2、angCao,YueGuan,YanfengSun*andGeyuLu*Received16thJanuary2011,Accepted1stMarch2011DOI:10.1039/c1ce05073gPorousSnO2hierarchicalarchitecturesweresynthesizedbycalciningtheprecipitatespreparedthroughafacileone-stephydrothermalsynthesismethod.Fieldemissionscanningelectronmicro
3、scopicandtransmissionelectronmicroscopicresultsrevealedthatthesehierarchicalnanostructureswerebuiltfromtwo-dimensionalporousnanosheets.Themorphologyofthepreparedproductscouldbetailoredbychangingtheprecursorconcentrationandreactiontime.Onthebasisofexperimentalresults,apo
4、ssiblemechanismfortheformationofthethree-dimensionalSnO2hierarchicalnanostructurewasspeculated.Moreover,gassensingtestsshowedthatthesensorusingporousSnO2hierarchicalnanosheetsafterannealingat600Cfor2hexhibitedbettergassensingpropertiescomparedwiththesensorbasedonconven
5、tionallypreparedSnO2nanoparticles.Theenhancementingassensingpropertieswasattributedtotheiruniquestructures.Introduction(Eg?3.6eV,at300K),isanimportantn-typesemiconductorthathasoutstandingpropertiesenablingitsapplicationingasInrecentyears,greatattentionhasbeenfocusedonth
6、esynthesissensing,20photocatalysis,21andphotovoltaics.22Itiswellknownofcomplexmicro/nanoarchitectures,especiallytothree-dimen-thatboththesizeandmorphologyhaveanin?uenceonthesional(3D)hierarchicalarchitecturesthatareassembledusing23–25propertiesofthesemiconductoroxides.T
7、heuniquestruc-1Dand2Dnanoscalebuildingblocks.Todate,awidevarietyofturesmayshownewpropertiesandpromisingapplicationsinfunctionalmaterialswithhierarchicalstructurecanprovidemoremany?elds.Thus,overthepastdecades,severalgroupshaveopportunitiesforexploringnovelpropertiesands
8、uperiordevicesynthesizedSnO2micro-andnanostructureswithdifferentperformances,1–3duetotheirhigherspeci?careaand