Preparation And Electrochemical Performance Of Transition Metal Oxide(Mn, Fe) And Its Composites

Electrochemistry is an important technique to solve the current energy and environmental issues and clinical diagnosis problem. For example, research on lithium ion battery can effectively storage the wind energy, solar energy, tidal energy, geothermal energy and other intermittent energy sources. The development of fuel cells can reduce the consumption of oil and other fossil energy. It is a great significance to the development of electrochemical biosensors for the study of small biological molecules function and diagnosis of neural disease. Because the transition metal oxides have high electrochemical activity, they play a wide and important role in electrochemistry. In this paper, Fe3O4 mesoporous cubic synthesized and as a anode material for lithium ion batteries. Expect to obtain an anode material with large capacity and excellent stability for lithium ion batteries. Three dimensional N-doped graphene Mn O composite materials were synthesized, which it is expected with good oxygen reduction catalytic performance. And three dimensional N-doped graphene Mn O composite materials are utilized to construction of high selectivity, high sensitivity of electrochemical sensors. The mainly works are listed as follows:(1) Synthesis of Fe3O4 mesoporous cubic base on Prussian blue structure and the application in lithium ion batteries. Fe3O4 mesoporous cubic is synthesized by pyrolysis process used the structure of the Prussian blue for the template. As a result of the mesoporous structure can provide more ions and electrons channel in the electrochemical process. In addition, mesoporous structure also increased the specific surface area of material, resulting that the material surface has more reactive sites. Support shape cubic structure of Fe3O4 mesoporous cubic can relieve internal stress with volume change during the process of Li+ intercalation/deintercalation, to prevent the material structure destruction and pulverization. Its application has a good stability to the anode materials for lithium ion batteries and the reversible capacity of up to 800 m Ah g-1.(2) Three-dimensional N-doped graphene/Mn O nanoparticle hybrids as high-performance catalyst for oxygen reduction reaction. Three dimensional N-doped graphene/manganese oxide nanocomposites was synthesized by glutaraldehyde and resorcinol assistant crosslinking covalent assembly(3D-N-RGO/Mn O). N-doping can effectively modified on the surface of RGO, makes RGO obtain better electrochemical properties. When three-dimensional N-doped graphene/Mn O nanoparticle composite materials is used in the oxygen reduction reaction, 3D N-doped graphene and Mn O nanoparticles occurred obvious synergistic effect. Obtained excellent oxygen reduction catalytic performance, good stability and anti-jamming and electron transfer number is 3.03.(3) Selective electrochemical detection of dopamine using three-dimensional N-doped graphene/Mn O Composites. Realize simultaneous detection of DA, UA and AA, by using the synergistic catalytic performance of three-dimensional N-doped graphene and Mn O nanoparticles, and different catalytic oxidation potential of DA, UA and AA. Using DPV method to realize the quantitative detection of DA in the presence of UA and obtain the linear range(10 μM to 180 μM) and detection limit(3 μM, S/N=3).