Authors: D. Fattakhova-Rohlfing, J. Rathousky
Affilation: University of Munich (LMU), Germany
Pages: 468 - 471
Keywords: mesoporous films, tin dioxide, evaporation-induced self-assembly, sol-gel process
We have developed a new facile procedure for manufacturing crystalline thin films of tin oxide with a uniform mesoporous architecture and full crystallinity of the walls. The procedure is based on the evaporation-induced self-assembly of prehydrolyzed tin oxide precursor directed by a commercially available Pluronic polymer. The crucial factor is the formation of a specific oligomeric precursor able to self-assemble into a mesoporous structure, whose formation was triggered by an addition of ammonium hydroxide to an alcoholic solution of tin tetrachloride. The relative concentration of ammonium hydroxide as well as duration and temperature of the hydrolysis reaction influence significantly the properties of hydrolyzed tin oxide species and the mesostructure assembled from them. The films coated from these precursor solutions and calcined at 300 °C to 400 oC exhibit a well-developed worm-like porosity with a wall to wall distance of ca. 18 nm, a surface area of up to 50 cm2/cm2 (corresponding to 55 ± 5 m2/g), and high crystallinity.