Ferromagnetic xyloglucan–Fe3O4 green nanocomposites: sonochemical synthesis, characterization and application in removal of methylene blue from water

In present study, novel magnetic nanocomposites based on an agro-based material, non-toxic and biocompatible xyloglucan (XG) with magnetic iron oxide (Fe3O4) were synthesized by a simple, safe and ecofriendly sonication method. The synthesized nanocomposites (XG–Fe3O4) were characterized by various analytical techniques such as powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM)-energy dispersive X-ray (EDX), transmission electron microscopy (TEM)–EDX analysis and selected-area electron diffraction (SAED). The average crystallite size of the nanocomposites as estimated by the Scherrer analysis were in the range of 17–20 nm and thus exhibited no significant difference in mean particle size on changing the ratios of Fe3O4 and Xyloglucan. The high resoloution (HR) TEM analysis revealed nanorod like shape of synthesized Fe3O4 nanoparticles. Lattice fringes of the individual crystallites were seen in the HRTEM image, indicative of their good crystallinity. The distance of 0.29 nm was found in between the lattice fringes that confirmed the cubic structure of nanoparticles. The FTIR spectrum of nanocomposite indicated the interaction of functional groups in XG with the Fe3O4 nanoparticles at the surface. The SEM analysis revealed the average crystal size of pure Fe3O4 nanocrystals to be 22.4 nm. The SAED analysis revealed that the nanocomposites (20 nm) were very close to behaving as superparamagnets at room temperature. A preliminary study on removal of methylene blue (MB) dye from aqueous solution indicated that the nanocomposite has potential to be used for photocatalytic and adsorptive removal of MB from aqueous solutions.