Multifunctional g-C3N4/NixMg1-xFe2O4 nanocomposites: Advanced materials for electrochemical energy storage and biocompatibility

The increasing demand for sustainable energy sources has spurred research into advanced energy storage technologies, with supercapacitors showing significant promise. This research investigates the viability of g-C3N4/NixMg1-xFe2O4 nanocomposites (where x = 0.4 and 0.5) designated NMFG1 and NMFG2 for both electrochemical energy storage and their biocompatibility. Crystalline structures of g-C3N4, NiFe2O4, and MgFe2O4 were confirmed using X-ray diffraction (XRD), revealing average crystallite sizes in the 7-8 nm range. The morphology and elemental distribution of the synthesized materials were examined via field-emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). Energy-dispersive X-ray spectroscopy (EDX) and elemental mapping corroborated the uniform distribution of elements within the nanocomposites. Magnetic analysis revealed superparamagnetic behavior, with an increase in saturation magnetization (Ms) from 3.96 emu/g to 4.47 emu/g. Electrochemical studies highlighted their pseudocapacitive behavior, achieving specific capacitance (Cs) values of 88 Fg(-)(1) and 78.2 Fg(-)(1) for NMFG1 and NMFG2 electrodes, with excellent cyclic stability over 10,000 cycles. Biocompatibility assays demonstrated high cell viability (> 85 %) and insignificant cytotoxicity, confirming their suitability for biomedical applications. These findings position the synthesized nanocomposites as promising candidates for multifunctional applications, including energy storage, and biomedicine.