Study On Monolayer Dispersion Binding States Of Sensitization Of Dye On The Surface Of Nanometer-Size TiO₂

The preparation of nanometer-size TiO2 used for electrodes solar cells and dispersions of dyes on its suface were studies based on the important field of dye-sensitized solar cells.The anatase nanometer-size TiO2 colloid was prepared by sol-gel and the grains were obtained by different post-treatment methods. These samples were also characterized by XPS, XRD, TEM testing techniques on crystalline type, particle size, surface structure. The influences of post-treatment method on physical characteristics of nanometer-size TiO2 were investigated.Dispersion of carboxylate dye and sulfonic dye on the surface of nano-TiO2 was prepared by method of impregnation. The surface structure of the samples were characterized by XPS and verified by IR. The results show that 3,4,9,10-perylenetetracarboxylic acid (PA) can disperse on the surface of TiO2 as a monolayer. The respective dispersion thresholds are 0.08gPA/gTiO2. According to the thresholds and the results of XPS and IR investigation, it was suggested that the 3,4,9,10-perylenetetracarboxylic acid is adsorbed on the surface of TiO2 through chelate or bridge bond in the carboxylic group and it's molecules in a upright mode. CoPcTS and CuPcTS can disperse on the surface of TiO2 as a monolayer too. The respective dispersion thresholds are 0.18gCoPcTS/gTiO2 and 0.08gCuPcTS/gTiO2. According to the thresholds and the results of XPS and IR investigation, it was suggested that CoPcTS molecules are adsorbed on the surface of TiO2 in a flat mode while the CuPcTS in an incline one through sulfonic bond.