Thin Solid Films, Vol.534, 301-307, 2013
Degradation of TiO2 and/or SiO2 hybrid films doped with different cationic dyes
Hybrid thin films, silica-titanium oxides and silica-aluminum oxides, designed based on the sol-gel process are evaluated as catalysts in the photo-degradation of the cationic dyes. Silica matrices from different precursors with various organic functional groups and cross-linked with titanium or aluminum agents (tetraisopropyl orthotitanate and aluminum sec-butoxide) allow the surface property tailoring related to the high capacity of the dye adsorption respective, high photo-degradation activity. The cationic dyes (methylene blue, rhodamine B, crystal violet, malachite green) embedded on the hybrid silica matrix, under ultraviolet light, have a first order kinetics of photodegradation. The cross-linking agents play a key role in the photocatalytic degradation and silicamatrix as dye absorbent. The photo-degradation rate for the binary system derived from methyltriethoxysilane/ vinyltriethoxysilane precursors with both cross linkers showed a significant improvement by comparison with other hybrid materials. The significant increasing in the photodecomposition rate is related to the capacity to generate additional oxidizing species by each silica hybrid compounds. (C) 2013 Elsevier B. V. All rights reserved.