One-pot synthesis of ternary polypyrrole–Prussian-blue–graphene-oxide hybrid composite as electrode material for high-performance supercapacitors

A ternary composite of polypyrrole (PPy), Prussian blue (PB), and graphene oxide (GO), PPy–PB–GO, was successfully prepared through spontaneous polymerization of pyrrole and formation of PB nanocubes on GO. The obtained nanocomposite was characterized by transmission electron microscopy, scanning electron microscopy, X-ray diffraction, and Fourier-transform infrared spectroscopy. The results indicate that the PPy-protected PB nanocubes were well dispersed on the GO. Electrochemical testing showed a specific capacitance of 525.4 F g−1 at a current density of 5 A g−1 in the potential range from −0.2 to 0.6 V, obtained in an electrolyte of 1 mol L−1 KNO3 during the galvanostatic charge–discharge cycles, which is superior to the performance of binary cathode materials, including PPy–PB and PPy–GO nanocomposites. The as-prepared supercapacitor could retain a specific capacitance of 96% after 2000 cycles. It was confirmed that the three components—PPy, PB, and GO—led to the display of integrated electrochemical behavior and a resulting capacitor with enhanced performance. The significant enhancement in electrochemical performance of the ternary nanocomposite can be attributed to the synergistic effect of PPy-protected PB nanocubes dispersed on GO sheets with the pseudocapacitance from PB and PPy on the double-layer capacitance from GO.