Synthesis of wrinkled-SiO 2 @TiO 2 for crystal violet photodegradation.

ROBERTO CANDAL; MARTINEZ RICCI, MARIA LUZ; UBIRAJARA PEREIRA RODRIGUES-FILHO; MARIA CLAUDIA MARCHI; KEYLA FUENTES; AMANDA PERISSINOTTO; SARA ALDABE BILMES

Congreso; SBPMat 2017; 2017

Our work group has recently reported that TiO 2 nanoparticles supported on non-porous SiO 2 spheres exhibit increased activity in the photocatalytic degradation ofcrystal violet due to a light confinement effect, highly favored by the good contrastof refractive indices. On the other hand, mesoporous silica has been widely used inadsorption processes due to their high specific area and pore volume. In thisregard, this work focus in the synthesis of core-shell particles using wrinkledSiO 2 spheres (W-SiO 2 @TiO 2 ) for the crystal violet photodegradation under UV light.The porous SiO 2 spheres were prepared using the bicontinuous microemulsionmethod, while the incorporation of TiO 2 was carried out by hydrothermal treatment.To evaluate the influence of titania location into the porous net, surfactant used assilica pore template was not removed in some cases (not washed systems). Wefound that the presence of surfactant in the unwashed spheres would block theaccess of the TiO 2 precursor to the internal porous net and favoring the formationof a layer. Whereas, the washed SiO 2 spheres does not fully charge with theTiO 2 nominal content and it crystallizes inside the silica pores. The exposed area ofTiO 2 is higher in the first case and consequently the adsorption of the contaminantand its photodegradation is greater. The comparison with non-porous systemsreveals that the core@shell particle prepared with not washed silica spheresresults more efficient for dye removal.