Improved stability in SBA-15 mesoporous materials as catalysts for photo-degradation processes

VERÓNICA ELÍAS; GRISELDA EIMER; RAFAEL OLIVERA; GABRIEL ORLANDO FERRERO

MICROPOROUS AND MESOPOROUS MATERIALS

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2016 vol. 236 p. 218 - 227

1387-1811

SBA-15 materials were modified with Cr, Ni and Fe and characterized by ICP, SAXS, XRD, N2 adsorption,TPR and UVeVis DRS. Their photo-catalytic activity was evaluated for the degradation of Acid Orange 7(AO7) in aqueous suspensions irradiated by artificial UVeVis light. The results showed that the Crmodifiedcatalyst exhibited the highest activity. The presence of Cr6þ highly dispersed on the internalsurface of the SBA-15 structure would be responsible for this observed behavior. Then, when TiO2 wasloaded on this solid, the photo-activity was increased due to a heterojunction effect between the twometals. Moreover, the TiO2 cover resulted in the Cr species protection leading to a notable decrease of theCr leaching into the reaction medium. In addition, comparing with the already reported results formodified MCM-41 catalysts, the solid synthesized here allowed achieving the solution biodegradabilityin shorter irradiation periods and could be re-used even after four cycles without loss of activity. Thus,the high performance of this material leads to make it a very promising photo-catalyst for pre-treatmentof recalcitrant contaminants present in aqueous effluents.