多孔氮化硼最新研究进展

Porous boron nitride with a high surface area: hydrogen storage and water treatment

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IOPPUBLISHING

Nanotechnology24(2013)155603(7pp)

NANOTECHNOLOGY

doi:10.1088/0957-4484/24/15/155603

Porousboronnitridewithahighsurfacearea:hydrogenstorageandwatertreatment

JieLi1,JingLin1,XuewenXu1,XinghuaZhang1,YanmingXue1,JiaoMi1,ZhaojunMo1,YingFan1,LongHu1,XiaojingYang1,

JunZhang1,FanbinMeng1,SongdongYuan2andChengchunTang1

1

SchoolofMaterialScienceandEngineering,HebeiUniversityofTechnology,Tianjin300130,People’sRepublicofChina2

SchoolofChemistryandChemicalEngineering,HubeiUniversityofTechnology,Wuhan430068,People’sRepublicofChina

E-mail:dr.linjing@gmail.com,yuansd2001@163.comandtangcc@hebut.edu.cn

Received16January2013,infinalform28February2013Published22March2013

Onlineatstacks.iop.org/Nano/24/155603

Abstract

Wereportonthesynthesisofhigh-qualitymicroporous/mesoporousBNmaterialviaafaciletwo-stepapproach.Anextremelyhighsurfaceareaof1687m2g−1andalargeporevolumeof0.99cm3g−1havebeenobservedinthesynthesizedBNporouswhiskers.TheformationoftheporousstructurewasattributedtothegroupeliminationoforganicspeciesinaBNprecursor,melaminediboratemolecularcrystal.Thiseliminationmethodmaintainedtheorderedporestructureandnumerousstructuraldefects.Thefeaturesincludinghighsurfacearea,porevolumeandstructuraldefectsmaketheBNwhiskershighlysuitableforhydrogenstorageandwastewatertreatmentapplications.WedemonstrateexcellenthydrogenuptakecapacityoftheBNwhiskerswithhighweightadsorptionupto5.6%atroomtemperatureandattherelativelylowpressureof3MPa.Furthermore,theBNwhiskersalsoexhibitexcellentadsorptioncapacityofmethylorangeandcopperions,withthemaximumremovalcapacityof298.3and373mgg−1at298K,respectively.

(Somefiguresmayappearincolouronlyintheonlinejournal)

1.Introduction

Porousmaterialsmadeofinorganicoxideshaveattractedgreatattentionbecauseoftheirpotentialforapplicationsinairandwaterpurification,catalysis,optics,gasseparation,electronics,ecologyetc[1–10].Sincethesuccessfuldiscoveryoforderedmesoporousmaterialsin1992[11,12],theinterestinexploringnewporousmaterialshasgrownsignificantly.Hexagonalboronnitride(h-BN),ananalogueofgraphite,isandielectricmaterialwithawidebandgapof5–6eV[13,14],andwhencrystallizedinporousstructuredisplaysuniquephysicalandchemicalproperties,includinghighspecificsurfacearea,lowdensity,superbcorrosionresistance,highthermalconductivity,chemicaldurabilityandoxidationresistance[15,16].ThesefeaturesmakeporousBNa

0957-4484/13/155603+07$33.00

1

promisingcandidateforapplicationsinvariousfields,suchashydrogenstorage,organicandinorganicpollutantadsorptionandcatalysisinveryharshenvironments[17–22].However,itiswellknownthathydrogenstorageandremovaloforganicandinorganicpollutantsinasafeandeffectivefashionstillremainatechnicalchallenge.RecentevidencehasrevealedthefeasibilityofBNnanomaterialsaspotentialhydrogenstoragemediaandsorbentsfortheadsorptionoforganicandinorganicpollutants.Effectiveuptakehasbeendetectedinnanotube,nanobambooandothernanostructuredBN[23–25].Surface,defects,dopingorpossibleholecharacteristicsinthesestructuresmightplayacrucialroleinhydrogenstorageandpollutantadsorptionofBN-basedmaterials.

VarioussyntheticeffortshavealreadybeenundertakenforporousBN.Atypicalmethodincludesreplicafabrication

c2013IOPPublishingLtdPrintedintheUK&theUSA󰀃

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usingtemplates[15,26–28]andelementalsubstitution[29,30].Evenso,itisstillanimportanttasktofindacost-efficientmethodfortheproductionofhigh-qualityporousBN,especiallyfocusingonuniformityoftheholediameter,purity,expandedsurfaceareaandhighyield.

