Titre : | Effect of PH precursor on properties of TiO2 thin films deposited by ultrasonic spray process and their photocatalytic applications |
Auteurs : | HERIBI OUISSAL LATRA, Auteur ; Abdallah Attaf, 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 : | 1vol(86) |
Langues: | Français |
Mots-clés: | Titanium dioxide TiO2, thin films, PH precursor, structural, morphological, and optical properties, ultrasonic spray process, photocatalytic application, Methyl Orange, simulated solar light irradiation (UV-A). |
Résumé : |
In this memory, we study the effect of PH precursor on the structural, morphological,
and optical properties of titanium dioxide TiO2 thin films before and after annealing, deposited by the ultrasonic spray process, and their photocatalytic applications. To characterize these samples, we use for the structural characterizations: X-Rays Diffractions (XRD), Raman and ATR-FTIR spectroscopy, for the morphological study we use FESEM, and for the optical characterizations, we use the UV-Vis-NIR and photoluminescence spectroscopy. The XRD spectra show that all the samples have a polycrystalline structure with a favorable orientation growth plane (101) which refers to the anatase phase. The crystallite size is severely varied with the PH precursor. Our results confirm that the PH can affect the structure, and Raman spectra enhance these results. The FESEM shows that all the thin films have a homogenous surface, and uniform grain size, without any cracks or pinholes. The ATR-FTIR spectra confirm the successful formation of TiO2 thin film and their good adhesion to the glass substrate. The UV-Vis-NIR shows that our samples have a high transmittance in the visible range of around 85%, and the band gap energy Eg is affected by the PH precursor solution. The photoluminescence allows us to know that the intensity of the peak is related to forbidden band gap purity from defects, when the number of defects between the conduction band and the valence band is fewer, the peaks have a high intensity. The intensity of these peaks is affected by the PH precursor of the solution and annealing temperature. Our TiO2 thin films have the ability to degrade Methyl Orange contaminant, and their photocatalytic activity under simulated solar light irradiation (UV-A) is very high, where the Methyl Orange concentration decreased from 100% to around 1%. The performance of TiO2 thin film can enhance with PH precursor values equal to 2.5 and 10.5 (acidic and basic mediums). |
Sommaire : |
………………………………………………………………………………………….. I
Acknowledgment ……………………………………………………………………………II Contents ……………………………………………………………………………………..III General introduction…………………………………IX Chapter 1 : Overview on Titanium dioxide (TiO2) and thin films I.1. Transparent Conductive Oxides (TCOs) .............. 13 I.1.1. Criteria of choice ..................... 13 I.2.Titanium dioxide .......................... 13 I.2.1. Choice of Titanium dioxide ............. 13 I.2.2. Properties of Titanium dioxide.......... 14 I.2.2.1. Structural properties ................ 14 I.2.2.2. Optical properties ................... 17 I.2.2.3. Electronic properties ................ 18 I.2.2.4. Photocatalytic properties ............ 19 I.3. Thin films ................... 20 I.3.1. Definition of thin film .................... 20 I.3.2. Thin films growth mechanisms and modes .......... 21 I.3.2.1. Thin films growth mechanisms ........... 21 I.3.2.2. Growth modes ............ 21 I.3.3. Applications of TiO2 ................... 22 I.3.3.1. Application in optics .............. 22 I.3.3.2. Application in solar cells (Dye Sensitized Solar Cell) ...... 22 I.3.3.4. Photocatalytic application ................22 I.3.3.5. Photocatalytic hydrogen production............. 22 Chapter 2: Deposition Techniques and characterization methods for thin films IV II.1. Deposition techniques of thin films .......... 25 II.1.1. Choice of a deposition technique ................... 26 II.1.2. Physical deposition techniques ............... 26 II.1.2.1. Pulsed laser ablation technique ......... 26 II.1.2.2. Sputtering technique ............ 27 II.1.3. Chemical techniques ................ 27 II.1.3.1. Sol-gel technique ............... 27 II.1.3.2. Spray pyrolysis technique ................. 28 II.2. Thin films characterization methods ........... 31 II.2.1. structural properties ............................. 31 II.2.1.1.X-ray diffractometer (XRD) method .......... 31 II.2.1.1.1. Crystallite size and dislocation density…………………………………32 II.2.1.1.2. Micro-strain………………………………33 II.2.1.2. Raman spectroscopy method ............... 34 II.2.2. Optical properties .......... 35 II.2.2.1. UV-Vis-NIR method.................... 35 II.2.3. Morphological properties ................. 40 II.2.3.1. Field Emission Scanning electron microscope method ............... 40 II.2.4. Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) spectroscopic me..... 41 II.2.5. Photoluminescence PL method ............... 42 Chapter 3: Preparation, structural, and morphological characterizations of TiO2 thin films III.1. Experimental procedures .................... 44 III.1.1. Choice of deposition substrate .............. 44 III.1.2. Cleaning of the substrates .......... 44 III.1.3. Preparation of the solutions .......... 44 III.1.4. Experimental conditions .......... 45 III.2. Thin films deposition procedure ............. 45 III.3. The effect of PH ......... 46 III.3.1. Preparation of solutions ............. 46 III.4. The effect of annealing ........ 46 III.5. Adhesion test ........ 47 V III.6. Characterizations of TiO2 thin films ............... 48 III.6.1. Thickness of thin films ............. 48 III.6.2. Growth rate of thin films ............... 49 III.6.3. Structural characterization by XRD (X-rays diffraction) ...................................................... 51 III.6.3.1. Crystallite size D and dislocation density δ .............. 52 III.6.3.2. Micro-Strain ( |
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Cote | Support | Localisation | Statut |
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MPHY/636 | Mémoire master | bibliothèque sciences exactes | Consultable |