Dissertation > Excellent graduate degree dissertation topics show

Preparation and Visible Light Catalytic Properties of C、N、F-doped TiO2 Nanoparticles

Author: WangCiCi
Tutor: ZhangYanFeng
School: Hebei Normal
Course: Physical and chemical
Keywords: TiO2 preparation C、N、F-doping visible light photocatalytic activity X-ray absorption fine structure
CLC: O643.36
Type: Master's thesis
Year: 2010
Downloads: 91
Quote: 0
Read: Download Dissertation

Abstract


Due to excellent photocatalytic properties, titanium dioxide has been widely used in many fields, such as degradation of pollutants, self-cleanning coating, and so on. However, more practical applications have been limited by its wide band gap, which require ultraviolet light as the optical excitation source. Shifting the optical response region of TiO2 to visible spectral range means that the sun light can be used as the optical excitation source. It is helpful for saving energy and environmental protection. So many researchers are focused on enlarging the optical response region of TiO2 to degrade organics under the sun radiation.It is an important way to prepare TiO2 with visible light response by doping nonmental. In this paper, a series of TiO2 photocatalysts were prepared using titanium tetrachloride as raw material. C-TiO2 was synthesized using citric acid as carbon source by a simple hydrolysis method. N-TiO2 and F-TiO2 with visible light response were prepared using NH4NO3 and NaF as doped sources by hydrothermal method. The structure, morphology and light adsorption of such photocatalysts were characterized by XRD, TEM, SEM, UV-Vis, XPS, X-ray absorption fine structure（XAFS）, etc. The photocatalytic degradation of methyl-orange was used as model reaction to evaluate the visible light activity of TiO2 samples. It suggested that a best doping concentration existed for every dopant and the mechanism of doped TiO2 for the visible-light activity was discussed.The research results were suggested as following:（1）The content of anatase phase of the sample rised with increasing amount of citric acid. The photocatalysts were well dispersed and their particle sizes increase with increasing amount of citric acid. The experimental result showed that the surface area of pure TiO2 was 92.232m2·g-1. After adding citric acid, the surface area of sample increased to 187.747m2·g-1. The increase of surface area was helpful to improve their photocatalytic properties.（2）With the addition of NH4NO3, the samples were rutile phase composed of nanorods. The surface area of undoped TiO2 was 41.479m2·g-1. When the addition amount of NH4NO3 was 0.4%, its surface area was 50.645 m2·g-1.（3）The TiO2 samples prepared with small amount of NaF were rutile phase with the morphology of the microspheres composed of nanorods. When the mole percentage of NaF to titanium ions was 2.0%, the anatase phase could be observed in the TiO2 powder. The content of anatase phase was 20.7% and the rutile phase was 79.3%, with the surface area of 40.355 m2·g-1.（4）The UV–Vis adsorption spectroscopy showed that C、N、F-doped TiO2 appeared a certain visible light adsorption and the optical band edge exhibited a certain red-shift compared with that of undoped TiO2 and Degussa P25. The photocatalytic activity of prepared samples were tested under 12W LED light with a major emission wavelength at 460nm as visible light source and methyl-orange as model reaction. The research suggested that the final degradation rate of the optimum samples were as following: 2.0%C-TiO2 was found to be nearly 90% within 3h. 0.5%N-TiO2, 0.4%F-TiO2 were about 62% and 72% within 5h.（5）The XAFS technique was employed to analyse the change of the local structure around Ti atom. It showed the structure information of doping atoms, such as coordination number, bond distance, etc. With the increasing of N and F dopant, the coordination number and Ti-O bond become bigger. XPS and XAFS analysis indicated that C and F atoms had been doped in the lattice of crystalline TiO2 by substituting the oxygen or Ti atom. Non-metal doping changed the energy band of TiO2 and improved photocatalytic activity under visible light irradiation.

Related Dissertations

  1. Studies on the Synthesis and Technology of Dipentaerythritol and Its Derivative,TQ223.164
  2. Preparation of Based on the Phenolic Resin of Activated Carbon and Adsorption-Photopcatalytical Character of Supported TiO2,TQ424.19
  3. Phosphorus pentoxide composite ammoniated condensing agent preparation of ammonium polyphosphate,TQ314.248
  4. The Preparation and Research of Magnetically Separable TiO2 Photocatalyst Nanofibers,TB383.1
  5. Preparation and Properties of Highly Active Dietary Fiber and Carboxymethylcellulose from Gracilaria Residue,TS254.9
  6. The Study of Preparation and Photocatalytic Activity of TiO2 by Electrospinning,O614.411
  7. Study and Preparation of BaTiO3-based NTC Ceramic Thermistors,TQ174.1
  8. First- principles calculations of doped anatase titanium dioxide photocatalytic properties,O643.36
  9. Of Bi N Co-doped TiO \u003csub\u003e 2 \u003c/ sub\u003e of the preparation and performance,O614.411
  10. Improvement of Preparation Technology for Chitin and Chitosan from By-product of Litopenaeus Vannamei,TS254.9
  11. Investigation of Fabrication, Characterization and Property of Fuctional Titanium Dioxide Nanoporous Materials,TB383.1
  12. Preparation and Performance of V2O5-WO3/MOx/Cordierite Catalyst Modified with Cu、Mn、Ce for DeNOx,X701
  13. Study on Properties of Ce、Co、Ni/V-W/TiO2 Modified by Composite Sol for Selective Catalytic Reduction,X701
  14. The Research of the Sludge Characteristics in the Cephalosporin Intermediate Pharmaceutical Wastewater by the Treatment of the NMBR,X787
  15. Synthesis and Quality Control Research of ATPR,TQ463
  16. Preparation of One-dimensional Nano TiO2 and Study on the Decolorization of Dyeing Wastewater,TB383.1
  17. Preparation and Evaluation on the Toxicological Safety and Stability of Deer Blood Wine,TS262.91
  18. The Research of Supramolecular Complexes of Edaravone and Cyclodextrins,R943
  19. The Comparative Study of the Reading Part of the Two Editions from Beijing University Press and People Education Press for Junior Chinese,G633.3
  20. Study on the Preparation Technology and Quality Standard of Danggui Dropping Pills,TQ461
  21. Photodegradation of Orange Ⅱ by Mesoporous TiO2,X791

CLC: > Mathematical sciences and chemical > Chemistry > Physical Chemistry ( theoretical chemistry ),chemical physics > Chemical kinetics,catalysis > Catalytic > Catalyst
© 2012 www.DissertationTopic.Net  Mobile