Hereinwereportafacileapproachforthesynthesisofahigh-qualitymicroporous/mesoporousBNmaterial(namedHBBN-1).Readilyavailableandinexpensiverawmaterials,boricacidH3BO3andmelamineC3N6H6,werethestartingreactants.Theiraqueousreactionat85–90◦Cformsamolecularcrystal,melaminediborate,andsuitablehigh-temperaturepost-treatmentat1460◦CinN2flowformelaminediboratecanformapurehexagonalBNwithporousstructures,tofinallyobtainHBBN-1.TheHBBN-1exhibitsanexceptionallyhighsurfaceareaof1687m2g−1andalargeporevolumeof0.99cm3g−1.Tothebestofourknowledge,thespecificsurfaceareaandporevolumearemuchhigherthanthoseofporousBNreportedinotherliterature[20,26–31].Furthermore,thehydrogenadsorptioncapacityofthenovelporousmaterialisupto5.6wt%at3MPa,anditsmaximumremovalcapacityofmethylorange(MO)andcopperionsismeasuredtobe298.3and373mgg−1at298K,respectively.Therefore,webelievethattheHBBN-1materialisapossiblecandidateforhydrogenstorageandwastewatertreatment,openingadoorforincreasinghydrogenstorageweightdensityandimprovingthewastewatertreatmentcapacityintheBNsystem,bydetailedconsiderationsoftheBNporousstructure.

2.Experimentalsection

2.1.Synthesis

Inatypicalsynthesis,3.71gofH3BO3and3.78gofC3N6H6weredissolvedin250gofdistilledwater.Thereactionmixtureswereheatedat85◦Cfor12h,andthennaturallycooled(∼6h)toroomtemperaturetogiveawhiteprecipitate.Thewhiteprecipitatecontainingrod-shapedcrystalssuitableforsinglecrystalx-raydiffractionwasfilteredandwashedwithde-ionizedwater.Thesamplesweredriedat90◦Cfor12htoobtainmelaminediboratemolecularcrystals.Subsequently,thecrystalsweretreatedthroughamulti-stageheatprocesstoproduceHBBN-1inanaluminatube:thesampleswerefirstpre-treatedat300◦Cfor1handthenthetemperaturewasslowlyincreased(2◦Cmin−1)to1100◦Candkeptthereforanother2h;finally,theywereheatedto1460◦Catarateof5◦Cmin−1andkepttherefor4h.AllreactionswerecarriedoutinaflowofN2(0.5lmin−1).Toremovethepossiblecarbonremnant,atreatmentprocessat550◦Covernightinairwasalsoadopted.2.2.Characterizationandapplication

Thestructureandmorphologyofthesampleswereexaminedusingx-raypowderdiffraction(XRD,BrukerD8FOCUS),fieldemissionscanningelectronmicroscopy(SEM,HitachiS-4800),Fouriertransforminfrared(FTIR)spectrarecordedonaNicolet7100spectrophotometerbetween400and

2

4000cm−1,and200kVhigh-resolutiontransmissionelectronmicroscopy(HRTEM,TecnaiF20,Philips,Netherlands)withanenergy-dispersivex-rayanalyzer(EDX)andanelectronenergylossspectrometer(EELS).Thenitrogenphysisorptionisothermsweremeasuredat77KonanAutoSorbiQ-CTCDanalyzer.Priortothemeasurement,thesampleswereactivatedinvacuumat300◦Cfor8h.TheBrunauer–Emmett–Teller(BET)specificsurfaceareawascalculatedfromthenitrogenadsorptiondatainrelativepressurerangingfrom0.01to0.3.Duetothebroadporesizedistribution(PSD),rangingfrommicroporestomesopores,thenon-localdensityfunctionaltheory(NLDFT)methodwasusedtocalculatetheporewidthsandporesizedistributions(ASiQwinsoftware).Indetail,asetofisothermscalculatedforasetofporesizesinagivenrangeforagivenadsorbateconstitutesthemodeldatabase.Suchasetofisotherms,calledakernel,isthebasisfortheporesizeanalysisbydensityfunctionaltheory(DFT).ThecalculationofthePSDisbasedonasolutionofthegeneralizedadsorptionisotherm(GAI)equation,whichcorrelatesthekerneloftheoreticaladsorption/desorptionisothermswiththeexperimentalsorptionisotherm.TheamountofhydrogenadsorptionwasexaminedbyagravimetricmethodwithaPCD-2008(Shanghai)hydrogenatoratroomtemperature(298K)andatthepressurerangingfrom0.1to3MPa.AdoublebeamUV/Visspectrophotometer(Hitachi,U-3900H)wasusedtodeterminetheconcentrationofdyesamples.Concentrationsofmetalionsweremeasuredbyhighdispersioninductivelycoupledplasmaemissionspectroscopy(ICP)(Teledyne-LeemanLabs,USA).

