Design of wrinkled SiO2 @TiO 2 particles for photocatalytic enhancement

MARCHI, MARÍA CLAUDIA; MARTÍNEZ RICCI, MARÍA LUZ; FUENTES, KEYLA M.; ALDABE BILMES, SARA

San Petersburgo

Congreso; XIX INTERNATIONAL SOL-GEL CONFERENCE; 2019

ISGS / ITMO

The application of photocatalysis based on TiO 2 for environmental remediation presents several disadvantages, especially in the separation of the photocatalyst from liquid media. One way to solve this problem is to support TiO 2 nanoparticles (NPs), but TiO 2 ? subtrate interaction may reduce the photocatalytic activity. A strategy to increase the photocatalytic activity of TiO 2 (NPs) supported on SiO2 spheres is to achieve an arrangement of NPs, such that the interaction with photons reaching the photocatalyst is enhanced. This work proposes to increase the photocatalytic activity of TiO2 NPs using as support wrinkled SiO 2 spheres (w-SiO2 ), in a way that the location of TiO 2 NPs leads to layers with variable effective refractive indexes that define the interaction with photons.w-SiO 2 particles (d = 460 ± 50 nm) were synthesized by bi-continuous emulsion method, and TiO 2 NPs (d = 7 ± 2 nm) were further grown by hydrothermal treatment. We designed two w-SiO2 @TiO2 configurations by controlling the accessibility of theTiO 2 NPs to the porous system: HS, where highly dispersed TiO 2 NPs located in a SiO 2 - TiO 2 hybrid shell (~80nm); and TS, where TiO 2 is arranged as a quasi continuos shell (~15nm) of mesoporous TiO 2 on the geometrical surface of w-SiO 2 spherical particles. These configurations are schematized in figure 1. The photocatalytic activity was measured as the photodegradation rate of crystal violet (CV) at pH = 5 under UV-Vis irradiation.