Polyaniline with high crystallinity degree: Synthesis, structure, and electrochemical properties

Polyaniline (PANI) with high crystallinity degree was facilely synthesized on the surface of stainless steel net by galvanostatic method. The effect of polymerization current density on the characteristics of morphology and structure had been investigated by field emission scanning electron microscopy (FE-SEM), Fourier transforms infrared (FTIR), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). FE-SEM observations disclosed that PANI was deposited as nanofibers and their diameters decreased with the polymerization current density. FTIR studies revealed that degree of oxidation increased in order PANI-2 < PANI- 6 < PANI-10. XPS measurements displayed that PANI polymerized at 6 mA cm^-2 (PANI-6) exhibited much higher doping level of 77.8%, which favored the conductivity. XRD analysis discovered that the obtained PANI showed high crystallinity degree in which PANI-6 possessed highest crystallinity degree (X_cr) up to 67%. Electrochemical performances of PANI as electrode materials were studied via cyclic voltammetry. The results presented that PANI-6 possessed greater discharge capacity and better reversibility.