TiO Preparation And Photocatalytic Mechanism Visible Catalyst Substrate 2

As a comprehensive discipline, semiconductor photocatalysis combines optics,surface chemistry, catalysis chemistry, material science and electrochemistry. Thesemiconductor materials major in absorbing the optical energy and producing thephoto-induced holes and electrons which have strong oxidizability and reducibility aswell, thus the direct and indirect oxidation and reducing reaction can be occurred atthe surface of the catalyst.The discovery and application of semiconductor-based photocatalytictechnology allow the rich, clean solar energy to be effectively transferred to chemicalenergy, This, provides us an ideal choice in solving the serious environment pollutionand energy crisis., TiO₂has attractted much attention for its many advantagesamong the hundreds of photocatalysts, such as low toxicity, high activity, chemicalstability, cheap and free of secondary pollution. Considering that the wide band gap（3.2eV） of TiO₂limits its appliaction under ultraviolet light irradiation with lowquantum efficiencies. Lots of efforts have being done to devote on exploring moreefficient TiO₂-based photocatalyst. To dissolve the existed actual problems, bothexploring new preparation methods and developing novel visible-light drivenphotocatalysts were proposed. The thesis mainly focuses in the investigation of therelationship between the incorporated hybrid components and photocatalyticproperties, and the effect of various preparation methods on the photocatalyticperformance. The present thesis is composed of the following three parts:1. Synthesis of carbon deposited anatase TiO₂with core-shell structure asefficient visible-light photocatalystsCarbon deposited anatase TiO₂core-shell structure was prepared by usingdouble solovthermal treatment. The samples can maintain the core-shell structureand can be driven by visible-light. We study the carbon load, temperature,morphology photocatalytic performance and get the best preparation conditions. Bythe morphology and composition of the synthesized samples were characterized,focusing on both the catalytic results. The as-prepared samples exhibit high catalytic activity in the RhB and chlorophenol degradation, and the photocatalytic mechanismwas also studied.2. Synthesis of Ag/AgBr/TiO₂photocatalyst with core-shell structureAg/AgBr was deposition-precipitation into the solvothermal-induced core-shellmesoporous TiO₂. We study the Ag/AgBr, time, morphology photocatalyticperformance and get the best preparation conditions. The morphologies andcompositions of the Ag/AgBr/TiO₂samples were characterized. The samples canmaintain the core-shell structure and can be driven by visible-light. The surfaceplasmonic resonance （SPR） combines the mult-reflection of light, leading to highphotocatalytic efficiency. The as-prepared samples exhibit powerful catalytic activityin the MO degradation.3. Synthesis of microspheres TiO₂photocatalyst and their visible light catalyticmechanismTiO₂microspheres could be prepared by a straightforward hydrothermalmethod use TiOSO₄and water. This material had high photocatalytic activity undervisible light. We study the sensitization mechanism, the impact of SO42-and oxygenvacancies. The oxygen vacancies of TiO₂surface could necessary for photocatalyticdegradation of organic pollutants. Therefore, it was a good exploration for highvisible light efficiency of TiO₂photocatalysis.