Room-temperature synthesis of tin oxide nanoparticles using gallic acid monohydrate for symmetrical supercapacitor application

Abstract

Tin oxide (SnO2) nanoparticles were synthesized using gallic acid monohydrate as a reducing agent via precipitation method at room temperature. The synthesized SnO2 nanoparticles (S-SnO2NPs) were characterized by X-ray diffraction (XRD), Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Energy dispersive x-ray (EDX) and Field emission gun scanning electron microscope (FEG-SEM). The results showed the formation of a tetragonal rutile crystal of spherical shape SnO2 nanoparticles with an average size of 20.40 nm. XPS analysis confirmed the oxidation state of Sn4+ with an energy gap of 8.5 eV. The electrochemical properties of S-SnO2NPs were coated on the electrochemically treated carbon cloth (S-SnO2NPs@ETCC) electrode were compared with the commercial SnO2 nanoparticles (C-SnO2NPs@ETCC) electrode. The electrochemical measurement displayed maximum specific capacitance of 523 F/g and 482 F/g for S-SnO2NPs@ETCC and C-SnO2NPs@ETCC electrodes at a scan rate of 5 mV/s in 1 M H2SO4 electrolyte, respectively. Further, the assembled symmetrical supercapacitor (SS) exhibited a specific capacitance of 156 F/g at a scan rate of 5 mV/s and a capacitance retention rate of 94.7% after 5000 cycles at a current density of 20 A/g for total mass loading of 10 mg cm−2 in hydrogel polymer electrolyte (PVA-H2SO4).