| Titanium dioxide is a common semiconductor material. The study and development of TiO2in the field of photocatalytic is earlier and broader. Currently, TiO2is the most widely used photocatalysts materials. In contrast, the development of TiO2semiconductor material in the field of solar energy is relatively much slower. This is because the large band gap of TiO2, resulting in light absorption threshold is in the ultraviolet band, which reduces the efficiency of TiO2in visible light range. Thus expanding the range of the optical absorption and improving the separation rate of photo-generated electron-hole pairs of TiO2has became one of the research focus of the current TiO2photovoltaic materials. In order to improve the utilization of visible light, TiO2were synthesized by hydrothermal method. And the morphology of TiO2was controlled by varying the reaction conditions. Eventually, the TiO2nanorods film structure was synthesized. And the TiO2nanorods film has been sensitized by CdS. These main results are mentioned as below: Nanorods and nanosheets TiO2film were prepared with FTO as substrate and with Hydrochloric acid as hydrolysis inhibitor. The presence of HCl and FTO is a prerequisite for the formation of TiO2nanorods film. Reaction time, HCl concentration and additives affect its morphology. The Scanning electron micrographs results show that:When the reaction time was18h, FTO was completely covered by TiO2without shedding. With the increase of the content of HCl, a small diameter and scatter nanorods film has been found. Continue to increase the amount of HCl, the nanorods lodging phenomenon is obvious, and membrane thinning until the reaction is stopped. The appropriate parameters for preparation of the films are:The reaction time is18h; the amount of butyl titanate is0.33ml; the mass fraction of hydrochloric acid in20.6%. HF additives added lead TiO2nanorods into nano-TiO2sheet structure. Uv-vis and XRD test results show that:TiO2nanorods are Rutile; TiO2nanosheets are Anatase. Cl-and F-played a key role in the formation of rod-like and sheet-like structure.CdS nanoparticles films were prepared by electrochemical deposition method. DMSO mixed with water as the electrolyte solution. CdCl2and thioacetamide were cadmium and sulfur sources, respectively. The Scanning electron micrographs and XRD results show that CdS hexagonal particles transition into spherical particles with the increase of DMSO in the electrolyte. XRD analysis showed that all obtained CdS particles are hexagonal wurtzite structure. With the increasing of H+concentration in solution, production rate of CdS on the electrode became fast. The UV-visible absorption spectra show that absorption edge of CdS films are in the visible region.Using TiO2nanorods film as substrate, CdS sensitized TiO2was prepared by cyclic voltammetry electrodeposition method. And the absorption of visible light was greatly promoted. CdS nanoparticles selectively grew in (002) plane of TiO2nanorods and a Ball-and-stick structure was formed. A possible formation mechanism of the growth of Ball-and-stick structures was discussed. Based on this discussion, it is considered that the TiO2/UV (Ultraviolet light treated TiO2electrode) would yield more CdS nanoparticles than that untreated. Scanning electron micrographs and UV-visible absorption spectra results show that the sensitization rate of TiO2/UV was significantly higher than that of TiO2. In addition, CdS/TiO2/UV showed better electrochemical properties. |
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