Correlation between Photocatalysis and Antibacterial Responses of Cu-Doped TiO₂ Films: Influence of Doping Tuning into the Oxide Matrix

Herein, a study on the photocatalysis and antibacterial performances of Cu-doped titania films as a function of the dopant concentration is presented. The TiO2 films are produced by sol-gel spin-coating technique, and the doping is performed by adding different quantities of copper in the form of salt (CuSO4) during the preparation of sol. The obtained films are characterized by Raman and X-ray diffraction spectroscopies, atomic force microscopy, and Rutherford backscattering spectrometry, to investigate on the chemical-physical properties, the quality, the composition, and the thickness. The photocatalytic activity of the films is studied by measuring the degradation of methylene blue (MB) under UV light, while Staphylococcus aureus is chosen for microbiological testing. The results show a correlation between photocatalysis and antibactericity with a rise of these two activities with increasing dopant concentrations in the films up to a given point, beyond which structural defects are introduced, promoting electron-hole recombination.