The Growth Mechanism and Morphology Control of Cathodically Deposited TiO2

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研究生：	許睆晴 Hsu, Huan-Ching
論文名稱：	The Growth Mechanism and Morphology Control of Cathodically Deposited TiO2 陰極沉積二氧化鈦的成長機制與形貌控制
指導教授：	胡啟章 Hu, Chi-Chang
口試委員:	汪上曉衛子健李玉郎胡啟章
學位類別：	碩士 Master
系所名稱：	工學院 - 化學工程學系 Department of Chemical Engineering
論文出版年：	2011
畢業學年度：	99
語文別：	英文
論文頁數：	115
中文關鍵詞：	二氧化鈦、陰極沉積
外文關鍵詞：	TiO2
相關次數：	點閱：2 下載：0
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This study presents a solution containing titanium trichloride and excess sodium nitrate used as a novel solution to deposit titanium dioxide films. The mechanism of cathodic deposition of titanium dioxide is examined by means of linear sweep voltammetry (LSV), ultraviolet-visible spectroscopy (UV-VIS), and in-situ ultraviolet-visible spectroscopy (in-situ UV-VIS). Based on the understanding about the growth mechanism of cathodically deposited titanium dioxide, hydrogen peroxide solution is used to modify the deposition bath and to enhance the deposited rate of titanium dioxide. The examinations of electrochemical quartz crystal microbalance (EQCM) and cyclic voltammetry (CV) prove the deposition rate in modified deposition bath is faster than that in before deposition bath, and the morphology and crystallinity are analyzed by scanning electron microscope (SEM) and x-ray diffraction (XRD).
The forementioned novel plating bath is applied in a dual-electrode system to prepare titanium dioxide films. In this work, the morphology of titanium dioxide can be controlled by bath temperature and deposition mode. The electrochemical characteristics of dual-electrode system and temperature effect are examined by LSV, and the microstructure of titanium dioxide is analyzed by SEM.
Moreover, this work demonstrates that various pulse times, relaxation times and frequencies can be adjusted to control the morphologies of titanium dioxide films. Morphology and particle size of titanium dioxide films, examined by means of SEM, is effectively controlled by change the pulse parameters. The analysis of XRD confirmed that well-crystalline titanium dioxide in pure anatase phase is prepared after the heat treatment.

