凯发

Using improved Hummers method to preparing graphite oxide, then reduced to graphene by chemical and thermal reduction method. The structure, sensitive characteristic and electrochemical performance of product were studied during the oxidation and reduction process. With measurements of XRD, FT-IR, XPS, Raman and so on, results show that: when graphite was oxidized and reduced again, the interplanar spacing d00L along C direction and d100, d110 along a-b direction presented first increasing and then decreasing tendency, and the inserting and sloughing functional groups also presented a certain stage. When the graphite was intercalated and oxidized, abundant oxygen-containing groups can be inserted within the structure layer, while π conjugated structure was damaged and the graphite oxide kept its layer stack structure. The prepared GO with stripping method remained large amounts of oxygen-containing groups within the structure layer without large change, while its structure turned single layer or a few layers. After the GO was reduced, the structure size of graphene decreased, with the oxygen-containing groups decreasing largely and π conjugated structure recovering. Through the sensitive test of H2O, CH3CH2OH, NH3, CH4 and H2, it was showed that the GO and graphene were of good gas-sensing properties, while the gas-sensing properties of GO was better than that of graphene on the whole. The specific capacitance of graphene first increased and then decreased with thermal reduction temperature increasing, the largest specific capacitance was 233.1F/g under 0.5A/g current density. The specific capacity of simple 3D RGO and PANI was 315F/g and 303F/g respectively, while preparing the composite of RGO and PANI by hydrothermal method the 3D RGO/PANI nanocomposites were prepared. The 3D RGO/PANI nanocomposites presented porous mesh structure，and its specific capacitance can be up to 870F/g. Even under big current density (50A/g), its specific capacitance can also remained 250F/g. After 1000 cycle times under 2A/g current density, its capacitance can remain 87%, which indicate a good cycling stability, which can be used as perfect electrode materials in supercapacitors.