Charge Carrier Dynamics on Mesoporous WO₃ during Water Splitting

Abstract

Transient absorption spectroscopy (TAS) has been employed to identify the spectra of photogenerated electrons and holes on WO3. WO3 is a widely studied photoanode for the oxidation of water, and by measuring the decay of photoholes on the milliseconds to seconds time scale in the presence of an electron scavenger, we provide a lower limit for the required lifetime of holes for water oxidation on WO3. The rate of electron/hole recombination on WO3 has also been examined at a range of excitation intensities and is found to be nonlinear with excitation intensity.