Enhanced electrocapacitive performance and high power density of polypyrrole/graphene oxide nanocomposites prepared at reduced temperature

Abstract

An attempt was made to investigate the effect of the preparation temperature on the electrocapacitive performance of polypyrrole (PPY)/graphene oxide (GO) nanocomposites (PNCs). For this purpose, a series of PNCs were prepared at various temperatures by the cetyltrimethylammonium bromide-assisted dilute-solution polymerization of pyrrole in presence of GO (wt%) ranging from 1.0 to 4.0 with ferric chloride as an oxidant. The formation of the PNCs was ascertained through Fourier-transform infrared spectrometry, X-ray diffraction spectra, scanning electron microscopy and simultaneous thermogravimetric-differential scanning calorimetry. The electrocapacitive performance of the electrodes derived from sulphonated polysulphone-bound PNCs was evaluated through cyclic voltammetry with reference to Ag/AgCl at a scan rate (V/s) ranging from 0.2 and 0.001 in potassium hydroxide (1.0 M). The incorporation of GO into the PPY matrix at a reduced temperature has a pronounced effect on the electrocapacitive performance of PNCs. Under identical scan rates (0.001 V/s), PNCs prepared at <TEX>$10{\pm}1^{\circ}C$</TEX> render improved specific conductivity (526.33 F/g) and power density (731.19 W/Kg) values compared to those prepared at <TEX>$30{\pm}1^{\circ}C$</TEX> (217.69 F/g, 279.43 W/Kg). PNCs prepared at <TEX>$10{\pm}1^{\circ}C$</TEX> rendered a capacitive retention rate of ~96% during the first 500 cycles. This indicates the excellent cyclic stability of the PNCs prepared at reduced temperatures for supercapacitor applications.