Influence of Mg, Cu, and Ni Dopants on Amorphous TiO₂ Thin Films Photocatalytic Activity

The present study investigates Mg (0 ÷ 17.5 wt %), Cu (0 ÷ 21 wt %) and Ni (0 ÷ 20.2 wt %) dopants (M-doped) influence on photocatalytic activity of amorphous TiO₂ thin films. Magnetron sputtering was used for the deposition of M-doped TiO₂ thin films. According to SEM/EDS surface analysis, the magnetron sputtering technique allows making M-doped TiO₂ thin films with high uniformity and high dopant dispersion. Photocatalysis efficiency analysis was set in oxalic acid under UV irradiation. In accordance with the TOC (total organic carbon) measurements followed by the apparent rate constant (k) results, the dopants' concentration peak value was dopant-dependent; for Mg/TiO₂, it is 0.9% (k-0.01866 cm^-1), for Cu/TiO₂, it is 0.6% (k-0.02221 cm^-1), and for Ni/TiO₂, it is 0.5% (k-0.01317 cm^-1). The obtained results clearly state that a concentration of dopants in TiO₂ between 0.1% and 0.9% results in optimal photocatalytic activity.