Green Synthesis of Fe3O4/RGO Nanocomposite with Enhanced Photocatalytic Performance for Cr(VI) Reduction, Phenol Degradation, and Antibacterial Activity

Herein, we report a novel single-step hydrothermal synthesis of a photocatalytically stable and magnetically separable g-Fe3O4/RGO nanocomposite in the presence of Averrhoa carambola leaf extract as a natural surfactant for multipurpose water purification application. The Averrhoa carambola leaf extract played a major role in the modification of structural, optical, and electronic properties of the Fe3O4 nanoparticle. At room temperature, the g-Fe3O4/2RGO nanocomposite showed 97% and 76% of Cr­(VI) reduction and phenol degradation, respectively. The higher activity of g-Fe3O4/2RGO was attributed to the in situ loading of RGO, and the synergism developed between RGO and the super magnetic Fe3O4 nanoparticle results in better separation of photoexcited charge carriers (e–/h+) which was concluded from photoluminescence and photocurrent measurements. Further, the g-Fe3O4/2RGO nanocomposite showed better antimicrobial activity against three bacterial pathogens such as Staphylococcus aureous (MTCC-737), Bacillus subtilis (MTCC-736), and Escherichia coli (MTCC-443) compared to GO with respect to a standard antibiotic (30 μg).