The effect of synthesis method on the properties and catalytic activity of Cobalt spinel in Methyl orange degradation
摘要
The effect of synthesis methods (solution combustion and spray pyrolysis) and the nature of chelating agents (citric and tartaric acids) on the characteristics and catalytic performance of nanosized cobalt ferrite CoFe2O4 in reaction of oxidative degradation of methyl orange was systematically investigated. The composition, structure and physicochemical properties of the synthesized spinel nanopowders were characterized by XRD, Mössbauer spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy and BET nitrogen adsorption-desorption method. Single-phase nanocrystalline CoFe2O4 powders with an average size of 14 nm and a high degree of crystal lattice inversion were synthesized via spray pyrolysis as confirmed by Mössbauer spectroscopy data. The nature of chelating agent significantly affected the phase purity of the product, namely, citric acid ensured formation of stoichiometric CoFe2O4, while tartaric acid resulted in iron and cobalt oxides secondary phases formation. Catalytic tests revealed that the materials obtained from both synthesis methods were capable of achieving 99.5–99.7% degradation efficiency of methyl orange through hydrogen peroxide oxidation, following pseudo-first-order kinetics.