Microwave combustion synthesis of tin oxide-decorated silica nanostructure using rice husk template for supercapacitor applications

摘要

Supercapacitors are emerged as leading energy storage device and developing new electrode materials for supercapacitors has received much scientific interest from the researchers. In this study, we have synthesized tin oxide-decorated amorphous silica (SnO_2@RH-SiO_2) nanostructures using rice husk template as a silica source via simple microwave combustion method for supercapacitor applications. XRD, FT-IR, and EDX studies obviously characterize that silica is present in amorphous form along with crystalline SnO_2 having a rutile tetragonal structure in the prepared SnO_2@RH-SiO_2 sample. Further, TEM observation indicates that prepared sample is consisting of amorphous silica nanospheres decorated with agglomerated tin oxide nanoparticles having size of 5-10 nm. Cyclic voltammetry and galvanostatic charge/discharge studies characterize the supercapacitive behavior of working electrode fabricated from prepared SnO_2@RH-SiO_2 nanostructure. The specific capacitances of SnO_2@RH-SiO_2 nanostructure are about 448, 330, 275, 240, 225, and 200 F/g with the current density value of 1, 2, 4, 6, 8, and 10 A/g, respectively. The presence SnO_2 species in SnO_2@RH-SiO_2 nanostructure can provide reactive surfaces for the adsorption/desorption charges and it facilitates the charge storage at the surface of sample. The above results suggested that the prepared SnO_2@RH-SiO_2 nanostructure has potential application for making electrochemical supercapacitors.