氧化石墨烯3

pubs.acs.org/Langmuir?2010AmericanChemicalSociety

HairyCarbonNanotube@Nano-PdHeterostructures:Design,Characterization,andApplicationinSuzukiC-CCouplingReaction

SamiaMahoucheChergui,*,?AlexandreLedebt,?FaynaMammeri,?Fr??ed??ericHerbst,?

BenjaminCarbonnier,?HatemBenRomdhane,§MichelDelamar,?andMohamedM.Chehimi*,?

ITODYS,UniversityDenisDiderot&CNRS(UMR7086),15rueJeandeBa?¨f,75013Paris,France,

??riauxdeParisEst,CNRS(UMR7182),2-8rueH.Dunant,94320Thiais,France,InstitutdeChimieetdesMate

??desSciencesdeTunis,andLaboratoiredeChimieStructuraleetOrganique,Faculte

CampusUniversitaire,2092ManarII,Tunisia

ReceivedJuly13,2010.RevisedManuscriptReceivedSeptember6,2010

Poly(glycidylmethacrylate),PGMA,waspreparedviaATRPinbulksolution,anditsepoxygroupswerefurtheracid-hydrolyzedinordertoobtainapolymerwithglycerolmoieties(notedPOH).ThePOHchainendC-BrbondsweresubjectedtoanucleophilicattackbyNaN3,resultinginazide-terminatedPOH(POH-N3).TheCNTsweremodifiedbyin-situ-generatedalkynylateddiazoniumcationsfromthepara-alkynylatedanilineoftheformulasH2N-C6H4-CtC-H,yieldingCNT-C6H4-CtC-Hnanotubes.Theazide-functionalizedpolymerPOH-N3wasclickedtothealkynyl-modifiedCNTsgivingCNT@POHhybrids,whichwerefurthersubjectedtoanoxidationresultingincarboxylatedpolymer-modifiedCNTs(notedCNT@PCOOH).Theas-designedhairyCNTsservedasefficientplatformsforthein-situsynthesisandmassiveloadingof3nmsizedpalladiumnanoparticles(NPs).TheCNT@PCOOH@PdheterostructurespreparedsofarexhibitedanefficientcatalyticeffectintheC-CSuzukicouplingreactionandwereregenerateduptofourtimeswithoutanysignificantlossofcatalyticactivity.

Introduction

Carbonnanotube-supportednanoparticlesheterostructuresarenanometerscaleandhighsurfaceareaobjectsthatarethesubjectofnumerousacademicandappliedtechnologicalstudies1withinthedomainsofcatalysis,2energyconversion/fuelstorage,3electronicnanodevices,4andsensors.5

Inthecatalysisdomain,carbonnanotubes(CNTs)havebeenusedasanalternativesupportsduetotheiruniquetubularstructure,highsurfacearea,highthermalandelectricalconductivity,andhighcorrosionresistance.Forelectronicsdevices,CNT-supportedcata-lystswereemployedtodesigncatalystsarrays.4Asfarassensordevicesareconcerned,itwasshownthatCNTshavegreatpotentialinrecognizingmolecularspecies,withaverygooddetectionlimit,providedthattheyaredecoratedbypolymersorbymetallicnanoparticles(NPs).6

Fromthesefewexamples,itisclearthatanefficientsupport(e.g.,CNTs)restsonitsabilitytostronglybindanddispersemetallicnanoparticles.Thiscanbeachievedbye.g.laser-assistedphysicaltreatmentofCNTs7whichleadstoaneffectiveimmobilizationofPdnanoparticlesleadingtostableCNT/Pdheterostructures.Intheabsenceofsuchatreatment,nodecorationoftheMWCNTswasobservedbysimplemixingwithnanoparticlesuspensions.AdrymethodemployingplasmasurfacetreatmentofCNTs

*Correspondingauthors:e-mailmahouche.samia@gmail.com,Pht33157278854(S.M.C.);e-mailchehimi@univ-paris-diderot.fr,Pht33157276863(M.M.C.).(1)Wildgoose,G.G.;Banks,C.E.;Compton,R.G.Small2006,2,182.

