ZIF-8/magadiite layered silicate heterostructure for battery-type supercapacitors

Abstract

By a in situ co-precipitation approach was created a novel heterostructured material by assembling the ZIF-8 zeolitic imidazolate framework on unmodified magadiite layered silicate (Na-MAG). ZIF-8 was successfully associated with the Na-MAG, as demonstrated by the Rietveld refinement, which also revealed the existence of two phases in the heterostructure. In addition to SEM and thermal analysis, ¹³C and ²⁹Si NMR and FT-IR investigations also corroborate the formation of a new compound. Nitrogen adsorption-desorption isotherms indicated a notable increase in surface area to 842 m²/g and enhanced pore volume for the heterostructure, suggesting its potential for enhanced energy storage capabilities. Electrochemical analyses, such as Galvanostatic Charge-Discharge (GCD) tests and Cyclic Voltammetry (CV) studies, indicated a distinct hybrid electrochemical behavior integrating capacitive and Faradaic battery-type processes was identified by the CV study. Based on the GCD curves, the specific charge capacities showed that ZIF-8/Na-MAG outperformed its separate components, particularly at lower current densities, achieving a capacity of 291.3 mAh g⁻¹ at 1 A g⁻¹. Charge balancing calculations and CV curves demonstrated this supercapacitor's balanced and effective functioning, highlighting the potential of these materials in high-performance energy storage applications.