| One of the major problems facing human society is the energy and environmental issue. A pivotal approach to solve these problems is the development of new energy such as using the solar energy.1. Noble metal nanostructures have great scattering and absorption area and near-field amplified effect in the case of resonance excitation. These peculiar properties make them be widely applied in photocatalysis, solar cells, sensors,optical modulation, and so on. Since the localized surface plasmon resonance wavelengths can be synthetically tuned from the visible to near-infrared region, Au nanocrystals have attracted much attention. However, sole gold nanocrystals can not have a good effect in some applications. For example, the catalytic activity of gold is weak or no catalytic activity for many chemical reactions. Gold(Au) coupled with other semiconductors can receive surface plasma resonance and other effects. Therefore, we prepared Au nanospheres, Au nanorods and Au@Cu2O core-shell nanostructures, and investigated the optical properties of the surface plasmon resonance and their application in photocatalysis. The results indicated that the direction of the noble metal surface plasmon resonance effect can be controlled by the special structure of noble metal/semiconductor nanocomposites, which was beneficial for better understanding of its role in photocatalytic and solar energy capture. In addition, Au@Cu2O was firstly applied to catalyze the click organic reaction with laser and simulated sunlight irradiation, the yield reached nearly 100%.2. The degradation of organic pollutants by photo-catalytic process has great significance attention in wastewater treatment. Titanium dioxide, as n type semiconductor, was popular investigated in the field of environmental remediation such as waste water treatment due to its strong oxidizing ability, stable chemical properties, nontoxic and high catalytic efficiency. In this thesis, aerosol spray technique was adopted to prepare polythiophene/TiO2 nanocomposite. The performance of the nanocomposites in the degradation of organic pollutants was also studied.3. Biodiesel, as a kind of renewable green energy, is a good alternative to fossil fuel, which can directly replace the existing fossil fuel oil and be applied to the diesel engine. The generation of heterogeneous catalyst, especially the emergence of solid acid and solid base, makes it possible for the biodiesel to achieve large-scale industrial production. SO42-/MxOy solid acid, mainly refers to the metal oxide loaded solid super acid, sulfuric acid groups. The emergence of ordered mesoporous materials provides an alternative opportunity to enhance sulfate catalytic properties of metal oxide solid acid. In this thesis, we adopt a simple controllable and effective NH3/H2 O gas phase induced internal hydrolysis method(VIH) to prepare a solid acid catalyst SO42-/TiO2-SBA-15, which possesses a high-loading and no channel blockage. Such material has ordered mesoporous solid acid, open pore structure, high specific surface area, high acid density and rich active site.These results will help us to solve the energy problem, and make us deeper understand the surface plasmon resonance properties of precious metal/semiconductor. Based on the research about surface plasmon resonance of Au@Cu2O, the bimetallic element of surface plasma resonance can be understood, which has a guiding significance for the use of different resonant modes to realize specific functions. Finally, designing and preparation of titanium dioxide nano-composites provides a new idea to solve the energy and environment problem. |
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