Revista CENIC Ciencias Químicas (Feb 2022)
Removal of Methyl Violet from Aqueous solutions using
Abstract
Three members of the A-site doped Nb perovskites with general formula Sr2CaNbO5.5, Sr3NbO5.5 and BaSr2NbO5.5 were synthesised by solid-state methods and their removal efficiency of Methyl violet from aqueous solutions investigated. The X-ray diffraction measurements demonstrated that the three samples have a faced cubic perovskite-type structure in space group Fmm. The additions of Ba2+ and Ca2+ into the A-site of Sr3NbO5.5 have influenced the cell volume, crystal size and density. Subsequently, the removal capacity was also impacted. The crystallite size of the three oxides was calculated to be less than 82 nm. The maximum removal capacities of Methyl violet are found to be 46.5, 13.1 and 8.0 mg/g using BaSr2NbO5.5, Sr3NbO5.5 and CaSr2NbO5.5, respectively. The amounts of the adsorbed dye have decreased as the ionic radii of the doped decreased. The removals of Methyl violet have a positive relationship with pH, temperature and the mass of the oxides.