Formation of Metal-Organic Decomposition Derived Nanocrystalline Structure Titanium Dioxide by Heat Sintering and Photosintering Methods for Advanced Coating Process, and Its Volatile Organic Compounds’ Gas-Sensing Properties
Tohru Sugahara, Leila Alipour, Yukiko Hirose, Yusufu Ekubaru, Jun‐ichi Nakamura, Hironobu Ono, Nobuyuki Harada, Katsuaki Suganuma
Abstract
The metal-organic decomposition (MOD) method, which is a nanoscale film-forming process, has attracted much attention as the next generation of advanced coating techniques. Functional thin films of metals and metal oxides, especially nanostructural materials, are required to be formed on any substrate through reduced raw materials/resources, while also saving energy and using low-cost materials in the fabrication process. In this study, titanium dioxide (TiO2) nanocrystalline structure thin films have been directly synthesized successfully while also demonstrating growth on the substrate using the MOD method, a process combining the coating and heat sintering or photosintering. We obtained two kinds of dendrimerlike and spherelike nanostructural morphologies as TiO2 at low temperatures in both the heating and photosintering techniques through the capping and redaction effects of stabilizers in our two precursors. In particular, metal oxides film formed successfully on plastic substrate without any damage to the substrate. The gas sensor device from the spherelike TiO2 nanostructure by the MOD method shows an excellent high-speed gas-sensing response and recovery time because the TiO2 nanocrystal structures have a large surface area and a highly crystalline structure, which are useful for applications in both universal electronic devices and gas sensors.