Assessment of atomic layer deposited TiO2 photocatalytic self-cleaning by quartz crystal microbalance

The self-cleaning properties emerging from photocatalytic effects consist in the elimination of an organic contamination layer by light-induced redox reactions. Quartz crystal microbalances (QCMs), monitoring the contaminant mass loss under UV illumination, were used to investigate this effect and its efficiency. A new setup dedicated to such purpose is introduced along with the results of a self-cleaning experiment performed with a 20-nm TiO2 thin film coated on a QCM by atomic layer deposition. In particular, a 10-nm paraffin oil thin film deposited under vacuum is shown to be degraded down to its complete removal according to a zeroth order photocatalytic reaction. Finally, the experimental opportunities offered by the new setup, such as a controlled environment composition, are presented.