Organic sulfate modified carbon nantube/polypyrrole core-shell nanocomposites with improved electrochemical performance

• Two organic sulfates were used as both modifier and dopants of CNT/PPy composites.
• The core-shell structure can be tuned by changing the molar ratio of AQDS to NDA.
• The formation of AQDS-NDA hybrids favored the formation of PPy on MWCNTs surface.
• ANCP0.4 displayed a high specific capacitance and ideal capacitor like behavior.

In this study, two organic sulfates, naphthalene-1,5-disulfonic acid (NDA) and/or anthraquinone-2,6-disulfonic acid disodium salt (AQDS), were used as both modifier as well as dopants of carbon nanotube/polypyrrole composites. The core-shell structure of the composites can be controlled by changing the molar ratio of AQDS to NDA. Among all the composites, ANCP0.4 (the molar ratio of AQDS/NDA is 0.4) provided a uniform coating layer of PPy, the thickness of the PPy layer is about 30–50 nm. The probable formation mechanism for the core-shell structure of the ANCP0.4 was proposed. The formation of AQDS-NDA hybrids favored the formation of PPy on the surface of MWCNTs. Electrochemical performances showed that ANCP0.4 obtained high specific capacitance as well as ideal capacitive behavior.