A Magnetic Reduced Graphene Oxide Nanocomposite: Synthesis, Characterization, and Application for High-Efficiency...

(1) Background: Safety problems associated with aflatoxin B₁ (AFB₁) contamination have always been a major threat to human health. Removing AFB₁ through adsorption is considered an attractive remediation technique. (2) Methods: To produce an adsorbent with a high AFB₁ adsorption efficiency, a magnetic reduced graphene oxide composite (Fe₃O₄@rGO) was synthesized using one-step hydrothermal fabrication. Then, the adsorbent was characterized using a series of techniques, such as SEM, TEM, XRD, FT-IR, VSM, and nitrogen adsorption-desorption analysis. Finally, the effects of this nanocomposite on the nutritional components of treated foods, such as vegetable oil and peanut milk, were also examined. (3) Results: The optimal synthesis conditions for Fe₃O₄@rGO were determined to be 200 °C for 6 h. The synthesis temperature significantly affected the adsorption properties of the prepared material due to its effect on the layered structure of graphene and the loading of Fe₃O₄ nanoparticles. The results of various characterizations illustrated that the surface of Fe₃O₄@rGO had a two-dimensional layered nanostructure with many folds and that Fe₃O₄ nanoparticles were distributed uniformly on the surface of the composite material. Moreover, the results of isotherm, kinetic, and thermodynamic analyses indicated that the adsorption of AFB₁ by Fe₃O₄@rGO conformed to the Langmuir model, with a maximum adsorption capacity of 82.64 mg·g^-1; the rapid and efficient adsorption of AFB₁ occurred mainly through chemical adsorption via a spontaneous endothermic process. When applied to treat vegetable oil and peanut milk, the prepared material minimized the loss of nutrients and thus preserved food quality. (4) Conclusions: The above findings reveal a promising adsorbent, Fe₃O₄@rGO, with favorable properties for AFB₁ adsorption and potential for food safety applications.