Synthesis Of PANI Nanomaterials And Their Electrochemical Performances

Supercapacitor is a new type of energy storage and supply device lie between traditional capacitor andsecondary battery, which possesses the merits of high power density and long cycling lifetime while theshortage of low energy density, viz. low capacitance relative to secondary battery. Supercapacitor can beclassified into electric double layer (EDL) capacitor and pseudocapacitor. In general pseudocapacitor ownshigher energy density than EDL capacitor, but the redox transformation during charging/dischargingprocess results in worse cycling stability. The combination of EDL capacitive and pseudocapacitivematerials is capable of improving the overall capacitive performance. Polyanilien (PANI) is a commonP-type conductive polymer with high pseudocapacitance. Based on the high pseudocapacitancecharacteristic and the low cycling stability of PANI, in this thesis, we mainly design capacitive materialsfrom the followed two approaches:1, The graphene-PANI composite via chemical grafting to optimize theEDL capacitance and pseudocapacitance.2, The carbonization of PANI to afford nitrogen doped carbonmaterial to enhance the pseudocapacitance with maintaining of high stability of carboneous material. Themain content of this thesis are summarized as follows:(1) a-G-PANI composite was synthesized using amino-graphene as active substrate to induce thechemical bonding and polymerization of aniline onto graphene surface. The pseudocapacitancecharacteristics of PANI, the high conductivity and high surface of graphene, as well as the π-conjugatedconnection renders a specific capacitance of422F/g, showing the synergic effect of the two components onthe overall capacitance of the composite.(2) Porous nitrogen doped carbon materials were synthesized by the carbonization and activation ofPANI fiber. The nitrogen content and capacitance of the materials differ apparently at different activationtemperature. Among them, the sample activated at600oC owns marked pseudocapacitance, a specificcapacitance of273F/g was achieved at1A/g in the voltage range of-1-1V. The sample under800oCactivation exhibits higher degree of carbonization, under cycling measurement at2A/g in voltage range of-1-1V,99.42%capacitance was maintained after1000cycles of charging/discharging tests.(3) Cu2O-Au composite was synthesized by a facile aqueous phase redox reaction by introducing of Auprecursor into mesocrystalline Cu2O hollow nanocubes. The formation of Au nanoparticles improves the electrochemical activity on the oxidation of glucose. The nonenzymic sensor based on the as-preparedCu2O-Au composite offered a high sensitivity (55.89mA/mM), wide linear range (0.5μM~0.5mM withcoefficient of), and low detection limit (2.05μM) and strong anti-interference ability. The Cu2O-Aucomposite can be a potential sensing material for clinical blood glucose determination.