Effect of feeding ratios on the structure and electrochemical performance of graphite oxide/polypyrrole nanocomposites

Graphite oxide (GO)/polypyrrole (PPy) nanocomposites (GPYs) were synthesized using in situ polymerization. The effect of the feeding ratios of pyrrole and GO on the structure and electrochemical performances of GPYs was investigated. The structure was characterized via Fourier-transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy and X-ray diffraction. The electrochemical performance was characterized via cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy. The results indicate that the more pyrrole is added to GO (with GO concentrations of 20% and 50%), the more agglomeration of both PPy and GO layers occurs. This is detrimental to the capacitance utilization of PPy. When the feeding ratio of GO:pyrrole is 80:20, PPys with nanofibrils are dispersed homogenously in/on the exfoliated layer of GO and the conductivity is enhanced. The capacitance utilization of PPy in a composite with a GO concentration of 80% (383 F/g) is higher than that of pure PPy (201 F/g), which indicates the presence of a synergistic effect between GO and PPy.