关键词: 聚苯胺, Ag⁺, 比电容, 掺杂

Abstract:

Polyaniline (PANI) is an attractive candidate among the various conductive polymers based on its unique doping/de-doping behavior, intrinsic electrical conductivity, facile synthesis, and environmental stability. However, the poor conductivity and cycle stability in an acid medium have restricted its applications. Our work aims at solving the above problems effectively by doping silver ions into PANI. The PANI and PANI doped with silver ions (PANI/Ag⁺) were synthesized by a facile interfacial polymerization process, which used aniline as a starting material in toluene in contact with an aqueous solution of silver nitrate varied from 0.04 mol•L^-1 to 0.20 mol•L^-1. The as-synthesized PANI and PANI/Ag⁺ were subjected to the physico-chemical characterization by Fourier transform infrared (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) techniques. The electrochemical behaviors of the polymers were studied by cyclic voltammetry (CV), galvanostatic charge-discharge test (CP) and electrochemical impedance spectroscopy (EIS) in 0.5 mol•L^-1 Na₂SO₄ electrolyte. It turned out that the PANI/0.12 mol•L^-1 Ag⁺ showed larger specific capacitance of 529 F•g^-1 and better specific capacitance retention of 51% after 1000 cycles at a current density of 5 mA•cm^-2 compared with those of PANI. The results indicated that the PANI/Ag⁺ is a promising electrode material for supercapacitors.

Key words: polyaniline, silver ions, specific capacitance, doping