Electrochemical and dielectric analysis of multifunctional GQDs@PEG@Mg-ZnFe2O4 ternary nanohybrid for low-frequency electronics, water splitting, and sustainable energy storage applications

This work explores the potential of GQDs@PEG@Mg-ZnFe2O4 nanocomposite in water splitting and energy storage applications. The synthesized hybrid showed remarkable dielectric properties indicating its potential for low-frequency telecommunications and electronics applications. The impedance spectroscopy disclosed the contribution of grains and grain boundaries in the realization of colossal permittivity (10(4)) in GQDs@PEG@Mg-ZnFe2O4. Moreover, GQDs@PEG@Mg-ZnFe2O4 showed excellent energy storage performance, indicated by its specific capacitance of 100 Fg(-1) and a retention ratio of 99 % over 1000 cycles at a 1 Ag-1 current density. GQDs@PEG@Mg-ZnFe2O4 nanohybrid also showed remarkable electrocatalytic activity, both for hydrogen evolution reaction and oxygen evolution reaction. The determined Tafel slope value was found to be 90 mVdec(-1) and 110 mVdec(-1) at a 10 mA/cm(2) current density, respectively. These results highlight the multifunctional nature of the GQDs@PEG@Mg-ZnFe2O4 nanocomposite and its potential as a versatile material to address challenges in both energy storage and conversion technologies.