| Conducting polymer has been paid more attention, since scientists found out that doped polymer can exhibit the conductivity which similar to the metal. This kind of material developed rapidly, and applied in many fields. PEDOT and its derivatives have a widely used in solar cell, supercapacitor and sensor with its favorable properties such as good solubility, small size, environmental stability. The conducting polymer/inorganic materials not only can exhibit both organic and inorganic characters but also have new properties with nanometer effect, synergetic or complementary behaviors, which greatly opened up its applications.In this thesis, the hybrid materials were synthesized with PEDOT and its derivative as organic phase, while graphene oxide and WO3 as inorganic phase. The structural and morphological characterizations of the polymer and composites were evaluated by FTIR, UV-vis, X-ray diffraction and FESEM. The electrochemical behaviors of the composites were investigated by galvanostatic charge-discharge,electrochemical impedance spectroscopy(EIS). The electrocatalytic activitives of the composites were examined by cyclic voltammetry and chronoamperometry. The details are summarized as follows:(1) A simple one-step template-free solution method was developed for preparation of PEDOTs with different structure and behavior by adjusting various ratios of oxidant to monomer. The results from structural analysis showed that PEDOT prepared from oxidant/monomer ratio of 3:1 had a higher conjugation length and doping level, and the crystallinity of PEDOT decreased with increasing of oxidant/monomer ratio. The morphological analysis showed that PEDOT(3:1)displayed a special coral like morphology, and the branches of “coral†would adjoin or grow together with increasing content of oxidant in reaction medium, consequently the morphology of PEDOT changed from coral to sheets(at oxidant/monomer ratio of9:1). The electrochemical analysis proved that the PEDOT(3:1) had the lowestresistance and the highest specific capacitances(174 F/g) at a current density of 1 A/g with a capacity retention rate of 74 % over 1500 cycles.(2) Poly(3,4-ethylenedioxythiophene)/graphene oxide(PEDOT/GO) composite was synthesized by a simple template-free solution method. The results from Fourier transform infrared(FTIR) spectroscopy, ultraviolet-visible(UV-vis) absorption spectroscopy showed that a strong interaction between PEDOT and GO occurred in the PEDOT/GO composite, consequently led PEDOT/GO composite had a longer conjugation length and higher oxidation degree than PEDOT. Morphological studies revealed that the composite combines a very well of GO and PEDOT to form a regular and uniform network-like morphology. The PEDOT/GO composite modified electrode was utilized as an electrochemical sensor for the detection of AA. Based on the result of electrochemical impedance spectroscopy(EIS), chronoamperometry and cyclic voltammetry(CV), PEDOT/GO modified electrode exhibited low electrochemical impendance and good electrocatalytic performance towards AA with high sensitivity, wide linear range and good stability. Under the optimized condition,the sensitivity was 47 μA/m M and the linear ranges were 10-1000 μM for AA.(3) A series of poly(3,4-propylenedioxythiophene)/WO3 composites(PProDOT/WO3) were successfully prepared by using hand grinding and ball milling methods, respectively. The effects of WO3 and the synthetic methods on the structure and properties of the composites were deeply discussed. The results showed that the electrochemical behavior of PProDOT/WO3 composites from both methods were higher than respective pure polymer. Moreover, the electrochemical results revealed that PProDOT/WO3 composites from hand grinding method showed higher conjugation and oxidation degree than PProDOT/WO3 composites from ball milling method. Besides, the highest specific capacitance of 267 F/g was obtained in the case of PProDOT/15 wt.%WO3 composite from hand grinding method.(4) Poly(3,4-propylenedioxythiophene)/tungsten trioxide(PPro DOT/WO3)composite was synthesized by a simple solid-state method. The results from Fourier transform infrared(FTIR) spectroscopy, ultraviolet-visible(UV-vis) absorption spectroscopy showed that a strong interaction between PProDOT and nano-WO3 occurred in the composite. X-ray diffraction(XRD) and energy-dispersive X-ray spectroscopy(EDX) analysis proved that WO3 do exist in composite, and the content of tungsten is 42.29 %. Besides, WO3 had no influence on the crystallinity of PProDOT in PProDOT/WO3 composite. Then, the composite was immobilized on the glassy carbon electrode(GCE) and exhibited a significant enhancement of electrocatalytic behavior for iodate reduction. The result validated a good amperometric response toward iodate in the linear concentration range from 5 μM to600 μM with a high sensitivity of 0.079 μA/μM and a low detection limit of 2 μM.(5) The solid-state method was applied for synthesizing poly(3,4-propylenedioxy-2,2’:5’,2"-terthiophene)/WO3(poly(TPT)/WO3) composite with the 15 wt.% content of WO3 in reaction medium. The structure and electrochemical behavior of the composite was discussed. The structural results showed that the oxidation degree and conjugated length of poly(TPT)/WO3 was higher than the polymer. The specific capacitance of poly(TPT) and poly(TPT)/WO3 composite were 170 F/g and 282 F/g, respectively. The results suggested that the electrochemical performance of poly(TPT)/WO3 composite was better than poly(TPT). |
