Vanadium doping-induced electronic modulation in vanadium oxide/copper nanoparticles embedded in nitrogen-doped...

Developing earth-abundant, bifunctional electrocatalysts that simultaneously accelerate the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is essential for large-scale alkaline water electrolysis. Herein, a sustainable sol-gel-assisted pyrolysis strategy is reported to fabricate vanadium oxide/copper nanoparticles uniformly embedded in nitrogen-doped carbon (V₂O₃/Cu@NC). Comprehensive characterization reveals that vanadium doping introduces abundant oxygen vacancies, enriches pyridinic-N content, and modulates the electronic structure through Cu-V charge redistribution, where electron transfer from V to Cu optimizes the electronic environment and thereby enhances charge/mass transfer. The optimized V₂O₃/Cu@NC-1.0 composite exhibits overpotentials of 50 mV for the HER and 313 mV for the OER at 10 mA cm^-2 in 1 M KOH. In a two-electrode electrolyzer configuration, the V₂O₃/Cu@NC-1.0||V₂O₃/Cu@NC-1.0 cell requires only 1.65 V to achieve 10 mA cm^-2 and demonstrates robust stability over 100 h at 50 mA cm^-2. This work presents a scalable and sustainable approach for designing high-performance bifunctional electrocatalysts, highlighting the critical role of electronic modulation in advancing transition-metal-based materials for efficient water splitting.