Zaharuddin, Norhafizah (2024) Effect of Degussa addition and Ag contents on the characteristic and photocatalytic performance of Ag-TiO2 coating deposited on ceramic tiles. Doctoral thesis, Universiti Teknikal Malaysia Melaka.
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Effect of Degussa addition and Ag contents on the characteristic and photocatalytic performance of Ag-TiO2 coating deposited on ceramic tiles.pdf - Submitted Version Download (767kB) |
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Effect of Degussa addition and Ag contents on the characteristic and photocatalytic performance of Ag-TiO2 coating deposited on ceramic tiles.pdf Download (2MB) |
Abstract
TiO2 coating has drawn great attention in various field of application including the ceramic industry. The limitation of TiO2 photocatalytic activity that only reacts on short-wavelength ultraviolet irradiation has brought an effort to extend its potential to visible range by reducing the fast rate of electron-hole pair recombination. Hence, doping with semiconductor such as silver (Ag) incorporated TiO2 is proposed. However, Ag incorporated TiO2 had some issues where the use of Ag with high concentration decreases the surface charge that can cause an agglomeration of Ag species and reduction to Agº particles on TiO2 surface. Lowering the amount of Ag concentration thereafter contributed to the formation of AgO, Ag2O and Agº. The amount of Ag that can control the particles size, surface area, thermal stability and band gap that contributes towards good photocatalytic performance is still vague and continuously studied. Yet, the works of Ag-TiO2 coating reported mostly on the surface of glass, metal and fabric instead of ceramic surfaces. Therefore, in this study, the deposition of Ag-TiO2 coating was carried out on unglazed and glazed ceramic tiles. Firstly, the effect of Degussa P25 on the Ag-TiO2 coating was studied to decide the needs of Degussa P25 in synthesizing Ag-TiO2 sol formulation. Later, the effect of Ag content (2.5, 5.0 and 7.5 mol %) on the microstructure (crystalline phase, crystal size, elemental distribution, morphology and cross section surface) of the Ag-TiO2 coated ceramic tiles (unglazed and glazed) were examined and its photocatalytic performance were tested. This yield to the self-cleaning properties of the intended antibacterial ceramic tiles application. The coatings were heat treated at 500 ºC and characterized by Glancing angle X-ray diffraction (GAXRD) and Scanning electron microscopy (SEM), Field electron scanning microscopy (FESEM) coupled Energy-Dispersive X-ray Spectrometer (EDX) and further tested for environmental application using methylene blue degradation (MB) under ultraviolet (UV) and visible light irradiation. The results of the present study suggest that Ag-TiO2 sol can be synthesized without the aid of Degussa P25 where Degussa P25 possibly hinders the formation of Ag metallic. Ag-TiO2 coating deposited on the unglazed tile was observed sip into the pores of ceramic surfaces. The finding highlights that Ag-TiO2 coating deposited on unglazed and glazed improved photocatalytic performances at 5.0 mol % Ag content under visible light irradiation. This is because 5.0 mol % Ag content presented uneven small density of cracks over the surface with more Ag demonstrated by surface morphology and elemental mapping. Also, it can berelated to their active crystallites that react well upon visible irradiation. Hence it can be deduced that the amount of Ag needed for good photocatalytic performance needs to take into account the substrate and surrounding condition.
| Item Type: | Thesis (Doctoral) |
|---|---|
| Uncontrolled Keywords: | Ceramic industry, Semiconductor doping, Photocatalytic activity |
| Divisions: | Library > Tesis > FTKIP |
| Depositing User: | Muhamad Hafeez Zainudin |
| Date Deposited: | 17 Mar 2025 12:55 |
| Last Modified: | 17 Mar 2025 12:55 |
| URI: | http://eprints.utem.edu.my/id/eprint/28620 |
| Statistic Details: | View Download Statistic |
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