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-ZnFe 2 O 4 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 (104) in GQDs@PEG@Mg-ZnFe 2 O 4. Moreover, GQDs@PEG@Mg-ZnFe 2 O 4 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-ZnFe 2 O 4 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/cm2 current density, respectively. These results highlight the multifunctional nature of the GQDs@PEG@Mg-ZnFe 2 O 4 nanocomposite and its potential as a versatile material to address challenges in both energy storage and conversion technologies. [Display omitted] • A hybrid electrocatalyst GQDs@PEG@Mg-ZnFe 2 O 4 was synthesized through a facile technique. • The coexistence of graphene quantum dots (GQDs) and polyethylene glycol (PEG) resulted in enhanced dielectric constant of GQDs@PEG@Mg-ZnFe 2 O 4 ternary nanohybrid. • The remarkable capacitive behavior and high cyclic stability of GQDs@PEG@Mg-ZnFe 2 O 4 , indicates its potential as an energy storage material. • The superior OER and HER activity of the ternary nanohybrid, with a lower Tafel slope mak it promising for water electrolysis. • GQDs@PEG@Mg-ZnFe 2 O 4 ternary nanohybrid is a potential candidate for both low-frequency and water-splitting applications. [ABSTRACT FROM AUTHOR]