New Type Of Tio <sub> 2 </ Sub>-based Photocatalyst Preparation And Catalytic Performance Study

The discovery and application of semiconductor-based photocatalytic technology allow the rich, clean solar energy to be effectively transferred to chemical energy, This, provides us an ideal choice in solving the serious environment pollution and energy crisis. Among the hundreds of photocatalysts, TiO 2 has attractted much attention for its many advantages, such as low toxicity, high activity, chemical stability, cheap and free of secondary pollution. Considering that the wide band gap (3.2 eV) of TiO 2 limits its appliaction under ultraviolet light irradiation with a low quantum efficiencies. Lots of efforts have being done to devote on exploring more efficient TiO 2 -based photocatalyst. To dissolve the existed actual problems, both exploring new preparation methods and developing novel visible-light driven photocatalysts were proposed. This thesis mainly focus in the investigation of the relationship between the incorporated hybrid components and photocatalytic properties, and the effect of various preparation methods on the photocatalytic performance. The present thesis are composed of the following three parts:1. Synthesis of Graphite-like Carbon Deposited Anatase TiO 2 Single Crystals as Efficient Visible-Light Photocatalyst sGraphite-like carbon deposited anatase TiO 2 single crystals was prepared by solvothermal treatment. The as-prepared {001} facet exposed single-crystal photocatalysts can be driven by visible-light to degrade organic pollutants. The as-prepared samples were characterized by TEM, FESEM, XRD, DRS, BET, and PL, The effect of the morphologies, compositions, and physicochemical properties on the photocatalytic results have been well discussed. Meanwhile, we also put emphasis on the research of the role graphite-like carbon play in the process of photocatalytic reaction. These photocataly sts exhibited high catalytic activity in both RhB and MO degradation, and the photocatalytic mechanism was also studied.2. Synthesis of mesoporous CdS/TiO 2photocatalyst with core-shell structure using double solovthermal.CdS crystals were incorporated into the solvothermal-induced core-shell mesoporous TiO 2 via pre-adsorbing Cd 2+ catinon and solvothermal treatment. photocatalyst The morphologies and compositions of the CdS/TiO 2 samples were characterized by TEM, FESEM, XRD, DRS, BET, and PL. These results core-shell mesoporous, CdS/TiO 2 samples can be obtained via the proposed route. CdS crystal, serving as inorganic sensitizer, were effectively incorporated into the framework of TiO 2 to extend its light-adsorption edge to visible light region, without destroying the core-shell structure . The promotion effect of the CdS dopants and the high utiliztion efficiency of core-shell structures contributed a high photocatalytic activity to the as-prepared samples in the degradation of RhB.3. In situ synthesis of mesoporous CdS/TiO 2 photocatalyst with core-shell structure.An in-situ synthesis route was proposed to fabricate the core-shell mesoporous CdS/TiO 2 photocatalyst with enhanced interaction between CdS and TiO 2 . Samples with different compositions have been prepared. FESEM, XRD, TEM, BET, DRS and PL were investigate the morphologies, crystal phase, and other physicochemical properties. A possible scheme of the formation process is proposed. Core-shell meosporous CdO/TiO 2 composites were prepared via a solvothermal treatment followed with calcination. Then, CdS were produced via ion-exchange route between CdO embedded in the TiO 2 framework and S 2- sources. These samples show excellent photocatalytic performances in the degradation of both 4-CP and RhB.