On the connection between photo catalytic activities and magnetic properties of TiO2−x films

Pure and Mn-doped TiO2−x films were grown on corning glass substrates by the pulsed laser deposition (PLD) system in vacuum at two different temperatures, 350 °C and 580 °C. The films grown at 350 °C were non-crystalline while those grown at 580 °C were semi-crystalline. The effect of Mn on TiO2−x films for photocatalytic activities and paramagnetic properties were investigated. The results revealed that the films grown at 580 °C photos-degrade Rhodamine-6G (Rh-6G) and Methyl Orange (MO) faster than those of 350 °C with the 10% Mn films showing an enhanced performance. On the contrary, the 350 °C grown films photo-degrades Methylene Blue (MB) much faster than the 580 °C films with the 20% Mn doped film being the most efficient. In both temperatures, the 20% Mn films possess highest MB degradation rate and spin concentration at 150 and 310 mT fields. The 10% Mn film at 580 °C possesses the highest degradation rate of both Rh-6G and MO but has the lowest spin concentration at 150 mT field. In addition, it was also found that the non-crystalline formation further enhances the degradation of MB dye.