The effect of Mo doping on the charge separation dynamics and photocurrent performance of BiVO photoanodes.

Doping with electron-rich elements in BiVO photoanodes has been demonstrated as a desirable approach for improving their carrier mobility and charge separation efficiency. However, the effect of doping and dopant concentration on the carrier dynamics and photoelectrochemical performance remains unclear. In this work, we examined the effects of Mo doping on the charge separation dynamics and photocurrent performance in BiVO photoanodes. We show that the photocurrent of BiVO photoanodes increases with increasing concentration of the Mo dopant, which can be attributed to both the improved carrier mobility resulting from increased electron density and charge separation efficiency due to the diminishing of trap states upon Mo doping. The effect of doping on the electronic structure, carrier dynamics and photocurrent performance of BiVO photoanodes resulting from W and Mo dopants was also compared and discussed in this study. The knowledge gained from this work will provide important insights into the optimization of the carrier mobility and charge separation efficiency of BiVO photoanodes by controlling the dopants and their concentrations.