Preparation And Studies Of Polyaniline/Polypyrrole-Keggin Polyoxometalate Microtubes

Polyoxometalates have attracted extensive attention because of their abundant electrochemical properties,relatively strong catalytic activities,adjustable structure and construction.Among the conjugated polymers,Polyaniline(PANI)and Polypyrrole(PPY)are typical conductive macromolecule,they have been research hotpot in recent years because of their stabilities,special doping mechenism,unique electrochemical and optical properties.this paper combine the excellent properties of POM with PANI/PPY and the feature of hollow structure of microtubes,new organic-inorganic microtube materials based on POM were successfully designed and synthesized(PANI@POM and PPY@POM),conductivity and application of the composite microtubes in electrocatalytic oxidation methanol were studied.Fe3+,Cu2+ cation-tuned Keggin-type POM microtubes(Fe3+-SiW12,Cu2+-SiW12)Mo/V-substituted Keggin-type POM microtubes(SiW11Mo,SiW11V)have been synthesized through a simple free-template aqueous synthesis method.Next,organic-inorganic microtubes of PANI@Fe3+-SiW12,PANI@Cu2+-SiW12,PANI-SiW11 Mo and PANI-SiW11 V composite microtubes were synthesized by chemical oxidative polymerization and characterized by optical microscope,ESEM,EDS,FT-IR,UV-Vis/DRS,XRD,TG etc.conductivity and electrocatalytic oxidation for methanol of the composite microtubes were studied.The conductivity of PANI@Fe3+-SiW12 is about four times than SiW12 microtubes without modification and is about one time than Fe3+-SiW12 microtubes were demonstrated by experimental results.And PANI-SiW11 V microtubes also have favourable conductivity.When Pt/C catalysts immobilize with the composite microtubes,its electrocatalytic activity for methanol also get improvement.On accout that preparation of polypyrrole by chemical oxidative polymerization can achieve organic coupling to get the conjugated molecule of long chains,and achieve doping process at the same time.So based on the prepared Fe3+-SiW12,Cu2+-SiW12 microtubes,PPY@Fe3+-Si W12,PPY@Cu2+-SiW12 microtubes have been prepared by the chemical oxidative polymerization by us.And the microtubes have been characterized by some ways.The electrocatalytic activities of Pt/C catalysts immobilized with the composite microtubes for methanol were studied.