation, upshifts the d-band center, strengthens the interaction between the catalyst surface and reaction intermediates, and induces the formation of different metal-O bonds for directional electron transfer. Meanwhile, Fe2+ (3d6) in tetrahedral (Cu2O phase) and octahedral (WO3 phase) coordination environments optimizes electron transfer and H* adsorption/desorption behavior via π orbital interactions and electron repulsion with O²-. By exploring the synergistic catalytic activation mechanism of heterojunctions and heteroatom doping, this work provides a theoretical foundation for the rational design of high-efficiency non-noble metal oxide catalysts for neutral water electrolysis.