Preparation And Characterization Of Ion-doped Type And Oxide Or Noble-metal Supported Type Tio₂ Nano-wire(belt)

TiO₂ as a highly efficient environment functional material in the photocatalytic degradation of pollutants, photovoltaic conversion and new clean energy development has great application potential. But the traditional forms of TiO₂ in photocatalytic technology still have a lot of shortcomings on their practicality and application fields. In this paper, a new and efficient way to prepare a new TiO₂ nano-belts, and its modified products such as rare earth metal ions doped, perovskite-type titanate-barium strontium (barium) supported, non-metallic nitrogen-doped, novel metal silver supported TiO₂ nanobelts were made to look forward to the fundamentally improve in its photoelectric conversion efficiency and photocatalytic properties and broaden the value of practicality. A Systematic and in-depth study of the variety of modified nano-TiO₂ composite system with optimization of synthetic methods, product performance and characterization, photocatalytic activity evaluation was made.1. Different concentrations of NaOH solution, reaction time and temperature hydrothermal conditions was react with TiO₂ nanobelts, and the structure and morphology of further generated product was discussed. A variety of test results show that heat treatment in strong alkaline conditions of hydrothermal process is easy to produce nanobelts have a layered structure of the titanate, and the concentration of NaOH solution, hydrothermal reaction time and temperature on the morphology of the product and the mechanism is studied.2. A variety of testing methods to the two kinds layered structure titanate transformed into anatase TiO₂ nanobelts under hydrothermal process was made. the transformation difficulty and phase transformation mechanism was also discussed. Under certain conditions, the titanium sodium nanobelts not completely transformed into anatase TiO₂, if the increase in reaction temperature and extended reaction time, although it can be obtained pure anatase TiO₂, but the nanobelt morphology are severely damaged, in order to determine the optimal conversion conditions and methods, the titanium sodium titanate nanobelts or the convertion to anatase phase transformation of TiO₂ nano-belt mechanism was also deeply discussed.3. Er³⁺and/orYb³⁺ doped TiO₂ nanobelts was produced using layered structure of rare earth titanate nanobelts in Er³⁺,Yb³⁺solution under ion-exchange hydrothermal process. Various kinds Characterization method demonstrate that rare-earth ions has doped into the TiO₂ lattice, and show a strong up-conversion luminescence properties, by comparing the evaluation of its visible light photocatalytic degradation of Rhodamine B, the enhanced activity and its influencing factors and mechanism was studied.4. Cubic MTiO₃(M=Ba or Sr) nano-particles supported TiO₂ nano-composite materials was synthesize using Sr(OH)₂ or Ba(OH)₂ and TiO₂ nanobelts as the precursor under direct hydrothermal process. Product composition, phase, morphology, structure and optical properties were characterized in detail. The visible light photocatalytic degradation of Rhodamine B confirmed that all these nanocomposites have strong photocatalytic activity and highly surpass the commercial P-25 nano-particles.5. A simple process of the preparation with a high visible light photocatalytic activity degradation of Rhodamine B N-doped TiO₂ nano B-meta-stable was invented. Preparation process includes a NH4+ ion exchange at the room temperature and air calcination process. Different methods of characterization demonstrate that, N atoms doped into the TiO₂ (B) lattice caused a larger visible light absorption extension, also shown a higher photocatalytic activity than the undoped anatase TiO₂ nanobelts and commercial P-25 photocatalyst nano-particles in Degradation of organic dye.6. Ag support anatase TiO₂ nanobelts was synthesis at room temperature under the process of the Silver ammonia complex chemical reduction. A variety of analytical techniques was using to demonstrate the optical properties, the structure and morphology and final confirmed the 10-20nm Ag nano-particles support. After Ag supported, the visible light response capabilities was significantly broaden and composite system take the advantages of a substantial increase in separation efficiency of the carrier to create more efficient redox reactions also strengthen its visible light photocatalytic activity through the in-depth discusse and mechanism analysis.