Layer-by-layer self-assembly of nanostructural TiO2/SiO2

Core-shell type nanostructure TiO2 composite spheres have been fabricated by consecutively assembling of surfactant C12H25SO4Na (SDS) and titanium dioxide nanoparticles, onto SiO2 micro beads and subsequently removing the surfactant by calcinations. A transparent colloidal solution. of extremely fine TiO2 particles from a precursor of tetrabutyl titanate and the technique of layer-by-layer (LBL) self-assembly were used-The morphology, structure and the amount of TiO2 of the composite spheres were studied by SEM, XRD and X-ray energy spectrum. The results reveal that TiO2 nanoparticles were dispersed on the surface of the composite spheres and were of rutile type structure with a spherical shape of about 50 nm in diameter. The surface of the composite spheres is dense and uniform. The content of titania in the composite spheres can be readily controlled by varying the number of the nanoparticle-surfactant deposition cycles.