Fig. 6

EIS Nyquist plots of a (SnNb₂O₆), b (the mixed phases of SnNb₂O₆ and Sn₂Nb₂O₇), and c (Sn₂Nb₂O₇) samples (a). Comparison of transient photocurrent response of the samples with light on/off cycles under white (neutral) light irradiation (LED 690 lm, [Na₂SO₄] = 0.2 M) (b). Transient absorption spectra measured at a delay time of 0.3 ms (c). Transient absorption decay kinetics of the prepared samples at an excitation wavelength of 600 nm (d)