Fig. 7
Detailed carrier dynamics in TiO2/BiVO4 heterostructures, and the presence of localized polaronic mid-gap states can enhance the interfacial carrier transfer and recombination in TiO2/BiVO4 heterojunctions. PL kinetics of BiVO4 in BiVO4 and TiO2/BiVO4 under (a) 400 nm and (b) 500 nm excitation. The solid curves represent the fitting results using the parameters listed in Table S1. (c) TA spectra of TiO2, BiVO4 and TiO2/BiVO4 collected at 3 ps. The TA spectra of TiO2/BiVO4 contain contributions from both TiO2 and BiVO4. (d) TA spectra of TiO2/BiVO4 in ethanol at indicated delay times under 430 nm excitation, exhibiting a red shift with the increase of delay time. (e) Normalized TA kinetics of TiO2 and TiO2/BiVO4 in ethanol probed at 952 nm, reflecting the decay of electrons. (f) Corresponding kinetics of holes probed at 1100 nm. Solid lines show the results of exponential fitting by using the parameters listed in the figure and Table S2.
