Photodegradation of methylene blue under a new KSr2Nb5O15 nanostructured material

MATOS, J.; LANFREDI, S.; MONTAÑA, R.; NOBRE, M.:
VIII Encontro sobre Aplicações Ambientais de Processos Oxidativos Avançados II Congresso Iberoamericano de Processos Oxidativos Avançados, 3 a 6 de novembro de 2015 – Belo Horizonte – MG – Brasil.

Abstract

The photocatalytic activity of a KSr₂Nb₅O₁₅ nanostructured material was studied using methylene blue as test molecule. The influence of the calcination’s time was also studied. Characterization was performed by FTIR, XRD and SEM. The diffraction line profile and the refinement of the structural parameters of KSr₂Nb₅O₁₅ were obtained from the XRD patterns by the Rietveld method. The sample calcined by 6h seems to be the more photoactive. It has been attributed to the presence of niobium bond with apical oxygen in the [NbO₆] octahedron as suggest the XRD analysis. This apical oxygen is very reactive and can leads to the formation of superoxoradical anions (O₂^0-). The niobate-based materials show low photoactivity, however it can be suggested that they can be potentially used for selective photocatalysts processes.