Magnetically separable, bifunctional catalyst MgFe2O4 obtained by epoxide mediated synthesis

• Rapid synthesis of nanosized MgFe2O4 by epoxide method.
• Efficient catalytic property for oxidation and reduction.
• Super paramagnetic nature facilitates easy separations.

Epoxide mediated sol–gel synthesis of magnesium ferrite (MgFe2O4) starting from MgCl2 and Fe(NO3)3 has been carried out and the product has been subjected to various characterizations such as high resolution powder X-ray diffraction (PXRD), SEM, TEM and HR-TEM with EDX analysis, SAED measurements, FTIR, Raman and UV–visible spectroscopy techniques. Cubic spinel structure emerged on calcining the xerogel (for just 2 h) at temperatures as low as 500 °C with an average crystallite size of 8 nm. Heating xerogel at higher temperatures (700 and 900 °C for the same duration) yielded products with average crystallite size of 27 and 41 nm, respectively. The existence of Mg2+, Fe2+ and Fe3+ in tetrahedral and octahedral sites of the spinel structure have been evidenced from the presence of bands at 211, 322, 470, 541 and 701 cm−1 in the Raman spectrum of the sample. Optical band gap of 1.94 eV has been deduced from UV–visible spectroscopic analysis. MgFe2O4 (obtained at 900 °C) showed a typical super paramagnetic behavior with a saturation magnetization of 22.021 emu/g at room temperature. It showed BET surface area of 21.28 m2/g with an average pore size of 12.19 nm. It was demonstrated to be an efficient catalyst for the oxidation of Xylenol Orange (XO) dye and the reduction of p-nitrophenol to p-aminophenol.

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