3.Resultsanddiscussion

FromtheSEMobservation,aribbon-likemorphologycanbeverifiedastherepresentativeappearanceoftheHBBN-1(calcinedatanoptimizedtemperatureof1460◦Cfor4h),asshowninfigure1(a).Thewhiskershaveaveragediametersof0.5–3.0µmandlengthsof50–100µm.Figure1(b)isatypicalTEMimageofanindividualwhiskerwithauniformwidthof500nm.Itclearlyrevealsthepresenceofcrippledsurfaceswithporesandprotrudingedges.Theelectronenergylossspectroscopy(EELS)analysesforasinglewhiskerisshowninfigure1(c),clearlyshowingthepresenceoftheK-shellexcitationshellsofB(188eV,BKedge)andN(401eV,NKedge).Thesharpπ∗andσ∗peaksoftheBandNKedgesaretypicalforthesp2bondingconfiguration[32],whicharecharacteristicsofBandNatomsofthelayers.

DetailedTEMobservationsrevealtheporousnatureofthewhisker,asshowninfigure2(a).Thewhiskerdisplaysopenedgesandtheinnerinterlinkedlayersthatformcavities(pores).Occasionally,wealsoobservedahigh-degreeorderedHBBN-1fragmentwithasmallthickness,whichisshowninfigure2(b).Itisworthnotingherethatthefragmentshowsaregularhexahedronappearance,whichistypicalforgraphite-likeporousmaterials.However,morefrequentlyobservedmorphologypresentsthestackedandopenedgesconsistingofinterlinkedlayers,asrevealedbyHRTEMstudies.TheBNlayersarewellcrystallizedwithaninterlayer

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Figure1.TypicalporousboronnitridematerialsHBBN-1synthesizedinoptimalsyntheticconditions:(a)SEMimage,(b)TEMimageofasinglewhiskerand(c)EELStakenfromthesurfaceofthewhiskershownin(b).Tracesofoxygencanbealsodetectedforthefinalproduct.

Figure2.(a,b)TypicalTEMimagesoftheHBBN-1and(c)thecorrespondingHRTEMimage(layerdistanceofabout0.34nm,insetshowingtheselectedareaelectrondiffractionpattern).

distanceof∼0.34nm,characteristicofad0002spacinginahexagonalBN[15,33].Thecorrespondingselectedareaelectrondiffraction(SAED)pattern(figure2(c),inset)revealsthedisorderedlayerarrangementofBNwhiskers.AfurtherinspectionoftheoutersurfaceofthewhiskersshowsthepresenceofexposedBNedgesarisingfromunfoldedribbons.ItisbelievedthatthebareBNedgewillprovideahighreactivityoftheBNwhiskers,whichissuitableforthedevelopmentofthehydrogenadsorption[20].

Figure3illustratesanitrogenadsorption/desorptionisothermandthecorrespondingPSDofHBBN-1whiskers.Themeasuredisotherm(figure3(a))canbeclassifiedasatype-IVisothermaccordingtotheIUPACnomenclature,andexhibitsanH4typebroadhysteresisloop[34].Itisknownthat

3

therelativepressure(p/p0)positionoftheinflectionpointiscorrelatedtothediametersofthemicroporeandmesopore.Withtheincreaseoftherelativepressure(p/p0>0.42),theisothermdisplaysasharpstepcharacteristicofcapillarycondensationofnitrogen.Thehysteresisbetweenrelativepressure(p/p0)of0.42and1.0revealsthecharacteristicofbothmicroporesandmesopores.TypeH4loopsalsoindicatethattheporescontainnarrowslit-shapedpores,soweuseanon-localdensityfunctionaltheory(NLDFT)methodtodeterminetheporewidthsandPSDforHBBN-1[35].ByusingtheNLDFTmethod,thePSDwascalculatedandshowninfigure3(b).ItindicatesthatHBBN-1whiskersshowabroadPSD,whichgivesabimodaldistributionwiththemaincharacteristicporesizesof∼1.3and∼3.9nm.Meanwhile,averyhighsurfaceareaof1687m2g−1andahighporevolumeof0.99cm3g−1(includingthevolumeofmicroporesas0.45cm3g−1andmesoporesas0.54cm3g−1)couldbedetermined.

