Study of photocatalytic activity and magnetic properties of Co, Mn metal ions doped nanocrystalline TiO2 prepared by Sol-Gel method

We report the growth of [Mn, Co]xTiO2 (x=0.01, 0.02 and 0.04) nanocrystals prepared by Sol-Gel technique, followed by freeze-drying treatment at −30 °C temperature for 12 h. The obtained Gel was thermally treated at different temperatures like 200, 400, 600 and 800 °C. The average crystalline size of 6-60 nm is achieved. The diffraction peak at 25.22°, 25.49° and 25.6° shows that the main crystal phase is anatase without any indication of other phases. Transition metal doping leads to the reduction in the oxygen vacancies on the TiO2 surface and suppresses the crystallization of other phases by adsorbing onto the surface of the TiO2 particles. The peak at 27.47° indicates the presence of the rutile phase at 800 °C. Valence metal cation, Mn, Co ions can react with Ti4+ on the surface of TiO2, and Ti4+ is reduced to Ti3+ which inhibits the transformation of anatase to rutile. The photocatalytic degradation of formaldehyde has been successfully demonstrated using a 250 W UV. The binary doped transition metal ions in TiO2 nanoparticles can lead the efforts of enhancing their environmental application as photocatalyst. Magnetic measurement was carried using VSM. The magnetic susceptibility of the Mn, Co doped TiO2 nanopowder increases with increase in doping concentration and exhibits room temperature ferromagnetism.