Assembly of the photocatalytic membrane having mesoscopic structure

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The effective applications of clean photovoltaic energy has become one of the most important project in the world-wide scale environment and energy problem. Titanium dioxide (TiO_2), a semiconductor with produces electron-hole pair under irradiation, has attracted much attention as a photocatalytic system. One of the promising system is a 2 phased TiO_2-dye sensitized system. Based on theoretical research, materials with mesoscopic structure are found to have the most efficient light energy use. In this present study, various size of small particles were used to fabricate a 2 dimensional highly ordered structure (small particle array) mold. The mesoscopic TiO_2 semiconductor with pthotocatalytic oxidation-reduction ability was used to deal with kinds of environmental problems.These are shown concretely below.1. Fabrication of the highly dense and highly arranged TiO_2 mesoscopic structure by spray pyrolisis method and the characterization of the packing density - The structure was fabr … More icated by spray pyrolisis method while the sol concentration, spraying rate, annealing temperature were controlled. The fabricated structure was observed by use of scanning electron microscopy and the packing condition was characterized by fourier transform.2. Investigation oxidation reduction ability of TiO_2 mesoscopic structure - The reduction ability of fabricated structure examined by silver nitrate has been reported. Therefore, in the present study, only the sustention of the oxidation ability are examined by analyzing the SEM of oxidatively polymerized conducting pyrrole.3. Investigation of meso-hole-size dependent substance decomposition - By changing the size of the photocatalytic reaction site of the structure, the effect of the condensed phase in the oxidation-reduction ability was examined. It was predicated that the decomposited and fabricated substance was different due to the distribution and the thickness of the condensed phase and the charge of nucleic acid, quantitative analysis was performed by using a highly sensitive gas chromatography.4. The selective metal modification on TiO_2 structure - To obtain a high light energy converse efficiency based on the oxidation-reduction reaction, the recombination of electron produced at the oxidation site and hole produced at the reduction site needs to be suppressed. Accordingly, the modification of metal with a similar band to promote electron movement is effective. By applying a vacuum field, the metal will stick only to the spherical reaction site. Therefore, palladium which is commonly used as the metal was examined as a material with separated oxidation and reaction site. Less