Preparation and electrochemical properties of polypyrrole/graphite oxide composites with various feed ratios of pyrrole to graphite oxide

Polypyrrole/graphite oxide (PPy/GO) composites are successfully prepared via in situ chemical polymerization with various feed ratios of pyrrole (Py) to graphite oxide (Py:GO = 0.5:1, 1:1, 3:1, 5:1). The electrochemical performance of the composites is determined in a three-electrode cell using cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS) techniques. The relationship between properties of PPy/GO composites and effect of the feed ratio of pyrrole to GO is investigated, and the results indicate that the thermal stability, electrical and electrochemical properties of the composites are strongly influenced by the feed ratios. The electrical conductivities of the PPy/GO composites are 1.27 S cm−1 (Py:GO = 3:1) and 6.25 S cm−1 (Py:GO = 5:1), which are significantly larger than that of pristine PPy and GO. The PPy/GO composites exhibit very high specific capacitance and low charge transfer resistance. Especially, the specific capacitance of the PPy/GO composites (Py:GO = 3:1) reaches 249 F g−1 at discharge current density of 2 mA cm−2, while the charge transfer resistance is only 0.12 Ω. The fabricated PPy/GO composites can be used for the development of new applications for supercapacitor.

► PPy/GO composites are fabricated by in situ chemical polymerization with various feed ratios of pyrrole to graphite oxide.
► The relationship between properties of PPy/GO composites and effect of the feed ratio of pyrrole to GO is investigated in detail.
► The surface of GO sheets is quite uniformly coated with PPy in PPy/GO composites.
► The electrical conductivities of PPy/GO composites are 1.27 S cm−1 (Py:GO = 3:1) and 6.25 S cm−1 (Py:GO = 5:1).