Dissertation > Excellent graduate degree dissertation topics show

Studies on the Photocatalysis of Transitional Metal Modified Titanium Dioxide

Author: MaShiLiang
Tutor: LiZhouPeng
School: Zhejiang University
Course: Chemical Engineering
Keywords: Titanium dioxide Copper Iron Hydrogen Methylene blue Photocatalysis Doping
CLC: TQ134.11
Type: Master's thesis
Year: 2013
Downloads: 1
Quote: 0
Read: Download Dissertation


Photocatalytic hydrogen generation and organic pollutants degradation have attracted more and more attention due to their environmental friendliness and sustainability. Among various photocatalysts, Titanium Dioxide (TiO2) is widely studied because of its stability, non-toxicity and low price. Photocatalytic activity enhancement of TiO2is a critical and hot issue in the recent research and development of TiO2photocatalyst. This work focuses on the synthesis and photocatalysis of transition metals modified TiO2photocatalysts. The functions of transition metals (Fe and Cu) in photocatalytic processes have been inveratigated in details.Using tetra-butyl orthotitanate as the catalyst precursor, nano TiO2was synthesized by typical sol-gel method. TiO2samples were characterized by differential scanning calorimetry (DSC), thermo gravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM) and optical diffuse-reflection spectrum (DRS), to understand the changes in structure and morphology in heat treatment process, and optimize the calcination temperature of TiO2. The synthesized TiO2in form of anatase with particle size between10and20nrn exhibits excellent photocatalytic activity, identified by methylene blue (MB) degradation and hydrogen generation, better than commercial TiO2.Bulk and surface Fe3+doped TiO2were synthesized by co-gel method and calcination, respectively. Their photocatalytic activities were evaluated by MB degradation and hydrogen production, respectively. It is found that bulk doping is detrimental to both processes (MB degradation and hydrogen production) but surface doping demonstrates a photocatalytic activity enhancement in MB degradation, revealing that doping position in TiO2plays a very important role in photocatalystic process. Doped Quantum-sized TiO2was synthesized by sol rotatory evaporation method to ensure that TiO2was treated by surface doping. The effect of surface doping disappeared after heat treatment of doped Quantum-sized TiO2, to have an effect of bulk doping. The difference in photocatalytic activity confirms that the surface doping and bulk doping demonstrates different effect in photocatalytic process. Fe3+decomposes MB while irradiated by UV. The adsorbed Fe3+species on surfaces of TiO2enhance MB degradation due to the photocatalytic synergy between Fe^and TiO2. A possible mechanism is suggested.Compared with Fe3+adsorption, Cu2+adsorption has different effects on photocatalytic activity. With increasing of Cu2+doping amount, photocatalytic reaction rates of both processes (MB degradation and hydrogen generation) increase firstly and then decrease. By characterizing the used catalysts through XRD, SEM and X-ray photoelectron spectroscopy (XPS) analysis, it is found that Cu2+is reduced into metallic Cu during hydrogen generation, behaving like Pt loaded TiO2·However, the Cu redox couple functions as a catalytic center in MB degradation process, which enhances the MB degradation. Excess Cu may form recombination centers, inhibiting the MB degradation process. Fe3+and Cu2+doping behave differently regarding to different redox reaction mechanisms, resulting different photocatalytic reaction processes to produce different adsorption effects on photocatalytic activity. A mechanism discussion has been made in this thesis.

Related Dissertations

  1. Preparation and Photocatalytic Properties for Water Decomposition of Titanate Photocatalyst,O643.36
  2. Preparation of ITO Quai-1D Nanostructures by Sol-Gel Method Combined with Porous Anodic Aluminum Oxide Template,TB383.1
  3. The Research on Action Mechanism of Additive Used in Through-Hole Copper Plating and Its Selection,TQ153.14
  4. ( Hydroxy) Iron Oxide and the removal of arsenic in drinking water,O614.811
  5. Study and Preparation of BaTiO3-based NTC Ceramic Thermistors,TQ174.1
  6. Process and Mechanism of Eucalyptus Pulp Bleaching Catalysed by Cu2+/Co2+,TS745
  7. Copper slag roasting modified experimental study,X758
  8. The Study on Metallogenic Regularities and Metallogenic Prediction of Nanpo Copper Deposit in Mengla County, Yunnan,P618.41
  9. First- principles calculations of doped anatase titanium dioxide photocatalytic properties,O643.36
  10. Study on the System of Continous Process for Hydrogen Production by Photosynthetic Bacteria,TQ116.2
  11. Study on the Exergy Analysis of Photosynthetic Biological Continuous Hydrogen Production System,TQ116.2
  12. New Technology and Basic Study on the Direet Preparation of PbO Powder from Galena by Selective Leaching Technology,TQ134.33
  13. Characterization and mechanism of the titanium dioxide surface envelope,TQ621.12
  14. The Application of Eggshell Membrane for Solid-phase Extraction and the Determination of Trace Metal Elements in Environment Water,X832
  15. Effects of Different Applying Methods of Copper and Zinc and AM Fungi under Different P-Applied Levels on Growth and Tanshinones of Salviae Miltiorrhizae Bunge,S567.53
  16. Effect of Iron, Manganese and Other Microelements on Growth and Effective Ingredients of Salviae Miltiorrhizae Bunge,S567.53
  17. The protective effect of the new gaseous signal molecule of non-steroidal anti-inflammatory drug -induced gastric lesions,R96
  18. Isolationand Identification of Mixed Photosynthetic Microbial and Their Hydrogen Production,TQ116.2
  19. Effects of Copper, Zinc and Selenium on Yield and Quality of Chrysanthemum Morifolium Ramat,S567.239
  20. The Modulatory Role and Relationship between Heme Oxygenase and Reduced Glutathione in High-Iron-Induced Oxidative Stress in Detached Leaves of Oryza Sativa L.,S511
  21. Kinase Activities Analysis and Localization of ZmCCaMK Induced by Abscisic Acid in Leaves of Maize Plants,S513

CLC: > Industrial Technology > Chemical Industry > Inorganic compounds, the chemical industry of the metal elements > Section IV metals elements inorganic compounds > Inorganic compounds of the element titanium vice family ( IV B family) > Inorganic compounds of titanium
© 2012 www.DissertationTopic.Net  Mobile