Sürdürülebilir Yeşil Kampüs Koleksiyonu / Sustainable Green Campus Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7755
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Master Thesis Catalytic Surface Coatings for Household Ovens(Izmir Institute of Technology, 2016) İzer, Alaz; Şeker, Erol; Şeker, ErolThe emission of harmful volatile compounds, such as aldehydes, and also carbon monoxide could occur during cooking processes at home or industry due to the combustion and cracking of spilled vegetable oil on the walls of an oven. It is known that the by-products generated during cooking could affect human health and environment if they are properly vented or removed. To eliminate the health and environmental problems related to oven emission, self-cleaning catalytic materials coated walls for ovens seem to be viable alternative to the toxic and time consuming chemical cleaning solutions. In this project, a sol-gel method and also the dip coating technique was used to produce a catalytic material coated aluminum plates. Specifically, the calcination time and the temperature were studied to better understand the relationship between the textural/chemical properties of the catalyst coated metal plates and their catalytic activities. The studied calcination temperatures were 450°C, 500°C and 550°C whereas the calcination time were 10 min, 30 min and 60 min for each type of catalyst. Aluminum oxide supported nickel and also aluminum oxide - manganese oxide supported nickel catalysts were prepared as the catalyst that were used in coating. The catalytic activities of the catalyst coated plates were determined using canola oil as a function of reaction time which were 1h at 170°C and 200°C. The results have been shown that the most convenient calcination conditions for the canola oil combustion were 500°C for 30 minutes by using aluminum oxide – manganese oxide supported nickel catalyst.Master Thesis Methylene Blue Degradation in Water Using Sol-Gel Made Tio2 Supported Oxide Photocatalysts(Izmir Institute of Technology, 2011) Köseoğlu, Burcu; Şeker, ErolPure TiO2 and Fe3+ doped TiO2 photocatalysts were synthesized by changing H2O/Ti ratio, HCl/Ti ratios and calcination temperatures. Photocatalytic activities of the samples were determined for the degradation of methylene blue. The primary objective of this study is to narrow the band gap energies of the photocatalysts by changing preparation procedure and also doping with Fe3+ ions. Pure TiO2 and Fe3+ doped TiO2 photocatalysts were prepared by the sol-gel method, and also the impregnation method was applied for Fe3+ doping. The characterization of the samples was performed by using XRD and DRS techniques. Photocatalytic activities were measured by using UVvis absorbance. This study shows that the heat treatment directly affected the crystallite size.Generally, crystallite size of the samples increased with calcination temperature and the heat treatment between 700 C and 800 C also resulted in crystalline phase transformation from anatase to rutile. TiO2 samples prepared with H2O/Ti ratio of 4 and HCl/Ti ratio of 0.15 calcined at 700 C and H2O/Ti ratio of 4 and HCl/Ti ratio of 0.45 calcined at 800 C had only rutile phase. Band gap energy is one of the important factors affecting the photocatalytic activities. In this thesis study, band gap energies of the TiO2 samples were calculated using DR spectrums together with Kubelka Munk function. The DRS analyses showed that samples with rutile phase had the smallest band gap energies; in fact, the pure TiO2 samples (H2O/Ti ratio of 4 and HCl/Ti ratio of 0.45 calcined at 900 C) had the minimum band gap energy of 3.019 eV and the maximum photocatalytic conversion of 25% in 10 min and 93% conversion was reached in 15 h. In contrast, photocatalytic conversion decreased with doping with Fe3+ with excessive dissolution of iron ions.