| Titre : | Effect of Cesium doping on the properties of Titanium dioxide thin films elaborated by Sol- gel (Spin coating) and their photocatalytic applications. |
| Auteurs : | DOUBA OUISSAL, Auteur ; Hanane Saidi, Directeur de thèse |
| Type de document : | Monographie imprimée |
| Editeur : | Biskra [Algérie] : Faculté des Sciences Exactes et des Sciences de la Nature et de la Vie, Université Mohamed Khider, 2023 |
| Format : | 1 vol. (94 p.) / ill., couv. ill. en coul / 30 cm |
| Langues: | Anglais |
| Mots-clés: | Thin films, TiO2, Cs, spin coating, doping, photocatalysis, methyl orange. |
| Résumé : |
In this study, we were prepared thin films by Sol-gel (spin coating) technique onto glass substrates with doping percent varied from 0 at% to 2 at%. The influence of Cs doping on structural, optical, electrical and photocatalytic properties were investigated, then they were characterized using X-ray diffraction, UV-Visible spectroscopy, Scanning Electron Microscopy (SEM) and four-point probe method for electrical measurement. The obtained results show that the films are a polycrystalline nature with prefertional orientation along to (101) plane corresponding to anatase phase. The crystallite size of the films increased with the increasing of Cesium doping concentration. The optical analyses depict that the films have a high transmission in the visible range about 80–92%. Also, thin layers of (TiO2: |
| Sommaire : |
General introduction...............................1 References.................... 2 Chapter 01: Generalities about Titanium dioxide I.1. Transparent conducting oxide (TCO)……………………………………………………...3 I.1.1. Definition……………………………………………………………………………...3 I.1.2. Applications of TCO films…………………………………………………………….3 I.2. Titanium Dioxide…………………………………………………………………….……..4 I.2.1. Definition ........................................4 I.2.2. Choice of Titanium dioxide.....................................4 I.2.3. Titanium Dioxide properties...............................5 I.2.3.1. Structural properties ....................................5 I.2.3.2. Optical properties ...........................7 I.2.3.3. Electronic properties..........................8 I.2.5. Applications of Titanium Dioxide .........................9 I.2.5.1. Application in electrochromic systems........................9 I.2.5.2. Applications photovoltaic ...............9 I.2.5.3. Gas sensors.....................................10 I.2.5.4. Photocatalytic applications ............11 I.2.6. Kinds of doped semiconductors...............14 I.2.6.1. Elements doped Titanium dioxide........15 I.2.6.2. Choice of Cesium as a doping element..........16 Refer.................................... 17 Chapter 02: Sol-gel (spin-coating) and characterization methods II.1. General concept of thin films……………………………………………………………20 II.1.1. Definition .........................20 II.1.2. Difference between bulk state and thin film of the material.......20 II.1.3. Relation between thin layer and substrate ....................20 II.1.4. Thin film modes and growth mechanisms .........................20 II.1.5. Thin film deposition procedure ...................22 II.1.6. Application of thin films ........................................22 II.1.7. Thin films depositions techniques .................23 II.2. Sol gel technique ................23 II.2.1. Definition..................................23 II.2.2. Basic idea of the sol-gel process...............24 II.2.3. Precursors .............24 II.2.4. Reaction mechanisms................5 II.2.5. Parameters influencing reaction kinetics.........................27 II.2.6. Advantages of sol gel technique ....................27 II.2.7. Densification of thin layers................................27 II.2.8. Different sol gel processes...............................................28 II.3. Characterization methods..............................................31 II.3.1. X-ray’s diffraction (XRD) ..............................32 II.3.2. Spectroscopy (UV-VISIBLE).................................33 II.3.3. Four-point probe method............................................36 II.3.4. Scanning Electron Microscopy (SEM)....................37 References........................................... 38 Chapter 03: Experimental procedures, results and discussions III.1. Experimental details……………………………………………………………………..41 III.1.1. Preparation of the substrate………………………………………………………….41 III.1.1.1. Choice of substrate……………………………………………………………..41 III.1.1.2. Cleaning of the substrate......................42 III.1.2. Preparation of the solution............................................42 III.1.3. Depositing of thin films..............................43 III.2. Results and discussions ..............................................45 III.2.1. Adhesion test..................................45 III.2.2. Structural characteristics.............................................45 III.2.2.1. X-ray diffraction ..................................45 III.2.2.2. Crystallite size, micro-strain and dislocation density .48 III.2.2.3. Lattice parameters..50 III.2.3. Optical properties ...50 III.2.3.1. Transmittance and reflectance spectra .....................50 III.2.3.2. Optical gap and Urbach energy .............52 III.2.4. Thickness of the filM.Surfacemorphology.....55 III.2.6. Electrical properties.....56 III.2.7. Photocatalytic studies ..57 III.2.7.1. General characteristics of methyl orange dye....................57 III.2.7 2. Photocatalytic degradation of methyl orange solution by (TiO2: Cs) thin films 57 III.2.7.3. Photocatalytic reaction rate constant (Kapp)….... 60 General conclusion ..........62 References............... 64 Annexe.......... 66 |
Disponibilité (1)
| Cote | Support | Localisation | Statut |
|---|---|---|---|
| MPHY/614 | Mémoire master | bibliothèque sciences exactes | Consultable |