(2)Yang,S.D.;Zhang,X.G.;Mi,H.Y.;Ye,X.G.J.PowerSources2008,175,26.

(3)Georgakilas,V.;Gournis,D.;Tzitzios,V.;Pasquato,L.;Guldi,D.M.;Prato,M.J.Mater.Chem.2007,17,2679.

(4)Mubeen,S.;Zhang,T.;Yoo,B.;Deshusses,M.A.;Myung,N.V.J.Phys.Chem.C2007,111,6321.

(5)Wang,Y.;Yeow,J.T.W.J.Sens.2009,ArticleID493904,doi:10.1155/2009/493904.

(6)Gao,G.;He,H.;Zhou,L.;Zheng,X.;Zhang,Y.Chem.Mater.2009,21,360.(7)Henley,S.J.;Watts,P.C.P.;Mureau,N.;Silva,S.R.P.Appl.Phys.A:Mater.Sci.Process.2008,93,875.

inducedauniformdispersionofPdclustersatthecarbonnanosupportincomparisontothepristinenanotubes.8SurfacechemicalmodificationcanbeachievedatthesynthesisstageoftheCNTs(in-situmodification)9orbypost-functionalizationemployingmolecularmodifierssuchasaminophenylgroups.10

InordertocontroltheCNT/NPinterfaceandtofavorahighNPloading,coordinatingpolymergraftscanactasmacromolec-ularcouplingagentsastheycarrymultiplebindingsites.Inthisregard,polypyrrole(PPy)hasbeenusedasanultrathinlayeronCNTstobindmetallicnanoparticlesforelectrocatalysisapplications.11

Asanalternativetoconductivepolypyrroleorpoly(ethyleneimine),theteamledbyChaoGaograftedpoly(meth)acrylatestooxidizedCNTsviasurface-initiatedATRP.Theydemonstratedthathairynanomaterialscouldserveassupportforthein-situnucleationofAg,Pt,andAunanoparticles.12,13TheyhavealsograftedCNTswithpolymersbearingalkynyl(azide)fortheimmobilizationofmagneticparticlesmodifiedbyazide(alkynyl)groups.14

Alternatively,itispossibletoachievecovalentbondingofpolymerstoCNTs,inmildconditions,throughgraftedaryllayersderivedfromeitherisolated15,16orin-situ-generated17-19

(8)Felten,A.;Ghijsen,J.;Pireaux,J.-J.;Drube,W.;Johnson,R.L.;Liang,D.;Hecq,M.;vanTendeloo,G.;Bittencourt,C.Micron2009,40,74.

(9)Jiang,H.;Zhuc,L.;Moon,K.-S.;Wong,C.P.Carbon2007,45,655.(10)Guo,D.J.;Li,H.L.Carbon2005,43,1259.

(11)Selvaraj,V.;Alagar,M.Electrochem.Commun.2007,9,1145.

(12)Gao,C.;Vo,C.D.;Jin,Y.Z.;Li,W.;Armes,S.P.Macromolecules2005,38,8634.

(13)Gao,C.;Li,W.;Jin,Y.Z.;Kong,H.Nanotechnology2006,17,2882.(14)He,H.;Zhang,Y.;Gao,C.;WuJ.Chem.Soc.,Chem.Commun.2009,1655.(15)Price,B.K.;Hudson,J.L.;Tour,J.M.J.Am.Chem.Soc.2005,127,14867.(16)Dyke,C.A.;Tour,J.M.NanoLett.2003,3,1215.(17)Bahr,J.L.;Tour,J.M.Chem.Mater.2001,13,3823.

(18)Hudson,J.L.;Casavant,M.J.;Tour,J.M.J.Am.Chem.Soc.2004,126,11158.

(19)Lawson,G.;Gonzaga,F.;Huang,J.;DeSilveira,G.;Brooka,M.A.;Adronov,A.J.Mater.Chem.2008,18,1694.

Langmuir2010,26(20),16115–16121PublishedonWeb