- Title
- Synthesis, characterization & comparative evaluation of photo-catalytic & antimicrobial activity of Ag2O and TiO2 immobilized on nanofibres for treatment
- Creator
- Gxumisa, Xoliswa
- Subject
- Pollution http://id.loc.gov/authorities/subjects/sh85104530
- Subject
- Titanium dioxide http://id.loc.gov/authorities/subjects/sh85135627
- Subject
- Photocatalysis http://id.loc.gov/authorities/subjects/sh93001301
- Date Issued
- 2014
- Date
- 2014
- Type
- Master's theses
- Type
- text
- Identifier
- http://hdl.handle.net/10353/19545
- Identifier
- vital:43138
- Description
- Water is a very essential substance for the existence of organisms and the environment where it functions as a transport medium for valuable chemicals, minerals, nutrients and also as a reaction medium. However, the remarkable water properties are not just limited to the dissolution of biological valuable substances, but also to harmful entities during pollution. This has led to research in the improvement and development of new techniques for water treatment. In this study, titanium dioxide (TiO2) and silver oxide (Ag2O) were prepared using the sol gel process and precipitation method respectively. The TiO2 was doped using a sol gel process with carbon and nitrogen so as to reduce the band gap. TiO2/Ag2O, N-TiO2/Ag2O and C-TiO2/Ag2O composites were also prepared using a precipitation method. The average particle size of prepared TiO2, C-TiO2, N-TiO2, Ag2O, TiO2/Ag2O, N-TiO2/Ag2O and CTiO2/Ag2O was found to be 13nm, 7nm, 10nm, 23nm, 28nm, 24nm and 21nm respectively as measured by TEM analysis. The photo-catalysts, Ag2O and TiO2 and their composites were immobilized on stabilized nanofibres using the electrospinning process to allow subsequent separation and reconciliation of the photo-catalyst after use in water treatment. The photocatalytic and antimicrobial activities of photo-catalysts were also evaluated using water contaminated with phenol red dye and Escherichia coli. The prepared materials were characterized by XRD, TEM, HRSEM, DRS, EDX, FT-IR, and TGA. Carbon was found to be more effective as a dopant than nitrogen. It reduced the band gap by 0.4 while nitrogen doping showed a reduction in band gap of 0.2 compared to undoped titanium dioxide. The doped TiO2 exhibited higher photo-catalytic and antimicrobial activity than the undoped TiO2. Introduction of Ag2O allowed utilization of visible light by the TiO2- Ag2O nano-composite leading to an improved rate of photo-degradation of phenol red and inactivation of E coli. Photo-catalytic properties showed that carbon doped materials have a higher photo-catalytic activity than nitrogen doped materials, while for antimicrobial v properties it is vice-versa. The immobilization of photo-catalysts on support material made it less effective towards the degradation of phenol red. The rate of photo-oxidation of phenol red was three times faster using powder TiO2 compared to immobilized TiO2. Therefore, this study suggests that photo-catalysis can be used as an effective method for water disinfection and production of potable and pathogen free drinking water even though better methods of immobilization should be sought.
- Description
- Thesis (MSc) (Chemistry) -- University of Fort Hare, 2014
- Format
- computer
- Format
- online resource
- Format
- application/pdf
- Format
- 1 online resource (136 Leaves)
- Format
- Publisher
- University of Fort Hare
- Publisher
- Faculty of Science and Agriculture
- Language
- English
- Rights
- University of Fort Hare
- Rights
- All Rights Reserved
- Rights
- Open Access
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UFH Department of Chemistry
| Thumbnail | File | Description | Size | Format | |||
|---|---|---|---|---|---|---|---|
| View Details Download | SOURCE1 | M Sc (Chemistry) GXUMISA.pdf | 3 MB | Adobe Acrobat PDF | View Details Download |