Facile synthesis of self-assembled polyaniline nanorods doped with sulphuric acid for high-performance supercapacitors

Polyaniline (PANI) nanorods have been successfully synthesized via a simple self-assembly method without any surfactant or template. Sulphuric acid (SA) and ammonium persulfate ((NH4)2S2O8) were used as dopant and oxidant, respectively. The morphologies and structures of the PANI-SA with different [SA]/[aniline] molar ratios were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) and X-ray diffraction (XRD). The results indicated that PANI-SA exhibited different morphologies and properties with the change of [SA]/[aniline] molar ratio. PANI-SA with nanorods morphology was obtained with the highest electrical conductivity of 6.65 S cm−1 when the [SA]/[aniline] molar ratio was 10: 1. Cyclic voltammetry (CV) and galvanostatic discharge/charge (GDC) were conducted to evaluate the electrochemical performances. The results showed that these PANI-SA nanorods displayed a specific capacitance of 449.1 F g−1 at 1 A g−1 and a capacitance retention of 75.15% after 1000 cycles at 1 A g−1. The high-performance PANI-SA nanorods pave a way for the production of large-scale, low-cost materials for supercapacitor application.