Dataset for "Probing P25 TiO2 Photocatalysis using Photoinduced Absorption Spectroscopy (PIAS)"

Dataset for "Probing P25 TiO2 Photocatalysis using Photoinduced Absorption Spectroscopy (PIAS)"

Abstract:
Photoinduced absorption spectroscopy, PIAS, is used for the first time to probe the kinetics exhibited by the most commonly employed powder photocatalyst, P25 TiO2, in mesoporous film form, in the photocatalysed oxidation of a commonly used test organic pollutant, 4-chlorophenol, 4CP. The results show that PIAS can provide previously unobtainable, invaluable, direct kinetic, and mechanistic, information concerning photogenerated holes in powdered photocatalysts.

Dataset contains 4 figures from research paper. These files are xlsx format. Details of the figures are included below:
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Fig. 1 LSV’s (5 mV s-1) recorded for a P25 TiO2 photoanode in the absence (black line) and presence (red line) of 0.1 M 4CP (in O2-free, 1 M HClO4), with (solid line) and without (broken line) UV irradiation (365 nm, 40 mW cm-2).

Fig. 2 Plots of the measured (a) photocurrent, J, and (b) change in absorbance at 500 nm, ΔAbs, as a function of time, exhibited by a P25 TiO2 photoanode poised at -0.19 V vs. Ag/AgCl and in 0.1 M 4CP (in O2-free, 1 M HClO4), before, during and after steady state irradiation, produced using different 365 nm UV irradiances. In both plots the UV irradiances used were (from bottom to top): 113, 56, 36, 33, 21 and 6 mW cm-2, respectively. In (b), lines of best fit to the light-off decays all give excellent fits to first order kinetics with a 1st order rate constant, k1 = 0.3 s-1.

Fig. 3 (a) Plots of the steady state photocurrents, Jss and the changes in absorbance, ΔAbsss, due to the photocatalysed oxidation of 4CP by a P25 TiO2 photoanode polarised at -0.19 V vs. Ag/AgCl (in O2-free, 1 M HClO4), as a function of UV irradiance, ρ. In both profiles the solid lines of best fit have been calculated assuming Jss and ΔAbsss are proportional to ρθ, where θ = 0.60; and (b) plot of Jss vs. ΔAbsss, revealing a good straight line with zero intercept.

Fig. 4 Plots of the measured change in absorbance at 500 nm, ΔAbs, as a function of time, exhibited by a P25 TiO2 photoanode in 0.1 M 4CP, O2-saturated, 1 M HClO4, solution, before during and after steady state irradiation, using different 365 nm UV irradiances. The UV irradiances used were (from bottom to top): 76, 36, 17, 9 and 2 mW cm-2, respectively. The lines of best fit to the light-off decays all give excellent fits to first order kinetics with a 1st order rate constant, k1 = 0.29 s-1.