Preparation And Electrochemical Characteristics Of Hierarchical Polyaniline And Its Composites

Polyaniline nanofibers were synthesized by a chemical oxidative polymerization, using ammonium peroxydisulfate as oxidant and p-toluene sulfonic acid as dopant. The capacitive performance of polyaniline nanofiber electrode was investigated. The results showed that micelles played an important role in the formation of polyaniline nanofibers and the electrode showed excellent electrochemical performance with a specific capacitance of 579 Fg"1. The electrode material still maintained a relatively high specific capacity after 1000 cycles which indicated that polyaniline nanofiber electrode had a good cycle stability.Urchin-like hierarchical polyaniline microspheres were synthesized by a simple template-free method in an aqueous solution of ethanol using ammonium peroxydisulfate as oxidant and p-toluene sulfonic acid as dopant. This approach realized the assembly of polyaniline nanofibers from one dimensional to three-dimensional. The morphology and electrochemical properties of polyaniline microspheres were influenced by the concentration of monomer, dopant and oxidant. The electrochemical results showed that polyaniline microspheres electrode possessed good capacitive properties with a specific capacitance of 47 Fg"1 which decreased 20%after 1000 cycles.Polyaniline/manganese dioxide nanocomposite (PANI/MnO2) was prepared by a chemical oxidative polymerization. MnO2 nanorods were synthesized by a hydrothermal reaction and then modified with cetyltrimethylammonium bromide (CTAB) before the polymerization. The resulted PANI/MnO2 nanocomposite was characterized by field emission scanning electron microscopy (FESEM), Fourier transform infrared (FTIR) spectra, X-ray diffraction (XRD) and thermogravimetric (TG) analysis. The results indicated that MnO2 nanorods and polyaniline nanowires interpenetrated to form network structures. The specific capacitance of composite electrode varied with the amount of MnO2 and the maximum is 104 Fg-1 when the mass ratio of An/MnO2 was 1:3 at a current density of lmAcm-2. The electrochemical performance of MnO2 electrode was significantly improved by the introduction of polyaniline.