Studies On Solid-state Synthesis And Properties Of The Polythiophene Derivatives/ZnO Composites

With the rapid development of technology, more and more attention fouces onstudy of the conducting polymer materials. And there has been appeared varity ofconducting polymers with accelent mechanical poroperties, which greatly opened upits applications. Among these conducting polymers, polythiophene and its derivativeshas a great application in electronic and nanoelectronic divices with its favorableproperities such as small size, good solubility, environmental stability, and good lightemitting. In recent years, the conducting polymer/inorganic nanomaterials have beenextensively development to obtain new kind of composite materials with synergetic orcomplementary behaviors, and be used in verity of field, because of it has many of thecharacteristics of organic and inorganic materials.In this paper, a verity of hybrid materials were prepared by solid-state methodwith the thiophene type conductiing polymers as organic phase, while the nano-ZnOas inorganic phase. The structural and morphological properties of the compositeswere investigated by FTIR, UV–vis, X-ray diffraction and TEM. The electrochemicalperformances of the composites were investigated by galvanostatic charge-discharge,cyclic voltammetry and electrochemical impedance spectroscopy (EIS). And thephotocatalytic activities of the composites were examined through the degradationprocesses of a methylene blue (MB) solution under UV light irradiation. The detailsare summarized as follows:(1) poly(3,4-propylenedioxythiophene)/Zinc Oxide composites (PProDOT/ZnO)were synthesized by solid-state oxidative polymerization method. The results fromFTIR and UV-vis spectra showed that the PProDOT/ZnO composites weresuccessfully synthesized by solid-state method, and nano-ZnO had great influences onthe conjugation length and oxidation degree of the polymers. Furthermore, thePProDOT/5wt%ZnO had the highest conjugation and oxidation degree among thecomposites. The XRD analysis indicated the content of ZnO had no effect ondiffraction pattern of PProDOT. Morphological studies revealed that all thecomposites displayed an irregular sponge like morphology. The electrochemical testsshowed that the PProDOT/5wt%ZnO had a higher electrochemical activity with a specific capacitance value of220F.g1than others. The results from photocatalyticactivities of the composites indicated that the PProDOT/5wt%ZnO had betterphotocatalytic activity than other composites.(2) The solid-state method was applied for synthesizing PTET/ZnO,PTPT/ZnOand PTMPT/ZnO composites with the5wt%content of nano-ZnO in reaction medium.FTIR and UV-vis showed that the structural feature of polymer and addition ofnano-ZnO could strong effect on Oxidation and conjugation degree of the composites.Comparative result showed that the poly (TET)/ZnO composite had high oxidationand conjugation degree as well as more stable planar structure than other composites.Electrochemical tests proved that the (TET)/ZnO had higher electrochemical activitywith a specific capacitance value of195F.g1than others(3) PEDOT/ZnO nanocomposites in powder form with the different content ofZnO were prepared by a simple solid-state heating method. The results confirmed thatthe ZnO nanoparticles were successfully incorporated in the PEDOT matrix throughsolid-state polymerization, and there was a strong interaction between PEDOT andnano-ZnO. The FTIR, UV-vis, and XRD results showed that the composites weresuccessfully synthesized, and there was a strong interaction between PEDOT andnano-ZnO. The TEM results suggested that the composites were a mixture ofshale-like PEDOT and less aggregated nano-ZnO. The photocatalytic activity resultsindicated that the incorporation of ZnO nanoparticles in composites can enhance thephotocatalytic efficiency of composites under both UV light and natural sunlightirradiation, and the highest photocatalytic efficiency under UV light (98.7%) andnatural sunlight (96.6%) after5h occurred in the PEDOT/15wt%ZnO nanocomposite.(4)poly(3’,4’-ethylenedioxy-2,2’:5’,2"-terthiophene)/ZnO(PTET/ZnO) compo-sites with the ratio of PTET and nano-ZnO from3:1to1:3were synthesized by handgrinding and ball milling methods, respectively. Results showed that the stronginteractions between the PTET and nano-ZnO occurred in the case of ball millingmethod. Results also proved that the crystallinity of ZnO was not disturbed in bothmethods, and the nano-ZnO was uniformly distributed in polymer matrix in the caseof ball milling method. The comparative studies showed that the addition of the nano-ZnO could enhance the photocatalytic activities of the composites. The highestdegradation efficiency(100%) at3h under UV light irradiation occurred in the case ofPTET/ZnO(1:1) synthesized by ball milling method.(5) PTPT/ZnO and PTMPT/ZnO composites prepared by mechanical ball millingmethod with the mass ratio of polymer and nano-ZnO for1:1. FTIR, UV-vis resultsshowed that the peresence of the nano-ZnO can enhance the conjugation degree of thecomposites. And comparative study showed that the there is strong enteractionbetween polymer and nano-ZnO in the case of poly (TMPT)/ZnOcomposite, whichcould enhance the photocatalytic activity of composite. And highest degradationefficiency is (97.2%) by (TMPT)/ZnO photocatalysis.