Development of pure rutile TiO$_2$ and Magneli titanium sub-oxide microstructures over titanium oxide-seeded glass substrates using surfactant-free hydrothermal process

摘要

Titanium oxide seed layer was coated over glass substrates by sola??gel spin coating method. Single-step surfactant-free hydrothermal process developed titanium oxide microstructures over the titanium oxide-seeded glass substrates.Various morphologies of titanium oxide microstructures, varying from coral reefs to flower-like morphology were evolved by changing HCl concentration (1 and 3 M) in the precursor solution and growth temperature (GT) (120, 150 and180$^{circ}$C) of the hydrothermal process. Structural studies confirmed the formation of rutile TiO2, TiO$_2$ $+$ Ti$_2$O$_3$ and Ti$_4$O$_7$ microstructures due to varying the concentration of HCl (1 and 3 M) in the solution and GTs. Morphological studies revealed the possibility of engineering coral reefs, cauliflower, flowers, ball, cactus and jasmine flower-shaped microstructures oftitanium oxide films by tuning the growth parameters. The indirect band gap of the titanium oxide microstructures derived from UVa??Vis absorption spectra lies in the range of 2.9a??3.02 eV.