Fe-doped BiVO4 nanorods as photoanode for high-performance solar-driven H2O2 photoelectrochemical cells

This study innovatively develops monoclinic-phase Fe-doped BiVO 4 nanorods (Fe-BiVO 4 ) via hydrothermal synthesis as a high-efficiency photoanode catalyst for H 2 O 2 photoelectrochemical cells. By optimizing Fe doping (5 wt%), the material achieves a remarkable red-shift in light absorption and reduced bandgap, significantly enhancing visible-light utilization and charge separation. The 5 % Fe-BiVO 4 -based photoelectrochemical cell demonstrates a peak power density of 2.16 mW·cm −2 under AM 1.5G illumination, along with the calculated solar-to-electricity conversion efficiency (SECE) of 2.10 %, which is approximately 2.7 times higher than that of pure BiVO 4 -based photoelectrochemical cell. Crucially, Fe doping modulates the band structure, raising the conduction band to +0.13 V vs. RHE, which suppresses H 2 evolution and directs photogenerated electrons toward efficient H 2 O 2 reduction at the cathode side. The cell exhibits exceptional energy storage capability, delivering a specific capacitance of 31,622 mF·cm −2 (3.26 times enhancement in comparison to BiVO 4 ) after 3 h illumination and remaining 61.3 % specific capacitance after continuous 12 h operation. Combined with robust cyclability and cost-effective fabrication, this work provides a scalable strategy for solar-to-chemical-to-electrical energy conversion.