Controlled Structure and Growth Mechanism behind Hydrothermal Growth of TiO2 Nanorods
Aschariya Prathan, Jongrak Sanglao, Tao Wang, Chawalit Bhoomanee, Pipat Ruankham, Atcharawon Gardchareon, Duangmanee Wongratanaphisan
Abstract
Abstract Fabrication of uniform vertically-aligned titanium dioxide nanorods (TiO 2 NRs) was achieved by hydrothermal growth on a fluorine-doped tin oxide (FTO) glass substrate. The substrate was coated by a TiO 2 seed layer composed of titanium (IV) butoxide (TBO) as a precursor in an HCl solution. To reduce the amount of toxic substances used in this work, a minimal amount of HCl was used. On a larger scale, this method would require less precursor and therefore be a cost-savings. The aim of the present work is to achieve high crystalline orientations of TiO 2 NRs for low quantities of both TBO precursor and HCl solutions. Results showed that the 0.7% TBO TiO 2 NRs after 1.5 h of hydrothermal treatment exhibited the optimal crystalline orientation along [001] while the (002) plane is the dominant facet. The results demonstrate high transmittance of visible light and well-formed crystalline structures that offer a fast electron pathway along the length of the TiO 2 NRs with less grain boundaries. Lastly, TiO 2 NRs and their growth mechanism are discussed. This work offers a promising hydrothermal method for growing well-aligned TiO 2 single-crystal NRs that can be employed in solar cell applications.