Synergetic effects by Co2+ and PO43- on Mo-doped BiVO4 for an improved photoanodic H2O2 evolution

The efficiency of hydrogen peroxide evolution reaction (H 2 O 2 ER) by photoanodic water oxidation is normally limited by low yield and poor selectivity. In this work, the surfaces of Mo doped BiVO 4 are modified by Co 2+ and PO 4 3- ions (CPMB), which has been used as the photoanode with improved H 2 O 2 yield and selectivity. The optimal evolution rate of the CPMB is ca. 0.23 µmol·min −1 ·cm −2 , corresponding to 2.5 times to the pristine BiVO 4 photoanode, and the faradaic efficiency of CPMB photoanode for H 2 O 2 ER is ca. 26%. In this study, the mechanism for the improved H 2 O 2 evolution performance of CPMB has been investigated, indicating that PO 4 3- ions mainly promote the formation of the •OH by dissociation of H 2 O, while Co 2+ ions accelerate the conversion of the •OH for the subsequent H 2 O 2 evolution. This study offers the strategy for designing an efficient photoelectrochemical system with optimized solar conversion efficiency for H 2 O 2 production.