Preparation, Characterization And Photovoltaic Properties Of Conducting Polymers-Tatania Self-assembled Nanohybrid Films

Organic-inorganic nanohybrid materials can integrate the merits of inorganic and organic materials at nanometer level, and will be potentially used in the field of mechanics, calorifics, optics, electromagnetics and biology. Inorganic nanoparticles have many particular properties in optics, electricity, magnetism, catalyst and mechanics. Conducting polymers with special structures not only have electrical and optical characteristics as good as those of metal and inorganic semiconductor, but also have flexile mechanical properties of organic polymers, and even have electrochemical activities. Some new differential properties will be gotten when conducting polymers are combined with inorganic nanoparticles. Therefore, it is necessary to fabricate conducting polymer-inorganic nanoparticles hybrid film materials that have special functions.Conducting polymer-inorganic nanoparticles hybrid films can show excellent properties of conducting polymer and inorganic nanoparticles. Maybe, the hybrid films will have new characteristics. Therefore, they have a lot of applications in catalyst, photoelectrical materials, luminescence devices, and so on.In the current dissertation, conducting polymer-titania self-assembled films with interesting photoelectric conversion properties were prepared. By means of the layer-by-layer self-assembly technique (LBL), two kinds of SPAn/TiO₂ nanohybrid ultrathin films were fabricated. One was fabricated with self-doped sulfonated polyaniline (SD-SPAn) and TiO₂ colloidal based on alternately electrostatic adsorption, and another was fabricated with externally-doped sulfonated polyaniline (ED-SPAn) and TiCl₄ in toluene-methanol mixture through the surface sol-gel process. In addition, PPy-TiO₂ nanohybrid film was prepared by in-situ self-assembly technique. The structure and properties of these hybrid films were characterized in detail by UV-Vis, FTIR, and atomic force microscopy, CHI 660 electrochemistry testing system.The experimental results show that both the inorganic and organic components were successfully incorporated into the hybrid films. The characteristic absorbance of the two kinds of SPAn/TiO₂ films increased linearly with the number of bilayers The UV-Vis spectrum also suggests that the size of TiO₂ nanoparticles in the ED-SPAn/TiO₂ LBL films is smaller than that in the SD-SPAn/TiO₂ LBL films. This is consistent with result of AFM.