Preparation of nanostructured TiO_2 thin films by aerosol flame deposition process

摘要

Titania thin films were prepared by using aerosol flame deposition process via the pyrolysis of titanium tetra-isopropoxide (TTIP) precursor. We analyzed the specific surface area, primary and secondary particle sizes, crystal structure, thin film morphology and thickness by BET method, electrophoretic light scattering, X-ray diffraction and scanning electron microscopy, respectively. The specific surface area of TiO_2 particles deposited is over three-times larger than that of commercial Degussa P25. Crystallite structure of TiO_2 particles can be controlled by changing the ratio of CH_4/O_2 flow rates. We could prepare TiO_2 thin films with single anatase phase by keeping the ratio of CH/ O_2 flow rates at 200 ml/min: 1,000 ml/min. As N_2 carrier gas flow rate to bubbler increases, the primary and secondary particle sizes increase, but decrease with increasing total N_2 gas flow rate through the central tube. The shorter the deposition height is, the smaller the deposition area is, but the thin film becomes thicker in the central region.