抄録
TiO2-thin-films have remarkable properties as a photocatalyst to resolve organic pollutants and an electron transporter with high energy transformation efficiency for dye-sensitized solar cells. For these applications, it is required that thin film has no apparent cracks or has high optical transparency. In this study, TiO2-nanoparticles are synthesized and are deposited using the electrophoresis deposition method. TiO2-nanoparticles can transport electrons by oriented attachment mechanism. Many of nanoparticles were connected with each other and formed nanowires clusters. The lengths of observed TiO2-nanowires were not the same. All of nanowires were positively charged in colloidal aqueous solution and were attracted toward ITO glass as the negative electrode, and then thin film was deposited on it. The crystal structure of thin film was anatase-type. TiO2-nanowires thin film with high optical transparency was deposited. A number of cracks, however, were observed as the deposition time increased and thin film was flaked off from substrate. TiO2-thin films with no cracks could be deposited using mixture of TiO2-nanowires and TiO2-nanoparticles (P25). It was suggested that single nanowires were mainly deposited at ITO glass at the first stage of electrophoresis, nanowire-cluster at the second stage and then finally P25 were deposited.
