MICROSCALE MESHES OF Ti3O5 NANO- AND MICROFIBRES PREPARED VIA ANNEALING OF C-DOPED TiO2 THIN FILMS

A new technique to produce microscale Ti3O5 nano- and microfibre meshes is reported. When a 3 wt% carbon-doped TiO2 film on Si(100) was annealed at 1000 C in wet nitrogen (0.8% H2O), the amorphous TiO2 phase gave rise to crystalline phases of lambda-Ti3O5 (75%) and rutile + trace of TiO2-xCx (25%). From Raman and FTIR spectroscopy, it was concluded that rutile was formed at the inner layer located at the interface between the mesh and Si that was located away from the surface such that meshes of nano- and microfibres were predominantly composed of Ti3O5 grown from the reaction of rutile with Si to form Ti3O5 and SiO2. The microscale mesh of nano- and microfibres showed increased photoluminescence compared with amorphous TiO2. The PL spectrum which had a broad band in the visible spectrum, fitted three broad Gaussian distributions centred at 571.6 nm (about 2.2 eV), 623.0 nm (about 2.0 eV) and 661.9 nm (about 1.9 eV).