Author/Authors :
Zarrin Khame Forosh، M. نويسنده M. Sc. Student, School of Metallurgy and Materials Engineering, Iran University of Science and Technology, P. O. Box: 16846-13114, Tehran, Iran , , Tajer-Kajinebaf، V. نويسنده Assistant Professor, Department of Materials Engineering, Takestan Branch, Islamic Azad University, P. O. Box: 34815-1515, Takestan, Iran. , , SARPOOLAKY، H. نويسنده ,
Abstract :
TiO2-SiO2 core-shell particles with monodisperse silica core and nanostructured titania shell were synthesized by a multi-step coating process. The monodisperse silica spheres were prepared by St?ber method and titania shell obtained from a colloidal sol prepared by a hydrolysis–condensation reaction. The titania sol was deposited on monodisperse silica spheres by a multi-step coating method based on electrostatic attraction. Characterization was performed by DLS, SEM, DTA-TG, FT-IR and XRD. Also, the photoactivity of the core-shell particles was evaluated using methyl orange degradation by UV–visible spectrophotometer. The mean particle size of the colloidal titania sol was determined about 20 nm. The particle size of TiO2-SiO2 core-shell was about 500 nm. The deposit of titania nanoparticles on silica spheres was caused to delay anatase-rutile transformation. The core-shell particles calcined at 650°C showed a higher photocatalytic activity than that of pure titania.
