Boosting Charge Transfer of Fe Doping BiVO4/CoOx for Photoelectrochemical Water Splitting

Charge separation efficiency is the main obstacle to limiting the photoelectrochemical (PEC) water-splitting performance of bismuth vanadate (BiVO4) photoanodes. Herein, we report a convenient and efficient strategy for Fe doping into BiVO4 and hybrid CoOx OECs to obtain a Fe-BiVO4/CoOx photoanode. The resulting photoanode exhibits 4.0 mA/cm2 photocurrent density as well as a high charge transfer (74.4%)/separation efficiency (71.2%) at 1.23 V vs reversible hydrogen electrode (RHE) under AM 1.5 G illumination. The synergistic effect of Fe doping and CoOx OEC loading can dramatically boost the electrical conductivity and carrier density of BiVO4. This work provides effective experimental data for improving the PEC performance of BiVO4.