Figure 7

(a,b) Kinetic parameters as deduced from IMPS measurements with \(k_{\mathrm{rec}}\) being the surface hole recombination rate (a, filled symbols), \(k_{\mathrm{ct}}\) the surface hole charge transfer rate (a, open symbols), and \(\eta _{\mathrm{ct}}\) the hole charge transfer efficiency (b) at different potentials. (c) Log-log plot of electron lifetime \(\tau _{\mathrm{n}}\) versus incident photon flux \(\Phi _{\mathrm{photon}}\) as retrieved from IMVS measurements. Solid lines represent linear least-square regressions of each data set with the obtained slopes given in the legend. (d) Electron transit times \(\tau _{\mathrm{D}}\) for each \(\hbox {TiO}_2\)-coated FTO retrieved from IMPS measurements at different applied potentials and under 369 nm \(100\,\hbox {W}/\hbox {m}^2\) irradiation. The drawn lines in (a,b,d) serve as guide to the eyes.