Synthesis Of Copolymers Of Pyrrole-thiophene And Their Applications In Magnetic Separation And Supercapacitors

Conducting polymers?polypyrrole,polythiophene,polyaniline,and copolymer?are a kind of new functional polymer materials.In recent years,conducting polymers have attracted considerable interest due to their wide applications in electrochemistry,adsorption,catalysis,sensors,and electrochromism.In this paper,a modified Fenton reagent was used as an oxidant to prepare copolymer of pyrrole-thiophene?cPPyTh?and multishell-structured magnetic nanocomposite of Fe₃O₄/SiO₂/cPPyTh in aqueous solution by a chemical oxidative polymerization?COP?method.The as-prepared nanocomposite was successfully applied to selective separation of Au?III?in copper concentrate aqueous solution.The results show that:1.cPPyTh can be easily formed upon Fe₃O₄/SiO₂ with modified Fenton reagent withoutusinginorganicmedium,producingFe₃O₄/SiO₂/cPPyThmagnetic nanocomposite with superparamagnetism,N,S-coexisting surface,and tunable N/S ratio.The formation of cPPyTh copolymer is supported by theoretical calculations and reflected by the XPS,FT-IR,and CV techniques.2.Fe₃O₄/SiO₂/cPPyTh nanocomposite exhibits an enhanced acid resistance and an excellent adsorption performance for Au?III?recovery from multiionic aqueous solution.At room temperature,the adsorption capacity of Fe₃O₄/SiO₂/cPPyTh toward Au?III?can dramatically increase to 559.7 mg g^-1 within 5min,and finally reach an equilibrium adsorption capacity of 845.9 mg g^-1.3.Fe₃O₄/SiO₂/cPPyTh exhibits highly selective adsorption toward Au?III?versus interfering ions?Mg?II?,Cu?II?,Zn?II?,As?V?,Cd?II?,and Pb?II??.After consecutive use five times,the adsorption/recovery percentages of Au?III?from multiionic solution with Fe₃O₄/SiO₂/cPPyTh retain 93.3%and 92.3%,respectively,showing a good reusability of the adsorbent.Fe₃O₄/Si O₂/cPPyTh exhibits superior adsorption performance for Au?III?recovery compared with Fe₃O₄/SiO₂/PPy,Fe₃O₄/SiO₂/PTh,and many other adsorbents in recent reports,presenting a promising candidate for Au?III?recovery from gold ion-containing effluents.4.The superior adsorption capacity of Fe₃O₄/SiO₂/cPPyTh is attributed to the lower oxidation potential of Py compared with Th but the higher affinity of S to gold-ion species compared with N,rendering a synergistic effect for Au?III?adsorption.In addition,we have also prepared pyrrole-thiophene copolymer composite conductive paper by using an in situ polymerization method.The pyrrole-thiophene copolymer-based paper electrode was tested as an electrode material in solid-state flexible supercapacitors.The composite conductive paper can lighten LED bulbs.The cPPyTh/paper composite is characterized with FT-IR,SEM,and four-probe conductivity techniques.Electrochemical properties of cPPyTh/paper solid-state flexible supercapacitor were investigated by cyclic voltammetry,galvanostatic charge/discharge,and alternative current impedance spectroscopy.The results show that:1.cPPyTh was successfully grown on the print paper and filter paper.2.The cPPyTh/paper composite can be used as a conducting wire to lighten LED bulbs.3.The cPPyTh/paper composite electrodes can be directly assembled into all-solid-state flexible supercapacitors.When tested the current density of 0.1,0.2,1,and 5 mA cm^-2 through galvanostatic charge/discharge technique,the specific areal capacitance of the sample was 46.63,22.75,20.63,9.13,and 1.90 mF cm^-2,respectively.With increasing the current density,the flexible supercapacitor exhibits a significant capacitance fading.