ItisnoteworthythattheHBBN-1whiskersexhibitanexceptionallyhighsurfaceareaof1687m2g−1.ThisvalueisremarkablyhigherthanthoseofanyreportedBNmaterials,suchashollowsphericalBNparticles(1400m2g−1)[31],collapsedBNnanotubes(7m2g−1)[20],micro-,mesoporousBNpreparedusingzeolitesasatemplate(570m2g−1)[28]andmesoporousBNsynthesizedviaanelementalsubstitutionmethod(565m2g−1)[29].

ThecharacterizationofporestructureoftheHBBN-1canbefurthercheckedbylow-angleXRDanalyses,asdepictedinfigure4.Abroadpeakaround7.4◦(2θ)isobserved,correspondingtoanapproximate1.3nmlayerdistance,indicatingalong-rangeorderingperiodicityof1.3nm[28].Thisimpliesalong-rangeorderedarrangementofmicroporeinHBBN-1,inagreementwiththeobservationofthenitrogenadsorption/desorptionmeasurement.Anotherlow-angleXRDpeak(at∼1.8◦)oflong-rangeorderedmesopores(∼3.9nm)wasnotobviouslydetected,possiblyduetothelackoflong-rangeordering.Webelievethat,inspiteofthelackofstrongevidence,theformationofthepore1.3nminsizeisrelatedtothereconstructionofthe(003)interlayer,andthe3.9nmporecorrespondstothe(100)planeofhexagonalBN[36].

Heattreatmentalsoaffectssurfaceareasandporevolumes.Thetexturalpropertiesofthewhiskerscalcinedat

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Figure3.CharacterizationofporestructureoftheHBBN-1.(a)Nitrogenadsorption/desorptionisotherm,(b)thecorrespondingporesizedistributionsobtainedbytheDFTmethod(fullline)andthecumulativeporesizedistribution(squaresymbol).

Figure4.Low-angleXRDpatternofHBBN-1(insetshowingtypicalhigh-angleXRDpattern).

Table1.TexturalparametersoftheBNwhiskerscalcinedatdifferenttemperaturesrangingfrom1260to1560◦C.

Temperature(◦C)1560146013601260VP(m2g−1)10451687673158Adsorption(cm3g−1)0.570.990.430.18dp,DFT(nm)1.2,3.91.3,3.91.3,3.91.4,3.7toBNcrystals,basedonthefollowingexperimentalobservations.First,themainprecursor,C3N6H6·2H3BO3,hasbeenconfirmedtobeahydrogen-bondedstructure[37],formingalayer-likemorphologybytheinterlinkedplanartriangularH3BO3andC3N6H6molecules[38].Second,FTIRanalyses(figure5(b))revealthattheprecursorandtheproductsheattreatedatdifferenttemperaturesinvolvevariousorganicgroups,includingB–NH2/B–OH(∼2900,∼3430and∼3600cm−1),C–O(∼1630cm−1),B–N(∼1400cm−1),B–N–O(∼1160cm−1),C–N(∼1120cm−1),C–O(∼1080cm−1),B–N–O(∼930cm−1),B–N–B(∼800cm−1)andO–B–O(∼490cm−1)[39,40].Withincreaseofheatingtemperature(upto1100◦C),mostoftheorganicgroups,suchasC–O,C–NandB–N–O,wereeliminated;onlythepeakscorrespondingtothebondsofB–NH2/B–OH,O–B–O,B–NandB–N–Bwereobserved.Thisindicatesthattheeliminationofthesubstitutedgroups(suchasH2O,NH3,N2andCO)andtheformationofB–Nbondsdirectlyresultfromthereactiontemperature[41].Therefore,theformationreactionofBNisexpressedasfollows:

2H3BO3+C3N6H6→C3N6H6·2H3BO3

→2BN+3H2O+2CO+3NH3+N2.

