A simple approach for the sonochemical synthesis of Fe3O4-guargum nanocomposite and its catalytic reduction of p-nitroaniline

In this present study, a facile and green method to synthesize highly stable Fe3O4-guar gum nanocomposite using ultrasound was reported. Thermal gravimetric analysis, fourier transform infrared spectroscopy, X-ray diffractometry, field emission scanning electron microscopy, energy dispersive spectroscopy, high resolution transmission electron microscopy and X-ray photoelectron spectroscopy were used to characterize the crystal structure, size and morphology, elemental composition, metal metal and metal oxygen bonds of the synthesized nanocomposites. Fe3O4-guar gum nanocomposite with a size of similar to 48 nm was obtained as from TEM. The physicochemical characterization supports the feasibility of guar gum as an efficient stabilizing agent for the formation of nanocomposite; guar gum acts as a capping agent with a zeta potential value of -34.8 which was found to be beneficial for achieving lower particle size. Guar gum serves as a matrix for both reduction and stabilization of nanocomposite. The HR-TEM and XPS shows that Fe3O4 nanoparticles are encapsulated by the guar gum polymeric networks or Fe3O4 guar gum core shell structure. The guar gum encapsulated magnetite nanocomposite has performed better in terms of catalytic activity for the liquid phase reduction of p-nitroaniline. The simple catalytic reduction of p-nitroaniline showed an efficiency of 47% and further exceptional improvement of up to 98% reduction within 60 min with the addition of sodium borohydride was achieved. The sonochemical synthesis of Fe3O4-guar gum nanocomposite does not require stringent experimental conditions or any toxic agents, and thus, a straightforward, rapid, efficient and green method for the fabrication of highly active catalysts for treating environmental pollutants.