The Preparation And Functionalization Of TiO₂ Nanotube Arrays And The Study Of Their Application In Electrochromic Device And Protein Isolation

In recent years, TiO2 nanotube arrays have attracted great attention in pollution decomposition, solar cell, water splitting, electrochromic device, biomaterials electrochromic biomdecular detection and other fields due to their excellent photocatalyis ability, large surface area and stable chemical properties and good biocompatibilityIn this study, the TiO2 nanotube arrays were prepared electrochemical anodization, and treated by chemical doping, etching, annealing and other experimental procedures. The resultant composite nanotube arrays were applied in the constructing electrochromic device and extracting of protein molecules. The main contents are as follows:Chapter 1 gives a brief describe on the definition, characterization and preparation methods of TiO2 nanotubes, and also outlines the application of TiO2 nanotube arrays in electrochromic device and biomolecular extraction.Chapter 2 studies the preparation, characterization and application of TiO2/Ag3PO4 nanotube composites in electrochromic. Ag3PO4 was prepared by sequential chemical bath deposition. The samples were characterized by SEM, EDS, XRD and FT-IR. And the mechanism of electrochromic reaction was studied by electrochemical technique. In the current work, the TiO2/Ag3PO4 nanotubes prepared by 15 decorating cycles and the treated without annealing shows the best electrochromic performance.Chapter 3 studies the extraction of Hemoglobine (Hb) on TiO2 nanotubes. In this study, After the TiO2 nanotube layer was synthesized by electrochemical anodization, it was detached from the foil by diping the sample in H2O2. By etching the nanotube bottom with HF gas for some time, the bottom of nanotubes become open. The resulting samples were then annealed at 450 ℃ for 2 hours in N2 atmosphere to form carbon decorated TiO2 (C/TiO2) nanotubes. The samples were applied in the protein isolation. When the pH value of phosphate buffer solution (PBS) is 6.4, an adsorption efficiency of 85% was achieved for 1mL 180 mg/L Hb by using 3.0 mg of C/TiO2 nanotubes as sorbent. The isolated Hb molecules could be readily recovered by a Tris-HCl butter solution (pH 8.8), with a recovery efficiency of-75%. Circular dichroismanalysis demonstrated the recovered protein still kept good activity. In summary, the prepared C/TiO2 nanotubes have good biocompatibility and the adsorption/desorption procedures didn’t influence the conformation and activity of Hb molecules.