Aluminium and nickel-doped zinc oxide thin films fabricated through the aqueous spray-coating method and evaluations of their photocatalytic activities
| dc.contributor.advisor | Hishimore, Philipus | |
| dc.contributor.author | Titus, Wilka N. | |
| dc.date.accessioned | 2026-09-21T13:40:02Z | |
| dc.date.available | 2026-09-21T13:40:02Z | |
| dc.date.issued | 2025 | |
| dc.description | A thesis submitted in fulfilment of the requirements for the Degree of Master of Science in Chemistry | |
| dc.description.abstract | This work introduces the aqueous spray-coating method to address the challenges in the fabrication of thin films for photocatalytic applications. The aqueous spray-coating method has shown to be an effective method for the fabrication of undoped, aluminium (Al), and nickel (Ni)-doped Zinc Oxide (ZnO) thin films on quartz glass substrates with many advantages, such as simple instrumentation set-up, inexpensiveness, the ease of controlling the rate of deposition, and high yield. An aluminium (Al3+) complex salt was synthesised in this study as a source of Al3+ ions in the prepared precursor solutions for fabricating Al-doped ZnO thin films. The synthesised complex was characterised using Fourier transform infrared (FTIR) spectroscopy. The various thin films were fabricated by depositing the prepared aqueous precursor solutions containing Zn2+ complexes alone as well as Zn2+ with varying mole percentages (2, 4, 8, and 16%) of Al3+ or Ni2+ complexes onto pre-heated quartz glass substrates, and the as-sprayed films were heat-treated at 450oC for 30 minutes. The structural, optical, morphological, and photocatalytic characteristics of the fabricated thin films were evaluated using X-ray diffractometer (XRD), ultraviolet–visible (UV–Vis) spectrophotometer and scanning electron microscope (SEM). The XRD results revealed that the fabricated thin films have a hexagonal wurtzite phase. The optical properties (absorbance and transmittance) of the fabricated thin films were analysed using the UV–Vis spectrophotometer, and all the fabricated thin films showed high transmittance in the visible region over 70%, even after Al and Ni doping. Experiments on methyl orange dye degradation in the presence of the fabricated thin films under visible light showed that Al-doped ZnO exhibits good photocatalytic activities that increase with an increase in the doping mole% of Al. On the contrary, Ni-doped ZnO thin films exhibited a very slight to no degradation of the methyl orange dye under the ii same conditions. The highest degradation efficiency was obtained for 8% Al-doped ZnO thin films under visible light irradiation | |
| dc.identifier.uri | http://hdl.handle.net/11070/4291 | |
| dc.language.iso | en | |
| dc.publisher | University of Namibia | |
| dc.subject | Aqueous spray-coating method | |
| dc.subject | Thin films | |
| dc.subject | ZnO | |
| dc.subject | Precursor solutions | |
| dc.subject | Hexagonal wurtzite phase | |
| dc.subject | Photocatalytic activity | |
| dc.subject | Namibia | |
| dc.subject | University of Namibia | |
| dc.title | Aluminium and nickel-doped zinc oxide thin films fabricated through the aqueous spray-coating method and evaluations of their photocatalytic activities | |
| dc.type | Thesis |