Multivariate optimisation of TiO2/carbon nanocomposites for photocatalytic degradation of a reactive textile dye

In this study, the effect of synthesis variables on the photocatalytic activity of TiO2 nanoparticles and TiO2/C nanocomposites was evaluated by factorial design using a reactive dye as a model substrate. The most significant result demonstrated a significant effect of the pyrolysis temperature on the photocatalytic performance of both materials. For TiO2 nanoparticles, the lower temperatures of pyrolysis enhanced the photocatalytic activity because of the lower rutile content. Conversely, for nanocomposites, the optimum condition was represented by higher temperatures of pyrolysis, which resulted in greater concentrations of the rutile phase. In the latter case, the higher activity observed for the rutile phase was clear evidence of the favourable effect of the presence of carbon.