JAMES, UTIBE ETOP and Covenant University, Theses Masters (2024) GREEN SYNTHESIS AND CHARACTERIZATION OF TITANIUM DIOXIDE-SILICA COMPOSITE ELECTRODE FOR DYE-SENSITIZED SOLAR CELL. Masters thesis, Covenant University.
![[img]](http://eprints.covenantuniversity.edu.ng/style/images/fileicons/application_pdf.png) |
PDF
Download (132kB) |
Abstract
The adverse effects of climate change have necessitated the need for a reduction in traditional synthetic chemicals used for synthesizing useful materials which have been found to impact the environment negatively. Biosynthesis of Titanium dioxide (TiO2) has been gaining scientific attention recently due to its environmentally friendly nature. The unique properties of TiO2 have made it a suitable material for dye-sensitized solar cell (DSSC) electrodes. However, about 4% of solar irradiation under the ultraviolent range gets absorbed due to the large bandgap of TiO2. Since electron-hole pairs can occur for TiO2 at UV light, it is important to extend the light absorption of TiO2 to the visible light by modifying TiO2 with silica. Titanium dioxide (TiO2) was successfully synthesized using aloe vera plant extract at varying concentrations (50, 70, and 100 ml). The silica used for the TiO2-silica composite was produced from rice husk. The synthesised materials were characterized by UV-visible spectroscopy, X-ray diffraction (XRD), Fourier Transform Infrared (FTIR) Spectroscopy, Scanning Electron Microscopy (SEM), X-ray fluorescence (XRF), and Brunauer-Emmett-Teller (BET) Surface Area. The electrochemical method was used to examine the photoactivity of TiO2 and TiO2-silica composite under light and dark conditions. The band gap of as-synthesized TiO2 containing 50, 70, and 100 ml of aloe vera extract was found to be 3.96 eV, 3.99 eV and 3.96 eV respectively. The addition of silica reduced the band gap of TiO2 from 3.96 eV to 3.0 eV. The XRD analysis revealed a pure tetragonal anatase phase of TiO2. The FTIR showed that the absorbance peak at 792.72 cm-1 corresponded to the Ti-O-Ti bond of anatase TiO2 while the Si-O-Si bond for silica was found at 797.7 cm-1. The SEM image shows the needle-like shape of as-synthesized TiO2. The XRF results showed that over 80 wt.% TiO2 was produced, and 94 wt.% of silica was derived from rice husk. The BET surface area of as-synthesized mesoporous TiO2 was found to be 214.34 m2/g while that of silica was 222.83 m2/g. The large surface area obtained for TiO2, and silica will enable the material to absorb photons effectively which would enhance the efficiency of the electrode. The electrochemical results revealed that the TiO2 produced is photoactive. The results obtained suggested that silica has the potential to be used as a solar cell electrode when incorporated with TiO2. This research reveals that aloe vera plant and silica from unutilized rice husk could be explored for energy sustainability which align with the Sustainable Development Goal for affordable and clean energy.
| Item Type: | Thesis (Masters) |
|---|---|
| Uncontrolled Keywords: | Dye-Sensitized Solar Cell, TiO2, Green Synthesis, Composite, Characterization, Electrochemical |
| Subjects: | H Social Sciences > HD Industries. Land use. Labor Q Science > QC Physics |
| Divisions: | Faculty of Engineering, Science and Mathematics > School of Physics |
| Depositing User: | ORIGBOEYEGHA |
| Date Deposited: | 16 Sep 2024 16:23 |
| Last Modified: | 16 Sep 2024 16:23 |
| URI: | http://eprints.covenantuniversity.edu.ng/id/eprint/18420 |
Actions (login required)
 |
View Item |
