Synthesis, Optical, Electrical And Catalytic Properties Of Titanium-Based Oxides Materials And Their Sodium-Doped Derivatives
| dc.contributor.author | Chew, Ker Yin | |
| dc.date.accessioned | 2017-02-13T01:24:41Z | |
| dc.date.available | 2017-02-13T01:24:41Z | |
| dc.date.issued | 2016-01 | |
| dc.description.abstract | Barium titanate (BaTiO3) and barium nickel titanate (Ba2NiTi5O13) were synthesized via sol-gel method. Mechanism of formation of BaTiO3 and Ba2NiTi5O13 was proposed. The effect of Na doping on structural composition and surface morphology of 3 titanium-based oxides (i.e. titanium dioxide (TiO2), BaTiO3 and Ba2NiTi5O13) were investigated. The phase structures of TiO2, BaTiO3 and Ba2NiTi5O13 i.e. anatase, cubic and monoclinic respectively were sustained after Na doping. This indicates that the substitution of Na on Ti atom was a surface phenomenon. The morphology transformation of Na-doped BaTiO3 particles was observed. Hammett indicator showed that the Na-doped Ba2NiTi5O13 has the highest basicity. From BET result, the Na-doped Ba2NiTi5O13 showed the largest specific surface area as compared to Na-doped BaTiO3 and Na-doped TiO2. The application of these titanium-based oxides as the fillers in polyvinyl alcohol (PVA) was investigated. The structural, thermal, electrical and optical properties of these polymer composites were studied. The x-ray diffraction (XRD) and differential scanning calorimetry (DSC) results showed that the polymer composites were semicrystalline with high amorphous region and low Tg values. The 0.3 mol % of Na-doped of PVA/TiO2, PVA/BaTiO3 and PVA/Ba2NiTi5O13 showed the conductivity of 9.540x10-7, 1.667x10- 7 and 2.401x10-8 S cm-1, respectively. The optical band gaps of PVA based polymer composites showed that they are semiconducting. The optical band gaps were blue shifted when increasing the amount of fillers loading as well as increasing the amount of Na-dopants. The obtained TiO2, BaTiO3 and Ba2NiTi5O13 and their respective Nadoped derivatives were also utilized as heterogeneous catalysts for the transesterification of palm cooking oil. Optimal parameters were 5 wt/v % of catalyst loading, oil to methanol volume ratio of 12:1 and 2 hours of reaction at 150 °C. Amongst the catalysts, Na-doped Ba2NiTi5O13 showed the highest % of methyl esters (ME) yield (96.0 %), whereas TiO2 showed the lowest (76.3 %). The % of methyl ester (ME) yield is attributed to the basicity and pore size of the respective catalysts. | en_US |
| dc.identifier.uri | http://hdl.handle.net/123456789/3708 | |
| dc.language.iso | en | en_US |
| dc.publisher | Universiti Sains Malaysia | en_US |
| dc.subject | Titanium-based oxides | en_US |
| dc.title | Synthesis, Optical, Electrical And Catalytic Properties Of Titanium-Based Oxides Materials And Their Sodium-Doped Derivatives | en_US |
| dc.type | Thesis | en_US |
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