Preparation and Process Chemistry of SnO2 Films Derived from SnC2O4 by the Aqueous Sol–Gel Method
Abstract:Nanocrystalline SnO2 films were prepared from SnC2O4 by a sol–gel route. A clarified and stable Sn-containing sol was obtained by dissolving and chelating SnC2O4 with C6H8O7 and H2C2O4 in a C6H8O7/triethanolamine (TEA) mixing aqueous solution with a pH of 6.5–7.0. The chelation and condensation reactions were deducted based upon infrared, Raman, and X-ray photoelectron spectra analysis. Results illuminated that a number of ionized-state carboxyl groups and active tin hydrate were produced in the mixing solution by amido association of TEA with H on –COOH of H3L and H2C2O4, supplying a precondition for tin sol formation. X-ray diffraction and field emission scanning electron microscope analysis indicated that SnO2 film had a rutile structure and consisted of nanocrystals with a mean size of about 7 nm. Film thickness could be controlled by the number of dip coating—annealing cycles according to 30–45 nm/cycle for a Sn concentration of 0.25 mol/L.
Document Type: Research Article
Affiliations: Key Laboratory for Advanced Ceramics and Machining Technology of Ministry of Education, School of Materials, Tianjin University, Tianjin 300072, China
Publication date: 2008-06-01