The effect of 3-amino benzoic acid linker and the reversal of donor-acceptor pairs on the electrochemical performance and stability of covalently bonded poly(pyrrole) nanotubes

The multiwall carbon nanotubes-polypyrrole (MWCNTs-PPy) composite is a well-known hybrid material suitable for energy storage applications such as capacitors. Since the electrochemical activity, and longterm stability of carbon-PPy systems are critical for their application, we examined the effect of grafting PPy via a 3-ABA linker with MWCNTs with respect to the preference of the donoreacceptor pairs, and furthermore, the durability. X-ray photoelectron spectroscopy studies of C 1s and O 1s signals reveal the electronic interaction between carbon and polymer (pi-pi* stacking), as well as a binding energy shift for C 1s and O 1s carbonyl signals due to the chemical bonding via the electron donating linker and grafted polymer. Cyclic voltammetry and galvanostatic chargeedischarge studies of the capacitor electrode reveal the effect of the reversal doping of the polymer with chloride, as well as the synergy of double layer capacitance (MWCNTs) and pseudo-capacitance of the poly(pyrrole). Impedance spectroscopy studies confirm the improved electrochemical stability for the composite (stable until 1.2 V) in comparison to the bare polymer (degradation at 0.58 V).