The fabrication of silver ion implantation-modified electrode and its

  • 格式:pdf
  • 大小:1.40 MB
  • 文档页数:5

ShortcommunicationThefabricationofsilverionimplantation-modifiedelectrodeanditsapplicationinelectrocatalyticoxidationofformaldehyde

YananYub,MingzheJiab,HuifengTianb,JingboHua,b,*aKeyLaboratoryofBeamTechnologyandMaterialModificationofMinistryofEducation,BeijingNormalUniversity,Beijing100875,PRChina

bCollegeofChemistry,BeijingNormalUniversity,Beijing100875,PRChina

highlightsgraphicalabstract󰀁Anovelprocessforthefabricationofasilver-nanoparticle-modifiedelec-trodeusingionimplantation.󰀁Thezero-valentstateofAgNPsexhibitwellcatalyticperformanceandstabilitytowardstheelectro-oxidationofformaldehyde.󰀁AgNPs/ITOelectrodemaybeapromisinganodeelectrodematerialforthedirectformaldehydefuelcells(DFFCs).

articleinfoArticlehistory:Received21January2014Receivedinrevisedform10May2014Accepted10May2014Availableonline20May2014Keywords:IonimplantationSilvernanoparticlesElectrocatalystFormaldehydeabstractInthiswork,wepresentanovelprocessforthefabricationofasilver-nanoparticle-modifiedelectrodeusingsilverionimplantation.Thismethodisfacile,low-costandenvironmentalfriendlywithouttheuseofanylinkingchemicals.Themodifiedelectrodewasverifiedbyscanningelectronmicroscope(SEM),atomicforcemicroscope(AFM),X-rayphotoelectronspectroscopy(XPS),electrochemicalimpedancespectra(EIS)andcyclicvoltammetry(CV).TheAgNPsformedontheelectrodeareinthezero-valentmetallicstatewithasizedistributionintherangeof3e6nm.Themodifiedelectrodeshowspromi-nentelectrocatalyticactivitytowardstheoxidationofformaldehydewithlong-termstabilityandcouldbeusefulinfuelcells.©2014ElsevierB.V.Allrightsreserved.

1.IntroductionTheelectrochemicaloxidationofsmallorganicmoleculessuchasmethanol,ethanol,formicacidandformaldehydehavebeeninvestigatedintensivelyforthedevelopmentofdirectfuelcellsduetotherelativeeaseofstorageandhandlingaswellashighenergydensity[1e6].Severalreportshavebeenpublishedontheelec-trochemicaloxidationofmethanolandmanyofthemwerecarried

outonnoblemetalelectrodes[7e11].Inrecentyears,therehasbeenincreasinginterestintheelectrochemicaloxidationofform-aldehyde[12e15].NoblemetalssuchasPtandPdareinitiallygoodcatalystsfortheelectro-oxidationofsmallorganicmolecules.NumerousreportshavebeenpublishedontheoxidationofformaldehydeandmostofthemarecarriedoutonPtorPdcatalyst[6,16,17].However,thehighcostofnoblemetalsinhibitstheirapplicationinfuelcells.Therefore,theefforttofindingoutanabundant,inexpensiveandefficientelectrocatalyticmaterialasthesubstitutefornoblemetalcatalystsisofgreatsignificance.AgismuchcheaperthanPtandPd.Ithasthehighestelectricalconductivityamongthemetalsandsilvernanoparticles(AgNPs)havebeenexploredtraditionallytobe

*Correspondingauthor.CollegeofChemistry,BeijingNormalUniversity,Beijing

100875,PRChina.E-mailaddress:hujingbo@bnu.edu.cn(J.Hu).

ContentslistsavailableatScienceDirectJournalofPowerSources

journalhomepage:www.elsevier.com/locate/jpowsour

http://dx.doi.org/10.1016/j.jpowsour.2014.05.0350378-7753/©2014ElsevierB.V.Allrightsreserved.

JournalofPowerSources267(2014)123e127employedascatalystsinvariousreactions[18e20].Inrecentyears,therearemyriadsofmethodstoprepareAgNPs,suchaschemicalreduction[21],electrochemicaldeposition[22],dropcasting[23]andmetal-vaporsynthesis[24].Nevertheless,itisstillexpectedthatthelessuseofstabilizersandbindingreagentswouldimprovetheperformanceofthemodifiedelectrodesignificantlyintheconsiderationofthenegativeeffectsbroughtbythesechemicals.Ionimplantationisakindofmaterialsurfacemodificationtechnique,whichprovidespracticalandexcellentelectrodemate-rialswithlong-termstability.Bythismethod,wecanmodifythemetallicnanoparticlesonthesubstrateandcontroltheirsizejustbytheimplantationcondition.Inaddition,theprocessisfacile,low-costandeco-friendlywithouttheuseofanyotherchemicals[25e30].Inourpreviousreports,wehavepreparedseveralmetal-nanoparticle-modifiedelectrodessuccessfullybyionimplantation[7,31,32].Theseelectrodesexhibitedverylowbackgroundcurrentandexcellentelectrochemicalstability,evenafterultrasonictreatment,indicatingthehighstabilityofthenanoparticlesonthesurface.Indiumtinoxide(ITO)waschosenastheelectrodesub-strateduetoitswideelectrochemicalworkingwindowandstableelectrochemicalproperties[33e36].Inaddition,itcanbeavailableataverylowcostfromindustrialmassproduction.Inthispaper,ourgroupdescribesanewmethodtoprepareAgNPsmodifiedITOelectrode(AgNPs/ITO)bysilverionimplanta-tion.ThepreparedAgNPsontheITOelectrodesurfacearefreefromanychemicalreagentssurroundingorbindingtothem.TheAgNPs/ITOelectrodeswereusedfortheelectrocatalyticoxidationofformaldehydeandexhibitedremarkablecatalyticactivitywithgoodstability.