Fabrication, Modification and Application of Visible Light Responsive TiO2 Nanotubes

The highly ordered TiO2 nanotube arrays have demonstrated remarkable properties that include solar cells, hydrogen sensors, drug eluting surfaces, hydrogen generation, and water purification along with numerous other applications. Built upon a suitable fabrication approach that enable significant differences in reproducibility as well as the large scale production with low cost plus investigation of the effective way to increase its visible light response so that create environmental friendly alternative energy sources were the motivations of this work, Since the field has grown so rapidly as to make it difficult to summarize the scope of all related work, some key aspects on this field have been discussed and then mainly focus on the work that has been done during my Ph.D study. This Ph.D work focuses on the most challenging issues: 1) improves the tune quality of highly ordered TiO2 nanotubes by reproducible manner as well as reduces the cost of fabrication. 2) Investigates the different methods of modification in order to increase photo response of the materials in visible light region. 3) Explore the surface superhydrophobic property of fluorinated TiO2 nanotubes layer. Following progresses have been made towards the target. An innovative technique of sonication assisted fabrication of highly ordered TiO2 nanotubes in reproducible manner was proposed and the expensive platinum cathode was replaced by titanium by which the fabrication cost was reduced. A one-step method for the fabrication of Fe–C–N-codoped TiO2 nanotubes by electrochemical anodization is reported. A maximum photocurrent efficiency of 2.7% was achieved. Highly ordered nitrogen-doped titanium dioxide (N-doped TiO2) nanotube array films with enhanced photo conversion efficiency were reported and the conditions were optimized. The optimized experiment resulted in 7.42% PCE which was within 95% confidence interval of the predicted value by the model. The structural and photo catalytic properties of Pt/ZIF-8 loaded TiO2 nanotubes (TiO2 NTs) are investigated and compared to Pt/TiO2 NTs. The Pt/ZIF-8 loaded TiO2 NTs has shown 18.6% oxidation towards phenol in 2 hours under visible light. Finally, a simple process of tailoring the surface wettability of TiO2 nanotube array surface was proposed by which any desirable degree of hydrophobicity between 100o to 170o can be achieved