Highly efficient ZnFe2O4 decorated g-C3N4/GO with biomedical and photocatalytic activities

In this work, a novel magnetic composite was synthesized using graphene oxide (GO), graphitic carbon nitride(g-C3N4), and zinc ferrite (ZnFe2O4) for photocatalytic and biomedical functions. The synthesized nanocomposite (g-C3N4/GO/ZnFe2O4) was characterized by Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), field emission scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray (EDX), UV–Vis diffuse reflectance spectra (DRS), vibrating sample magnetometer (VSM), Brunner-Emmett-Teller theory (BET), and photoluminescence (PL) techniques. Decorating g-C3N4 and GO by ZnFe2O4 as a multi-component photocatalyst with a simple and cost-effective method in our work shows high efficiency, antibacterial, and anticancer activity. The outcome of using the nanocomposite as a novel heterojunction structure, in comparison to other individual photocatalysts, has shown great activity in degrading methylene blue (MB) due to the formation of electron-hole pairs. GO improved the photocatalyst adsorption capacity and life of charge carriers, facilitating the transfer of electrons. Also, ZnFe2O4 increased the separate charges and reusability process by making heterojunction structures. The dye degradation process attained 98 % promising efficiency in only 60 min and just 3.7 % degradation after 30 min in dark conditions. The Plausible mechanism shows the Z-scheme route. Also, practical factors such as pH, concentration, dosage, and scavenger were obtained, and the optimal values were 10, 20 mg/L, 0.3 g/L, and EDTA (Ethylenediamine tetraacetic acid), respectively. The reusability of nanocomposite was also analyzed in 6 cycles. Finally, the nanocomposite made the area of inhibition on Pseudomonas aeruginosa (Gram-negative bacteria) and Bacillus cereus (Gram-positive bacteria) about 18 ± 0.5 mm and 14 ± 0.2 mm, respectively. Also, the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) tetrazolium assay was examined. The MTT assay for breast cancer cell lines showed the survival percentage of cells is between 99.2 % and 61.4 %, so it can be applied as a carrier.