Controlling the structural, optical, electrical, and compositional properties of silica-graphite core-shell for...

The graphite-silica (SiO₂@GP) core-shell particles were formed via thermal chemical vapor deposition at 1100 °C. The synthesis's growth times were varied at 1, 5, 10, 30, and 60 min. The properties of SiO₂@GP particles with different growth times were systematically analyzed and investigated. At a growth time of 10 min, major SiO₂ peaks and the principal of the graphene were observed. The SiO₂ particles and thin GP sheets covering their surfaces are clearly observed. An optimized SiO₂@GP structure with a growth time of 10 min (SiO₂@GP-10) was subsequently employed as an electrode in a three-electrode supercapacitor configuration. Electrochemical performance was evaluated using cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy analyses. At a current density of 1 A g^- 1, the SiO₂@GP-10 composite achieved a specific capacitance of approximately 291 F g^- 1 and maintained over 40.14% of its capacitance at higher current densities.