Microscale meshes of Ti3O5 nano- and microfibers prepared via annealing of C-doped TiO2 thin films

A new technique to produce microscale Ti3O5 nano- and microfiber meshes is proposed. When a 3 wt% carbon-doped TiO2 film on Si(1 0 0) was annealed at 1000 °C in wet nitrogen (0.8%H2O), the amorphous TiO2 phase gave rise to crystalline phases of λ-Ti3O5 (75%) and rutile + trace of TiO2−xCx (25%). From Raman and FTIR Spectroscopy results, it was concluded that rutile is formed at the inner layer located at the interface between the mesh and the Si that was located away from the surface such that the meshes of nano- and microfibers are predominantly composed of Ti3O5 grown from the reaction of rutile with Si to form Ti3O5 and SiO2. On the other hand, it was noteworthy that the microscale mesh of nano- and microfibers showed increased photoluminescence compared with amorphous TiO2. The PL spectrum which had a broad band in the visible spectrum, fitted as three broad Gaussian distributions centered at 571.6 nm (∼2.2 eV), 623.0 nm (∼2.0 eV) and 661.9 nm (∼1.9 eV).

► A new technique to achieve randomized microscale meshes composed of Ti3O5 nano- and microscale fibers is presented. ► The structure was obtained by thermal annealing of carbon-doped TiO2 thin films (with two different carbon concentration: 1.5 wt% and 3 wt%). ► The properties are investigated by different characterization techniques.