As expected, in this reactivity test, the formation rates with the TiO2 photocatalyst produced by TTIP are also significantly higher than the photocatalyst produced with P25. Uncalcined, the formation rate constant of aniline with the photocatalyst derived from TTIP is 0.641 mM min -1 in comparison to 0.452 mM min -1 for the coating derived from P25 photocatalyst particles. Again, the formation rate constants of the plates coated with P25 decrease with subsequent coating and laser-treatment steps. The plates coated with TTIP again show an improvement in aniline formation, up to 1.39 mM min -1 after two coating and annealing steps, which corresponds to an improvement of 117 % over the non-laser treated sample. However, aniline formation decreases thereafter, likely as the coating becomes too thick for efficient charge carrier transport to the outer surface where the reaction takes place. The aniline formation is nevertheless still higher case compared to the plates coated with P25.