(1)

differenttemperaturesareprovidedintable1.ThedataclearlyindicatethatthesurfaceareaoftheBNwhiskerremarkablyincreasesfrom158to1687m2g−1whenelevatingthetemperaturefrom1260to1460◦C.Accordingly,theporevolumesalsoincreasefrom0.18to0.99cm3g−1.However,withthefurtherincreaseofthetemperatureto1560◦C,thesurfaceareaandporevolumequicklydecrease.Thiscanbemainlyattributedtothermalshrinkageandcollapseoftheporousstructureexperiencedduringthepyrolyticreactionathighertemperatures.

Fortheporeformationmechanism,amodelisnowproposedforthestructuretransformationfromtheprecursor

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DuringtheHBBN-1formationprocess,BNlayers,whichconsistofhexagonalplaneunitsofboronandnitrogenatomslinkedbysp2hybridizedorbitals,areformedandthenpileduplayerbylayercontrolledbyavanderWaalsforce[36,42];meanwhile,theorganicgroupssuchasH2O,NH3,N2andCOareremovedthroughthespacesbetweenlayersorotherpositionslocatedbythesegroups,andleaveporespermanently.Theinterlayereliminationsresultinanorderlyarrangementofthefinalporeswiththesizeof1.3nm;however,theeliminationsfromotherpositionsformaporestructure3.9nminsize.Forthelatter,thespaceremnantshowsslightlyalackoflong-rangeordering.Thisformationmechanismcanalsoexplaintheexperimentalobservationthat

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Figure5.(a)MorphologyoftheHBBN-1precursor.(b)FTIRspectraoftheHBBN-1precursorandthecalcinedproductsatdifferenttemperaturesrangingfrom1260to1560◦C.

thesurfaceareaandporevolumedependstronglyonthepyrolysistemperature.

Thehighspecificsurfacearea,largeporevolumeandrichstructuraldefectsmakeHBBN-1highlysuitableforhydrogenstorageapplications.Thehydrogenuptakebehaviorofthewhiskersatambienttemperature(298K)isshowninfigure6.Theisothermexhibitsthemonotonicincreaseofhydrogenadsorptionwiththeappliedpressure.Thehydrogenadsorptioncapacityisonly∼0.2wt%at0.1MPa,butstrikinglyincreasesto∼5.6wt%at3MPa.Thisvalueissuperiortothehighestvalueof4.2wt%reportedbyTangetalincollapsedBNnanotubes[20].Thisindicatesthat,intheHBBN-1whiskers,theactiveadsorptionsitesforhydrogenmoleculesaremuchmorenumerousthanthoseinotherBNnanomaterials.Moreimportantly,wefoundthatnearly83.9%oftheadsorbedhydrogencanbereleasedwhenloweringthehydrogenpartialpressuretonearlyatmosphericconditions.Furthermore,theadsorptioncurvespresentedinfigure6donotshowremarkablesaturationtendency,andthushigherhydrogenuptakecapacitycanbeexpectedathigherpressure.

ThehydrogenadsorptioninBNmaterialsmayoriginatefromeitherphysisorptionorchemisorption[43].Howeveritisdifficulttoobtainhighhydrogenadsorptioncapacitybyphysisorptionalone[21,43].WebelievethattheobservedhighhydrogenadsorptioncapacityofHBBN-1mainlyresultsfromthefollowingfouraspects.Thelargeporevolumeofmicropores(0.45cm3g−1)facilitatesthephysicaladsorptionofhydrogen[44];thehighspecificsurfaceareaof1687m2g−1playsasignificantroleinthehighhydrogenstoragecapacityduetomoreactiveadsorptionsites[45,46];thepolarB–NbondinporousBNissuitableforthehydrogenchemisorption,becausetheBNwhiskersexhibit‘lop-sided’densitiescharacteristicofaconsiderabledegreeofionicB–Nbonding,andhydrogencantransfermoreelectrondensitytotheelectron-deficientboron[43,47,48];andtheenhancementofhydrogenstorageisadirectconsequenceofmanymoreactivesitesfortheadsorptionofhydrogenduetothehighdensityofstructuraldefectsofferingstrongbindingsitesandenhancingthedissociationofH2onBNwhiskers[43,48–50].

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Figure6.Gravimetricadsorption/desorptioncapacityatroomtemperatureasafunctionofthehydrogenpressureforHBBN-1calcinedat1460◦C.

