A novel co-catalyst of CoFeOOH for greatly improving the solar water splitting performance over Mo-doped bismuth vanadate

BiVO4 stands out among many semiconductor photoanodes because of its appropriate band gap and high valence band value, and is widely used in the field of photo (electro) catalytic water decomposition. However, its low photocurrent density due to its low carrier mobility and short hole distance hinders its application and development. Therefore, we prepared a new type of CoFeOOH/Mo-BiVO4 photoanode, which increased the carrier density by doping Mo element in BiVO4 and then deposited CoFeOOH co-catalyst on the surface of Mo-BiVO4 in room temperature chemical bath, which accelerated charge separation and inhibited electron-hole recombination as a passivation layer. The results show that the prepared composite photoanode has a high photocurrent density (2.45 mA·cm−2), and the initial potential of oxygen evolution has also shifted negatively by 430 mV. This study provides a new idea for photoanode in doping and co-catalyst.