TiO2, nanocrystalline

Oekermann, T. Zhang, D. Yoshida, T. Minoura, H., Electron transport and back reaction in nanocrystalline Tio2 films prepared by hydrothermal crystallization. J. Phys. Chem. B 2004, 108, 2227-2235. 

Briefly, we describe here various steps involved in the preparation of dye-sensitized solar cell. The nanocrystalline TiO2 prepared by depositing TiO2... 

Scheme 1 illustration of the interfacial charge-transfer processes in nanocrystalline dye sensitized solar cell. S, S, and S represents the sensitizer in the ground, oxidized, and excited states, respectively. Visible light absorption by the sensitizer (1) leads to an excited state, followed by electron injection (2) onto the conduction band of TiO2. The oxidized sensitizer (3) is reduced by the I /I redox couple (4). The injected electrons into the conduction band may react either with the oxidized redox couple (5) or with oxidized dye molecule (6). 

Figure 13 Photocurrent action spectra of nanocrystalline TiO2 films sensitized by complexes 22. 56. and 8. The incident photon-to-current conversion efficiency is plotted as a function of wavelength.

The performance of the three sensitizers 22,8 and 56, which contain different degrees of protonation were studied on nanocrystalline TiO2 electrodes [80]. Figure 13 show the photocurrent action spectra obtained with a monolayer of these complexes coated on TiO2 films. 

The photoelectrochemical production of chlorine at nanocrystalline titanium dioxide thin film electrodes exposed to U V light has been reported [96]. In this process, the energy from photons substantially reduces the overpotential required for the chlorine evolution process and therefore less harsh conditions are required. Metal doping of the TiO2 photoelectrocatalyst was explored but found to be not beneficial for this process. In future, this kind of process could be of practical value, in particular, for water treatment and disinfection applications requiring low levels of chlorine. 

Djaoued Y., BadUescu S., Ashrit P.V., Bersani D., Lottici P.P., Brilning R. Low temperature sol-gel preparation of nanocrystalline Ti02 thin films. J. Sol-Gel Sci. Technol. 2002 24 247-254 Doeuff S., Sanchez C. Electrochromic properties of anatase TIO2 films prepared by the sol-gel process. CR Acad. Sci. H 1989 309(6) 531-534 Dornan C.A., Habibi H., Lynam N.R., McCabe I.A. Electrochromic mirrors and devices, Donnelly Corp., WO Patent 95 30 495, 1994... 

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