Chapter 1 Introduction and Literature Review
1 Fundamentals of Electrochemistry .................................................................. 1
1.1 Electrochemical System and Reference Electrodes .............................. 1
1.2 Faradaic and Nonfaradaic Processes ..................................................... 6
1.3 Electrochemical Cells and Reaction Rate ............................................. 6
1.4 Factors Affecting Electrode Reaction Rate and Current ....................... 9
1.5 Introduction to Mass-Transfer-Controlled Reactions ......................... 10
1.6 Basic Electrochemical Thermodynamics ............................................ 13
1.7 Kinetics of Electrode Reactions .......................................................... 14
1.8 Introduction to Some Electrochemical Techniques ............................ 19
1.8.1 Linear Sweep Voltammetry (LSV) .......................................... 19
1.8.2 Cyclic Voltammetry (CV) ........................................................ 22
1.8.3 Controlled-Current Techniques ................................................ 25
1.8.4 Controlled-Potential Techniques .............................................. 27
2 Brief Review of TiO2 ..................................................................................... 30
2.1 Introduction of TiO2 ............................................................................ 30
2.2 Crystalline Phases of TiO2 .................................................................. 33
2.3 Photo-Electrochemical Applications of TiO2 ...................................... 37
2.4 Techniques for Fabrication of TiO2 Thin Films .................................. 42
2.4.1 Sol-Gel Method ........................................................................ 42
2.4.2 Chemical Vapor Deposition (CVD) ......................................... 43
2.4.3 Physical Vapor Deposition (PVD) ........................................... 43
2.4.4 Hydrothermal Method .............................................................. 44
2.4.5 Direct Oxidation Method ......................................................... 44
II
2.4.6 Microwave Method .................................................................. 45
3 Review on Electrodeposited TiO2 Films ........................................................ 45
3.1 Anodic Deposition .............................................................................. 46
3.2 Cathodic .............................................................................................. 51
3.3 Potentiodynamic Deposition ............................................................... 59
4 Motive and Purpose ....................................................................................... 61
Chapter 2 Experimental Methods
1 Chemicals and Instruments ............................................................................ 63
1.1 Chemicals ............................................................................................ 63
1.2 Instruments .......................................................................................... 63
2 Pre-preparation of Electrodeposition ............................................................. 64
2.1 Titanium Foil Electrode ...................................................................... 64
2.2 Electrodeposition Bath ........................................................................ 64
3 Electrodeposition Process .............................................................................. 65
3.1 Electrodeposition System.................................................................... 65
3.1.1 Three-electrode System ........................................................... 65
3.1.2 Dual-electrode System ............................................................. 66
3.2 Galvanostatic Electrodeposition ......................................................... 66
3.3 Potentiostatic Electrodeposition.......................................................... 67
3.4 Pulse Electrodeposition ....................................................................... 67
4 Electrochemical Analyses and Textural Characterizations ............................ 67
4.1 Electrochemical Analyses ................................................................... 67
4.2 Textural Characterizations .................................................................. 68
4.2.1 Scanning Electron Microscope (SEM) .................................... 68
4.2.2 X-ray Diffraction (XRD) ......................................................... 69
III
4.3 Optical Analyses ................................................................................. 70
4.3.1 Ultraviolet-visible Spectroscopy (UV-VIS) ............................. 70
4.3.2 In-situ Ultraviolet-visible Spectroscopy (in-situ UV-VIS) ...... 71
Chapter 3 The Growth Mechanism of Cathodically Deposited TiO2
1 Introduction and Motive ................................................................................ 72
2 Results and Discussion .................................................................................. 74
2.1 In-situ UV–VIS and UV–VIS absorption spectroscopic analysis ...... 74
2.2 LSV investigation ............................................................................... 76
2.3 Effect of hydrogen peroxide ............................................................... 81
3 Conclusion ..................................................................................................... 85
Chapter 4 Preparation of TiO2 Films via Dual-Electrode Electrochemical System
1 Introduction and Motive ................................................................................ 87
2 Results and Discussion .................................................................................. 88
2.1 Electrochemical Characteristic of Dual-Electrode System ................. 88
2.2 Effects of Deposition Temperature ..................................................... 90
2.3 Effects of deposition mode ................................................................. 94
3 Conclusion ..................................................................................................... 95
Chapter 5 Nanostructural Evolution in Pulse Plated TiO2 Electrodeposits
1 Introduction and Motive ................................................................................ 97
2 Results and Discussion .................................................................................. 98
2.1 Effects of pulse time and relaxation time............................................ 98
2.2 Effect of pulse frequency .................................................................. 102
3 Conclusion ................................................................................................... 103
IV
Chapter 6 Conclusion and Future work ..................................................... 105
References .............................................................................................................. 107

                                

1. Bard, A.J. and L.R. Faulkner, eds. Electrochemical Methods: Fundamentals and Applications, 2nd Edition. 2001, John Wiley & Sons Inc: New York.
2. El Goresy, A., et al., A natural shock-induced dense polymorph of rutile with alpha-PbO2 structure in the suevite from the Ries crater in Germany. Earth and Planetary Science Letters, 2001. 192(4): p. 485-495.
3. El Goresy, A., et al., An ultradense polymorph of rutile with seven-coordinated titanium from the Ries crater. Science, 2001. 293(5534): p. 1467-1470.
4. Earnshaw, A. and N. Greenwood, eds. Chemistry of the Elements, Second Edition. 1997, Butterworth-Heinemann.
5. Oregan, B. and M. Gratzel, A LOW-COST, HIGH-EFFICIENCY SOLAR-CELL BASED ON DYE-SENSITIZED COLLOIDAL TIO2 FILMS. Nature, 1991. 353(6346): p. 737-740.
6. Fujishima, A., Discovery and applications of photocatalysis-Creating a comfortable future by making use of light energy-, in Japan Nanonet Bulletin. 2005.
7. Dubrovinsky, L.S., et al., Materials science - The hardest known oxide. Nature, 2001. 410(6829): p. 653-654.
8. Chiang, Y.M., D.P. Birnie, and W.D. Kingery, eds. Physical Ceramics. 1997, Wiley: New York.
9. Konenkamp, R., ed. Photoelectric Properties and Applications of Low-Mobility Semiconductors. 2000: Berlin.
10. Subramanian, V., E.E. Wolf, and P.V. Kamat, Catalysis with TiO2/gold nanocomposites. Effect of metal particle size on the Fermi level equilibration. Journal of the American Chemical Society, 2004. 126(15): p. 4943-4950.

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