Catalytic Activity and Kinetic Studies of Core@Shell Nanostructure NiFe2O4@TiO2 for Photocatalytic Degradation of Methyl Orange Dye

Abstract

Current research focuses on synthesis and characterization of magnetically separable core@shell (NiFe2O4@TiO2) nanostructured photocatalyst with different weight percent (10, 20, 30, and 40) TiO2 using simple wet chemical techniques. Magnetic core with TiO2 shell was synthesized by the hydrolysis of TTIP precursor with NiFe2O4 nanoparticles. NiFe2O4 nanoparticles were synthesized by the sol-gel auto combustion method. The synthesized nanostructures were characterized for structural, morphological and magnetic behavior using XRD, TEM, SEM and VSM while the surface area was calculated using Brunauer-Emmett-Teller analyzer. Pure nickel ferrite was indexed as spinel FCC crystal structure while anatase titania was confirmed from the characteristic peaks in the indexed XRD patterns. SEM images show the uniform particle size and spherical morphology with average size of 18.85 nmand#177;2nm. The Surface area of prepared core@shell nanostructures was found as 258 m2/g for 10 wt. % TiO2 photocatalyst. A decrease in surface area has been observed with the increase in TiO2 percentage. The photo-catalytic degradation of MO was studied using UV-Visible spectroscopy under NiFe2O4-TiO2 catalyst. UV-spectra revealed degradation of methyl orange by the decrease in the characteristic peak at 460 nm. Kinetics of degradation reaction were studied by the integral method of analysis using UV absorbance data at 460 nm. The photo-catalytic activity of as synthesized catalyst was enhanced many folds as compared to the pure nickel ferrite. M-H curves obtained from VSM revealed a decrease in the magnetization of nickel ferrite with a coating of non-magnetic TiO2.