Enhanced photocatalytic activity in low-temperature processed titania mesoporous films

The possibility of extending the technological applications of photocatalytic mesoporous titania films relies upon the capability of lowering the processing temperature while maintaining its functional properties. Here we present a synthesis of mesoporous titania films, which makes use of a partially fluorinated surfactant Zonyl FS300 as a mesostructuring agent. The photoinduced degradation activity has been followed by FTIR spectroscopy as a function of the films' thermal annealing, ranging from 150 up to 400 °C, by using stearic acid as a model compound. The results have been compared with the benchmark templating agent Pluronic F127 and highlighted a constantly higher activity of the Zonyl-templated films, up to 50%, throughout the range of the temperatures analyzed. Raman spectroscopy indicates that Zonyl FS300 is capable of producing nanosized titania crystals at temperatures lower than Pluronic F127. This explains the different photocatalytic response of the corresponding mesoporous thin films processed at low temperatures.