Synthesis and characterisation of TiO 2 nanostructures for photocatalytic applications

Titanium dioxide (TiO2) nanoparticles and thin films were successfully prepared by sol-gel method using Titanium tetraisopropoxide (Ti(OCH(CH3)2)4) as precursor and tetramethylammonium hydroxide (TMAOH) as structuring agent, while varying TIPT:TMAOH ratio (2:1 and 2:2). X-ray diffraction analysis confirms the formation of nanocrystalline anatase phase after crystallisation starting from 300°C, and that the crystallite size increases with temperature due to grain growth. Both Raman spectroscopy and X-ray diffraction analyses confirm the formation of anatase phase. The optimised results were achieved by using the molar ratio C = Ti/TMAOH = 2/2, namely a perfectly crystallised and monodispersed material from the temperature 400°C and allows the obtaining thin films transparent to visible light and ultraviolet irradiation. A photocatalytic activity of TiO2 films was implemented by photodegradation of methylene blue under ultraviolet irradiation. The thin films calcined at the temperature of 400°C display the highest photocatalytic activity.