| Summary: | 碩士 === 國立中興大學 === 化學系所 === 100 === Titanium dioxide (TiO2), due to its low cost, strong oxidizing power, good chemical inertness and great stability, is regarded as a suitable material for various photocatalytic applications. However, a large band gap (3.2 eV) of anatase TiO2 restricts its likelihood to only a narrow ultraviolet region (only ~3–5% of total sunlight). So far, a great challenge that remains is to develop an effective way to produce TiO2 nanomaterials with low band gap.
In this work, chain-network anatase TiO2 nanomaterials with low band gap of 2.73-2.86 were carried out through a hydrothermal treatment of the Ti/TiO2/Ti/FTO substrates. The substrates were prepared by casting TiO2 nanoparticle paste onto a Ti layer which had been sputter-deposited and subsequently casting one more Ti layer on it. Influences of synthetic parameters of hydrothermal temperature, reaction time, alkali concentration, the thickness of the bottom Ti and top Ti layer on the formation of chain-network anatase TiO2 with low band gap were systematically investigated. Various studies such as field emission scattering electron microscope(FE-SEM), X-ray diffraction(XRD), and UV-vis spectrum measurements were conducted. Its corresponding photocatalytic application in methylene blue under xenon arc lamp was performed and shows its enhanced performance. We attribute the enhanced photocatalytic performance of the chain-network anatase TiO2 nanomaterials to low band gap and large specific surface area, which can benefit absorption of visible light and transfer of photogenerated electrons.
|
|---|
