Análise das propriedades fotocatalíticas de CdMoO4 dopado com íons de Cálcio obtidos via síntese sonoquímica

Abstract

Among the metallic molybdates, the scheelite-type metallic molybdate photocatalysts stand out, with chemical formula AMoO4 and tetragonal structure, in which A represents bivalent cations, such as Cd, Ca, Pb, Ba e Sr. Currently, they have been much investigated due to their applications as photocatalysts, scintillation detectors and photoluminescent devices. Cadmium molybdate, in particular, is a material of interest because it exhibits excellent optical and electrical performance. Specifically, the photocatalytic and photoluminescent properties are enhanced by doping with others elements. In this sense, this work aimed to synthesize pure cadmium molybdate, CdMoO4, and samples of CdMoO4 doped with different percentagens of Calcium (1%, 2%, 4%, 8% e 16% molar), by the sonochemical method in order to study and compare the photocatalytic activity of samples for removing Methylene Blue dye from water. The sonochemical method used in this work proved to be efficient for obtaining CdMoO4 samples. The optical properties were also investigated in order to relate them with the photocatalytic properties. XRD patterns showed that all diffraction peaks, for all samples, were indexed to a tetragonal phase with the CdMoO4 space group. There was no secondary phase formation, indicating that doping was successful. SEM-FEG micrographs indicated that the samples mainly consist of microspheres that tend to aggregate. The gap energy os the samples varied between 3.6 e 3.7 eV. As for the photocatalytic activity, the sample doped with 2% Calcium showed the best degradation performance against the Methylene Blue dye, degrading 100% of the dye in 100 min of photocatalytic degradation.