Magnetite nanoparticle decorated reduced graphene oxide for adsorptive removal of crystal violet and antifungal activities.

This work reports the synthesis and application of magnetic rGO/FeO NCs using a pod extract of L. as areducing agent. GO was synthesized by a modified Hummers method, however GO was reduced using the plant extract to produce rGO. The as-synthesized rGO/FeO NCs were characterized by UV-vis spectrophotometer, Fourier transform infrared (FT-IR) spectroscopy, FT-Raman spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy supported with energy dispersed X-ray spectroscopy (FESEM-EDX), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). The synthesis of magnetic rGO/FeO NCs was confirmed from characterization results of FT-Raman, TEM and VSM. The FT-Raman results showed the D and G bands at 1306.92 cm and 1591 cm due to rGO and a peak at around 589 cm due to FeO NPs that were anchored on rGO sheets; TEM results showed the synthesis of FeO with an average particle size of 8.86 nm anchored on the surface of rGO sheets. The VSM result confirmed the superparamagnetic properties of the rGO/FeO NCs with a saturation magnetization of 42 emu g. The adsorption capacity of rGO/FeO NCs towards crystal violet (CV) dye was calculated to be 62 mg g. The dye removal behavior fitted well with the Freundlich isotherm and the pseudo-second-order kinetic model implies possible chemisorption. Besides, rGO/FeO NCs showed antifungal activities against and by agar-well diffusion method with a zone inhibition of 24 mm and 21 mm, respectively. Therefore, rGO/FeO NCs can be used as an excellent adsorbent to remove organic dye pollutants and kill pathogens.