The Role of Cobalt Ferrites Nanoparticles on Structural and Electrochmical Properties of Mesoporous Silica for Supercapacitor Applications

Abstract

Abstract The research focus in energy storage applications has shifted towards mesoporous silica (MCM-41) material due to its distinct surface, chemical, and electronic properties. However, the electrodes made from mesoporous silica in supercapacitors are unable to meet the growing request for high energy density in electronic devices. To address this limitation, researchers have explored modifying the material with metal oxides, heteroatoms, and conductive polymers, which can provide pseudo-capacitance during charging and discharging processes, thereby enhancing energy density. Among the various materials investigated, ferrite materials, particularly cobalt ferrites (COF), have shown promising electrochemical properties. Nevertheless, their low internal conductivity hinders their usage in supercapacitor applications. Consequently, combining ferrites with MCM-41 has been proposed as a means to enhance the electrochemical behavior. In this study, various contents of COF were loaded on MCM-41. Different characterization methods were used to study the physical and surface properties of the as synthesized materials like XRD, FTIR, SEM, TEM, EDX and SEM-mapping. TEM images confirmed that all the as-synthesized composites retained the mesoporous structure, and the particle size of ferrites ranged from 8 to 14 nm. The cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) techniques were employed to investigate the electrochemical characteristics of the composite materials in H2SO4 electrolyte solution (1.0 M) and a potential window ranging from 0.0 to 0.8 V. The results demonstrated that the incorporation of ferrites onto MCM-41 led to an elevation in specific capacitance, with the highest value (746 F.g-1) observed at 35 COF-MCM-41 composite. However, further increasing the content of ferrites resulted in a decrease in specific capacitance. Furthermore, the prepared composites exhibited excellent cycling stability even after 5000 cycles, with MCM-41, COF, and 35 COF-MCM-41 retaining 84.4%, 89.4%, and 94.8% of their initial specific capacitance, respectively. These findings highlight the significant role played by the dispersion of cobalt ferrite nanoparticles in enhancing pseudocapacitance behavior, thus improving the overall electrochemical performance of the composites.