Enhanced sunlight-driven photocatalytic, supercapacitor and antibacterial applications based on graphene oxide and magnetite-graphene oxide nanocomposites

Herein, we report an enhanced sunlight-driven photocatalytic, supercapacitor and antibacterial applications based on graphene oxide (GO) and magnetite-graphene oxide (Fe3O4-GO) nanocomposites. The materials were synthesized by the facile chemical precipitation method and examined in detail by various techniques including field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), UV-Visible (UV-Vis.) spectroscopy, Fourier transform infrared (FTIR) spectroscopy and vibrating sample magnetometer (VSM). The effective production of GO and Fe3O4-GO nanocomposite was validated by XRD, while UV-Vis. measurements demonstrated a smaller bandgap for the nanocomposites. The uniform distribution of Fe3O4 nanoparticles over GO nanosheets were observed through FESEM and TEM studies. The prepared materials were further utilized as sun-light driven photocatalyst for the degradation of methylene blue (MB) dye, working electrode for the supercapacitor application and efficient biomaterial to examine the antibacterial characteristics against Gram-positive (S. aureus) and Gram-negative (E. Coli) bacterial strains. As an efficient photocatalyst, the Fe3O4-GO nanocomposites exhibited a rapid degradation (91% in 30 min) for methylene blue dye under direct sunlight irradiation. The synthesized nanocomposite exhibited a maximum specific capacitance of 775 Fg-1 at a current density of 1 Ag-1 and exceptional chemical stability as an electrode material. Antibacterial activities of the synthesized materials were also exhibited against Gram-positive (S. aureus) and Gram-negative (E. coli) bacterial strains.