Synthesis And Properties Of Graphene Oxide/Manganese Oxide/Polyaniline Composites

Carbon, manganese oxide and polyaniline are three kinds of commonly used materials for supercapacitors. In this thesis, a ternary nanocomposite of graphene oxide (GO)/manganese oxide/polyaniline (PANI)(GOM) was prepared by soft chemical methods, and its reduced composites obtained under different conditions were studied. Fourier transform infrared spectrometer (FT-IR), energy dispersive spectrometer (EDS), X-ray diffraction analyzer (XRD), Raman spectrum analyzer (Raman) and transmission electron microscopy (TEM) were used to analyze the microstructure and morphology of the composite materials. Electrochemical workstation and Land battery system were used for testing electrochemical properties. The main results are as follows:(1) A graphene oxide/manganese oxide/polyaniline ternary composite was prepared at room temperature by one-step method, using KMnO4as the oxidant, aniline as reducing agent. The microstructure of ternary composite is sheet-like. It showed good electrochemical performance with the specific capacitance of about323.8F·g-1and the capacitance retain proportion is nearly76%after600cycles.(2) Three ternary nanocomposites of RGOM were obtained under hydrothermal and normal pressure conditions at90℃using4M and8M NaOH. The manganese oxides in three composites showed one dimensional nanofiber structures in different degrees. The result showed that the harsh reaction conditions (such as hydrothermal method or high concentration of alkali) are favorable for the formation of the nanofiber structure. Among three reduced composites, the highest specific capacitance is about333.8F·g-1and the capacitance retain proportion is nearly73%after850cycles.(3) RGOM4with the smooth nanofiber-like structure was prepared by the treatment using4M NaOH at120℃. While RGOM5obtained using8M NaOH showed a rough and sheathed nanofiber-like structure. The composites exhibited great electrochemical performance due to the specific nanostructure. The specific capacitance of RGOM5is about343.8F·g-1. The capacitance retain proportion is nearly100%after800cycles, indicating high stability of this electrode material. RGOM5is a good candidate for surpercapacitor electrode materials.