Thickness Effect on Photocatalytic Activity of TiO<sub>2</sub> Thin Films Fabricated by Ultrasonic Spray Pyrolysis
In this study, TiO<sub>2</sub> thin films were deposited by ultrasonic spray pyrolysis from solutions with concentrations of 0.1 and 0.2 M. The deposition temperature was adjusted at 350 °C and all samples were annealed at 500 °C for 1 h in air. The thickness of TiO<sub>2</sub&g...
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MDPI AG
2020-09-01
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| author | Ibrahim Dundar Arvo Mere Valdek Mikli Malle Krunks Ilona Oja Acik |
| author_facet | Ibrahim Dundar Arvo Mere Valdek Mikli Malle Krunks Ilona Oja Acik |
| author_sort | Ibrahim Dundar |
| collection | DOAJ |
| description | In this study, TiO<sub>2</sub> thin films were deposited by ultrasonic spray pyrolysis from solutions with concentrations of 0.1 and 0.2 M. The deposition temperature was adjusted at 350 °C and all samples were annealed at 500 °C for 1 h in air. The thickness of TiO<sub>2</sub> films was changed in the range of 50 to ca. 800 nm by varying the number of spray cycles from 1 to 21 and the solution concentration. The results showed that the mean crystallite size of the anatase structure, the surface roughness, and light absorption increased with the film thickness. The effect of film thickness on the photocatalytic activity was investigated with the photodegradation of stearic acid under UV-A irradiation. The optimal thickness of TiO<sub>2</sub> films fabricated by ultrasonic spray pyrolysis for photocatalytic self-cleaning applications was in the range of 170–230 nm, indicating a ca. 2.6 times-higher photocatalytic self-cleaning activity compared to the reference sample, Pilkington Activ<sup>TM</sup>. The photocatalytic results showed that the 190 nm-thick TiO<sub>2</sub> film deposited from the 0.1 M solution applying seven spray cycles exhibited the finest grain structure and maximum photocatalytic activity, leading to 94% of stearic acid degradation in 180 min under UV-A light with the reaction rate constant k = 0.01648 min<sup>−1</sup>. |
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| id | doaj.art-453b467d47e54f6f9ad591dbfad23f82 |
| institution | Directory Open Access Journal |
| issn | 2073-4344 |
| language | English |
| last_indexed | 2024-03-10T16:20:29Z |
| publishDate | 2020-09-01 |
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| spelling | doaj.art-453b467d47e54f6f9ad591dbfad23f822023-11-20T13:43:09ZengMDPI AGCatalysts2073-43442020-09-01109105810.3390/catal10091058Thickness Effect on Photocatalytic Activity of TiO<sub>2</sub> Thin Films Fabricated by Ultrasonic Spray PyrolysisIbrahim Dundar0Arvo Mere1Valdek Mikli2Malle Krunks3Ilona Oja Acik4Department of Materials and Environmental Technology, Laboratory of Thin Film Chemical Technologies Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn, EstoniaDepartment of Materials and Environmental Technology, Laboratory of Thin Film Chemical Technologies Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn, EstoniaLaboratory of Optoelectronic Materials Physics, Department of Materials and Environmental Technology, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn, EstoniaDepartment of Materials and Environmental Technology, Laboratory of Thin Film Chemical Technologies Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn, EstoniaDepartment of Materials and Environmental Technology, Laboratory of Thin Film Chemical Technologies Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn, EstoniaIn this study, TiO<sub>2</sub> thin films were deposited by ultrasonic spray pyrolysis from solutions with concentrations of 0.1 and 0.2 M. The deposition temperature was adjusted at 350 °C and all samples were annealed at 500 °C for 1 h in air. The thickness of TiO<sub>2</sub> films was changed in the range of 50 to ca. 800 nm by varying the number of spray cycles from 1 to 21 and the solution concentration. The results showed that the mean crystallite size of the anatase structure, the surface roughness, and light absorption increased with the film thickness. The effect of film thickness on the photocatalytic activity was investigated with the photodegradation of stearic acid under UV-A irradiation. The optimal thickness of TiO<sub>2</sub> films fabricated by ultrasonic spray pyrolysis for photocatalytic self-cleaning applications was in the range of 170–230 nm, indicating a ca. 2.6 times-higher photocatalytic self-cleaning activity compared to the reference sample, Pilkington Activ<sup>TM</sup>. The photocatalytic results showed that the 190 nm-thick TiO<sub>2</sub> film deposited from the 0.1 M solution applying seven spray cycles exhibited the finest grain structure and maximum photocatalytic activity, leading to 94% of stearic acid degradation in 180 min under UV-A light with the reaction rate constant k = 0.01648 min<sup>−1</sup>.https://www.mdpi.com/2073-4344/10/9/1058TiO<sub>2</sub>thin filmultrasonic spray pyrolysisthickness effectprecursor concentrationphotocatalytic activity |
| spellingShingle | Ibrahim Dundar Arvo Mere Valdek Mikli Malle Krunks Ilona Oja Acik Thickness Effect on Photocatalytic Activity of TiO<sub>2</sub> Thin Films Fabricated by Ultrasonic Spray Pyrolysis Catalysts TiO<sub>2</sub> thin film ultrasonic spray pyrolysis thickness effect precursor concentration photocatalytic activity |
| title | Thickness Effect on Photocatalytic Activity of TiO<sub>2</sub> Thin Films Fabricated by Ultrasonic Spray Pyrolysis |
| title_full | Thickness Effect on Photocatalytic Activity of TiO<sub>2</sub> Thin Films Fabricated by Ultrasonic Spray Pyrolysis |
| title_fullStr | Thickness Effect on Photocatalytic Activity of TiO<sub>2</sub> Thin Films Fabricated by Ultrasonic Spray Pyrolysis |
| title_full_unstemmed | Thickness Effect on Photocatalytic Activity of TiO<sub>2</sub> Thin Films Fabricated by Ultrasonic Spray Pyrolysis |
| title_short | Thickness Effect on Photocatalytic Activity of TiO<sub>2</sub> Thin Films Fabricated by Ultrasonic Spray Pyrolysis |
| title_sort | thickness effect on photocatalytic activity of tio sub 2 sub thin films fabricated by ultrasonic spray pyrolysis |
| topic | TiO<sub>2</sub> thin film ultrasonic spray pyrolysis thickness effect precursor concentration photocatalytic activity |
| url | https://www.mdpi.com/2073-4344/10/9/1058 |
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