Nanocrystalline F-doped tin dioxide materials: texture, morphology and photosensitization with a perylene-substituted organotin

The controlled hydrolysis of fluoro (2-methylbutan-2-oxy)di(pentan-2,4-dionato)tin followed by annealing at 400-550 degreesC gave conductive mesoporous F-doped SnO2 materials. The materials consist of a porous network of aggregated nanoparticles, the mesoporosity observed corresponding to the interparticle space. Tuning of the annealing temperature enabled us to prepare materials with surface areas ranging from 70 to 150 m(2) g(-1) with an average pore size comprised between 50 and 100 Angstrom and with a mean particle diameter ranging from 50 to 120 Angstrom. Resistivities as low as 1-2 Omega cm were measured for the sample treated at 550 degreesC which contained 2-3 at.% of fluorine. This powder reacted with 3-(6-trihex-1-ynylstannylhexyl)perylene to furnish a dye-sensitized F-doped SnO2 mesoporous materials. An intensity-dependent photocurrent was produced under blue light illumination using the cavity microelectrode (CME) technique. With an aqueous NaBr solution, the photopotential reaches 700 mV, a value slightly higher than that found for an undoped sensitized SnO2 powder (similar to600 mV). (C) 2004 Elsevier B.V. All rights reserved.