Characterization and Photo-catalytic Efficiency of MnFe2O4/Zn2SiO4 for Aniline Degradation Using Box-Behnken Experimental Design and Simulated Solar Radiation

Abstract

In this research, Zn2SiO4 as a support and MnFe2O4 as a main photo-catalyst were individually syn-thesized and MnFe2O4 was fixed on Zn2SiO4 with solid state dispersion method. MnFe2O4 nano pho-to-catalyst was synthesized by co-precipitation method and reflux condition for 12 hours at 85°C in the presence of urea. For identification of catalysts Fourier-transform infrared (FTIR) spectroscopy, Field emission scanning electron microscopy (FESEM), Energy-dispersive X-ray spectroscopy (EDXS), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray fluorescence (XRF) and Brunauer-Emmett-Teller (BET) techniques were used. The size of MnFe2O4 was determined about 15 nm after the fixation on the Zn2SiO4. The photo-catalytic efficiency of MnFe2O4/Zn2SiO4 was checked for degradation of aniline aqueous solu-tion utilizing the irradiation of a 1 kW Xe lamp fitted with the AM1.5 filter (to simulate the solar light spectrum) in the presence of H2O2. Degradation process was modeled and optimized successfully ap-plying response surface methodology (RSM) according to Box-Behnken designs. Experiment results were showed that initial concentration of aniline=5.5 ppm, H2O2 initial concentration=5.3 mM, pH=11 and nano photo-catalyst amount =0.4 g/L are optimal conditions and the degradation effi-ciency in this condition achieved is 96%. In the optimum conditions, arrangement of (MnFe2O4/Zn2SiO4)> (MnFe2O4)> (Zn2SiO4) was obtained for efficiency of photo-catalytic degrada-tion of aniline in aqueous solution. Decomposition kinetic equation determined pseudo first order and k=0.0407.