Preparation And Investigation Of Properties Of Polyaniline Doped With Transition Metal Ions And MnO₂/PANI

Due to excellent chemical stability, good electrical conductivity, high pseudo-capacitance energy storage characteristic and unique proton doping mechanism, as well as the cheap and easy preparation, polyaniline (PANI) has been become a research focus on the supercapacitor electrode materials in recent years. Polyaniline nanofibers were doped with transition metal ions by chemical or electrochemical method, which can effectively improve the conductivity of polyaniline and then largely improve its capacitance properties, and also exhibited good cycle stability. This article is mainly about synthesis of polyaniline by doped with transition metal ions and recombination with metal oxide. The structure and morphology of samples were characterized and a series of research on the electrochemical properties of polyaniline by doped with transition metal ions and catalytic properties of recombination with metal oxide have been conducted. The main research works are as follows:(1) Doped PANI films were synthesized by cyclic voltammetry on stainless steel mesh substrates in0.2mol·L-1aniline and0.5mol·L-1H2SO4electrolytes with various concentration of transition metal ions (Mn2+, Zn2+, Cu2+). The structure and morphology of doped PANI films were characterized by FT-IR, XRD, SEM, Energy dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) techniques. The electrochemical properties of doped PANI films were investigated by cyclic voltammetry, galvanostatic charge-discharge test and electrochemical impedance spectroscopy in0.5molL-1H2SO4electrolyte. The results suggest that polyaniline doped with different transition metal ions improved its electro-polymerization rate, which were shown in nano-rod structure. Compared with the undoped polyaniline electrode electrochemical performance, doped polyaniline of conductivity and specific capacitance all have increase to a certain extent,(2) Furthermore, PANI doped with Mn2+was synthesized by interfacial polymerization. The structure and morphology of PANI doped with Mn2+were characterized by FT-IR, XRD, SEM techniques. The electrochemical properties of PANI doped with Mn2+were investigated by cyclic voltammetry, galvanostatic charge-discharge test and electrochemical impedance spectroscopy in0.5mol·L-1H2SO4electrolyte. The results suggest that Mn2+have great influence on the morphology of polyaniline, which were shown in short and thick structure of nanorods. The specific capacitance of polyaniline doped with0.4mol·L-1Mn2+was406F·g-1at the current density of5mA·cm-2, which was increased by25%compared with undoped polyaniline and showed small impedance electrochemical reaction. Doped with Mn2+is advantageous to the charge transfer in the charge and discharge process, which improved the electrochemical properties of undoped polyaniline.(3) MnO2/PANI was prepared by adsorption polymerization method, which uses MnO2as the oxidant. The structure and morphology of the composite were characterized by Fourier transform infrared, X-ray diffraction, Scanning electron microscopy. Photocatalytic properties of composite materials in different types of organic dyes were investigated and the catalytic effect was analyzed. The results suggest that PANI was evenly coated in the surface of MnO2nanorods and the photo-catalytic activity of composite was higher than the pure polyaniline and...