title: Preparation and photocatalytical performance of TiO2:SiO2 nanocomposites produced by the polymeric precursors method.
abstract: Anatase TiO2 is a promising photocatalyst due to its chemical stability, non-toxic characteristics, notable UV light absorption as well as photo-corrosion resistance and oxidative properties. Surface area and TiO2 dispersion quality are important factors that affect photoactivity of TiO2:SiO2 nanocomposites. In order to improve these factors, TiO2 nanoparticles were immobilized on mesoporous silica substrate through the polymeric precursors method, obtaining the nanocomposites in a simple routine. The TiO2 resin was synthesized by the polymeric precursors method and different resin thickness (0.5; 1.0; 2.0; 3.5; 5.0 nm) on silica were synthesized by calcination during 4 hours at 450 degrees C in pH 1.5. The selected pH for immobilization ensured adhesion of TiO2 nanoparticles onto the silica substrate surface. X-Ray Diffraction patterns indicate that all samples were predominantly anatase phase and immobilization improved surface area. Ametryn kinetic evaluation presents better results for SAM 3.5 and SAM 0.5. The results show that difference in TiO2 loading, surface area and crystallinity of samples are factors that influence photocatalytic efficiency.
authors.affiliation: Department of Materials Engineering, Universidade Federal de São Carlos, Rodovia Washington Luis KM 235 SP-310, São Carlos, São Paulo, CEP 13565-905, Brazil.
authors.forename: Margaret
authors.initials: M
authors.lastname: Dawson
authors.forename: Gabriela Byzynski
authors.initials: GB
authors.lastname: Soares
authors.forename: Caue
authors.initials: C
authors.lastname: Ribeiro
mesh_terms: D002384:Catalysis; D008027:Light; D008422:Materials Testing; D049329:Nanostructures / Q000737:chemistry* / Q000528:radiation effects / Q000648:ultrastructure*; D010316:Particle Size; D010777:Photochemistry / Q000379:methods*; D011108:Polymers / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry* / Q000528:radiation effects; D014025:Titanium / Q000737:chemistry* / Q000528:radiation effects; D014227:Triazines / Q000737:chemistry* / Q000302:isolation & purification / Q000528:radiation effects
chemical_list: D011108:Polymers; D014227:Triazines; C009495:titanium dioxide; C100057:ametryne; D012822:Silicon Dioxide; D014025:Titanium