Heterojunction of N/B/RGO and g-C3N4 anchored magnetic ZnFe2O4@ZnO for promoting UV/Vis-induced photo-catalysis and in vitro toxicity studies.

To promote the low photocatalytic efficiency caused by the recombination of electron/hole pairs and widen the photo-response wavelength window, ZnFe2O4@ZnO-N/B/RGO and ZnFe2O4@ZnO-C3N4 ternary heterojunction nanophotocatalysts were designed and successfully prepared through a sol-gel technique. In comparison to bare ZnFe2O4 and ZnO, the ZnFe2O4-ZnO@N/B/RGO and ZnFe2O4@ZnO-C3N4 ternary products showed highly improved photocatalytic properties in the degradation of methyl orange (MO) under ultra-violet (UV) and visible light irradiation. Various physicochemical properties of the photocatalysts were evaluated through field emission scanning electron microscopy (FESEM), energy-dispersive X-ray (EDX) analysis, X-ray diffraction (XRD), UV-visible diffuse reflectance spectroscopy (DRS), Fourier transform infrared spectroscopy (FT-IR), and vibrating sample magnetometer (VSM) techniques. The observations indicated that the ternary heterojuncted ZnFe2O4@ZnO-N/B/RGO absorbs lower energy visible light wavelengths, which is an enhancement in the photocatalytic properties of ZnFe2O4@ZnO loaded on reduced graphene oxide (RGO) nanosheets and graphite-like carbon nitride (g-C3N4). This gives the catalyst photo-Fenton degradation properties.

Utilizing a nanocomposite consisting of zinc ferrite, copper oxide, and gold nanoparticles in the fabrication of a metformin electrochemical sensor supported on a glassy carbon electrode.

The conception and development of a new electrochemical sensor is reported for the detection of metformin (MET). Zinc ferrite and copper oxide nanostructure (ZnFe2O4-CuO) and gold nanoparticles (AuNPs) have been used to prepare a nanocomposite in modifying a glassy carbon electrode (GCE). The unique ZnFe2O4-CuO/Au nanocomposite was applied as a sensor for the determination of traces of MET by some electroanalytical techniques. Experimental parameters affecting the results were investigated and optimized. Under the optimum conditions and at a working potential of 0.85 V (vs. Ag/AgCl/3.0 M KCl), the sensor response is linear in the MET range of 1.0 nmol L-1 to 1.0 µmol L-1 MET. The limit of detection (LOD) is 0.3 nmol L-1 (at an S/N ratio of 3) and the sensitivity is 1.13 µA µmol L-1 cm-2. The sensor was applied to the determination of MET in real samples where it gave acceptable results. Graphical abstract.