Titania hollow spheres modified with tungstophosphoric acid with visible light absorption for the photodegradation of 4-chlorophenol

MARIA DE LOS ANGELES ORELLANA; LUIS R. PIZZIO; PABLO M ARNAL; LILIAN OSIGLIO

Estraburgo

Congreso; 9TH EUROPEAN MEETING ON SOLAR CHEMISTRY AND PHOTOCATALYSIS: ENVIRONMENTAL APPLICATIONS; 2016

Silica nanospheres coated with TiO2 nanoparticles (SiO2@TiO2) were synthesized. The silica core was removed using a NaOH solution yielding titania hollow spheres (@TiO2). They were subsequently impregnated with tungstophosphoric acid (TPA) solutions. These materials were characterized by several physicochemical techniques (XRD, BET, SEM, TEM, DRS, FT-IR and 31P MAS-NMR). The 31P MAS-NMR and FT-IR characterization revealed that the main specie present in the samples was the [PW12O40]3- anion. The DRS results showed that the absorption threshold onset continuously shifted to the visible region when the TPA concentration increased and with calcination at 500 ° C. The photocatalytic activity in the degradation of 4-chlorophenol aqueous solutions under UV and visible light irradiations increases with the TPA content