Boosting the Optical Activity of Titanium Oxide Through Conversion from Nanoplates to Nanotubes and Nanoparticle-Supported Nanolayers

The nano-architecture of titanium oxide is a key element of a wide range of applications, mainly optical and catalytic activities. Therefore, the current study focuses on engineering and designing three interesting nanostructures of titanium oxides: nanoplates, nanotubes, and nanoparticle-supported nanolayers. The nanoplates of titanium oxides were prepared and confirmed by TEM images, X-ray diffraction, and EDX analysis. These nanoplates have an anatase phase, with the distance across the corners in the range of 15 nm. These nanoplates were modified and developed through a rolling process with sodium doping to generate the Na-doped TiO2 nanotubes. These nanotubes were observed by TEM images and X-ray diffraction. In addition, the doping process of titanium oxides with sodium was confirmed by EDX analysis. A novel nano-architecture of titanium oxide was designed by supporting titanium oxide nanoparticles over Zn/Al nanolayers. The optical properties and activity of titanium oxides with the different morphologies indicated that titanium oxides became a highly photo-active photocatalyst after conversion to nanotubes. This finding was observed through the reduction in the band gap energy to 2.7 eV. Additionally, after 37 min of exposure to UV light, the titanium oxide nanotubes totally broke down and transformed the green dye of NGB into carbon dioxide and water. Furthermore, the kinetic analysis verified that the green dyes’ degradation was expedited by the high activity of nanotubes. Ultimately, based on these findings, it was possible to design an efficient photocatalyst for water purification by converting nanoplates into nanotubes, doping titanium sites with sodium ions, and creating new active sites for titanium oxides through defect-induced super radical formation.