Dual‐Functional AgFe–B Electrocatalyst Simultaneously Achieves Charge Separation and Reduced Energy Barrier for Water Oxidation in BiVO ₄ Photoanodes

This study focuses on enhancing the performance of bismuth vanadate (BiVO 4 ) by integrating electrocatalysts to achieve breakthroughs in photoelectrochemical (PEC) water splitting, a promising approach for sustainable hydrogen production where efficient and stable photoelectrode materials are critical for high solar‐to‐hydrogen conversion efficiency. Herein, AgFe–B‐modified Mo:BiVO 4 (AgFe‐B/Mo:BiVO 4 ) photoanodes were successfully fabricated using an immersion deposition method. At 1.23 V versus reversible hydrogen electrode, the AgFe–B/Mo:BiVO 4 photoanode exhibited a remarkable photocurrent enhancement from 0.73 to 2.45 mA cm −2 , representing a 3.36‐fold increase. Additionally, the modified photoanode showed an increased open‐circuit voltage and improved charge separation efficiency. Reduced charge transfer resistance and enhanced charge injection efficiency were also demonstrated. Steady‐state and transient fluorescence spectroscopy further confirmed the superior carrier separation capability imparted by the AgFe electrocatalyst to Mo:BiVO 4 . Collectively, these results underscore the positive impact of silver–iron‐based electrocatalysts on the PEC performance of Mo:BiVO 4 , offering an effective strategy for optimizing PEC water splitting systems.