Graphene oxide-enhanced ZnO@Fe3O4 nanocomposite: Synthesis, characterization, and catalytic performance

• Synthesis of graphene oxide-enhanced ZnO@Fe 3 O 4 nanocomposite with superior properties. • High catalytic efficiency for reducing methylene blue, methyl orange, and 4-nitrophenol. • Positive surface charge enhances antibacterial activity and membrane interaction. • Magnetic Fe 3 O 4 enables easy separation and reusability. • Versatile potential for environmental and biomedical applications. The advancement of efficient and reusable nanomaterials is essential for enhancing reaction kinetics and minimizing energy demands across a wide range of industrial and environmental applications. Among these, magnetically responsive nanostructures offer a significant advantage in terms of facile separation and recovery due to their intrinsic magnetic characteristics. In the present work, a novel magnetic nanocomposite, ZnO@Fe 3 O 4 -GO, was successfully synthesized through a graphene oxide (GO)-assisted fabrication strategy that markedly improved its functional performance in pollutant degradation and microbial inhibition. The engineered nanocomposite consists of a well-defined core-shell architecture, where Fe 3 O 4 forms the superparamagnetic core, uniformly coated with a ZnO shell and embedded between GO layers, which serve to stabilize the structure and enhance dispersion. Comprehensive structural and magnetic analyses were conducted using FESEM, EDX, TGA, XRD, and VSM, confirming the formation and integrity of the composite material. The reactivity of ZnO@Fe 3 O 4 -GO was assessed in the reduction of three common organic pollutants methylene blue, 4-nitrophenol, and methyl orange exhibiting notable reduction rate constants of 0.059 1/s, 0.0297 1/s, and 0.0438 1/s, respectively, with full reduction occurring within 70 to 105 seconds. Owing to its magnetic properties, the material was easily separated from the reaction medium and reused for ten consecutive cycles without a significant loss in activity. Furthermore, the nanocomposite displayed strong antibacterial activity against both Escherichia coli and Staphylococcus aureus , highlighting its potential as a multifunctional agent. Overall, the synthesized ZnO@Fe 3 O 4 -GO nanocomposite demonstrates considerable promise for use in environmental remediation and antimicrobial technologies, combining high efficiency, reusability, and structural robustness.