MgFe[sub]2O[sub]4/CNTs nanocomposite: synthesis, characterization, and photocatalytic activity

Magnesium ferrite is a visible light absorber, and when combined with multiwall carbon nanotubes (MWCNTs), it can lead to low electron-hole recombination rates, thus improving its photocatalytic activity. In this work, a novel MgFe2O4/CNTs nanocomposite catalyst has been synthesized via anchoring MgFe2O4 nanoparticles onto MWCNTs surface by a sol-gel and microwave-assisted route. The prepared catalyst was characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, scanning and transmission electron microscopy, energy-dispersive X-ray analysis and vibrating scanning magnetometry. MgFe2O4 nanoparticles showed a cubic inverse spinel ferrite structure, while MgFe2O4/CNTs nanohybrids showed combinations of both structures. Morphology studies including Brunauer-Emmett-Teller (BET) analysis confirmed a 40 m2 g-1 specific surface area with narrow mesoporous size distribution for the MgFe2O4/CNTs nanocomposite. The photocatalytic performance of the new catalyst was assessed by photodegradation of methylene blue (MB). The experimental results demonstrated that MgFe2O4/CNTs exhibited strong photocatalytic activity, catalysing the photooxidation of about 98% of MB in 25 min under sunlight.