Suchribbon-likeHBBN-1isalsoexpectedtohaveexcellentperformanceinwatertreatment.MO,asamodeldyecontainingaromaticrings,canbeadsorbedontotheHBBN-1byelectrostaticattractionandcomplexinteractions[21,51].Figure7(a)showstheUV–VisabsorptionspectraoftheMOsolutiontreatedwithHBBN-1atdifferenttimeintervals.ThemaincharacteristicabsorptionpeakofMOisaround4nm.Theinsetoffigure7(a)showscorrespondingphotographicimagesofMOsolutiontakenatdifferenttimesafteraddingtheHBBN-1material.Asshowninfigure7(b),when100mgHBBN-1wasintroducedinto250mlMOsolutionwiththeinitialconcentrationof40mgl−1,∼88wt%ofMOwaseffectivelyremovedfromthesolutionwithin5min,andfinally∼99wt%ofMOwasadsorbedwithin2hatroomtemperature.

TheLangmuiradsorptionisothermhasbeenwidelyusedforthecharacterizationofadsorptionofpollutantsfromliquidsolutions.Itassumesthattheadsorptionofpollutants

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Figure7.(a)UV–Visabsorptionspectraandphotographicimages(inset)oftheaqueousMOsolution(40mgl−1,250ml)atdifferenttimeintervalsafteradding100mgHBBN-1.(b)Thecorrespondingadsorptionrate.(c)AdsorptionisothermsofMO.

Figure8.Adsorptionrateofcopperion(1.8gl−1,250ml)onHBBN-1(1g).

takesplaceinthespecifichomogeneoussiteswithintheadsorbents.Itwasusedtodescribetherelationshipbetweentheequilibriumsoluteconcentrationanditsequilibriumadsorptioncapacity.TheLangmuirisothermisrepresentedintheform

Qe=QmKCe/(1+KCe)

(2)

(105.3mgg−1forazo-dyeacidredB)[56].Itisalsonoteworthythat,afterthetreatmentprocess,thecollectedHBBN-1canbeeasilyregeneratedbycalciningat350◦Cfor2hinair.

Inaddition,theHBBN-1alsoexhibitsvaluableadsorp-tioncapacityformetalions,asshowninfigure8.Herein,asademonstrationofpotentialapplication,HBBN-1wasusedasthesorbentfortheremovalofcopperionsfromsolutions.Forexample,250mlaqueoussolutionwithcopperionconcentrationof1.8gl−1wasmixedwith1gHBBN-1.TheadsorptioncapacityofHBBN-1forcopperionwasmeasuredtobe99mgg−1within20min,andfinallyreached373mgg−1within48hatroomtemperature.TheexcellentadsorptioncapacityofHBBN-1forMOandcopperionsindicatesthatHBBN-1hasremarkableefficiencyinremovingorganicpollutantsandmetalionsfromwastewater,resultingfromthelargeporevolumeofmicropores(0.45cm3g−1),thehighdensityofstructuraldefectsandthehighspecificsurfaceareaof1687m2g−1.Furtherstudiesarestillunderway.

4.Conclusions

Insummary,wehavesuccessfullysynthesizedmicroporousandmesoporousBNmaterialsviaasimpletwo-stepapproach.ThesynthesizedHBBN-1whiskerspossessanexceptionallyhighsurfaceareaof1687m2g−1andalargeporevolumeof0.99cm3g−1.Thesurfaceareasandporevolumesdependstronglyonthetemperature.ThehydrogenadsorptioncapacityofHBBN-1wasmeasuredtobeupto5.6wt%at3MPa,andthemaximumremovalcapacityofMOandcopperionswasmeasuredtobe298.3and373mgg−1at298K,respectively.ThevaluesofthehydrogenadsorptioncapacityandtheremovalcapacityofMOandcopperionsfurtherprovethepossibilityoffindinghighlyeffectivehydrogenstorageandwastewatertreatmentmaterialsintheBNsystem,bythecontrolofporesize,defectsandsurfacearea,asdoneinthepresentworkforporousBN.

whereQeistheadsorbedamountofdyesattheequilibriumconcentration(mgg−1),Ceistheequilibriumconcentrationinsolution(mgl−1),Qmisthemaximumadsorptioncapacitycorrespondingtocompletemonolayercoveringontheadsorbents(mgg−1)andKistheequilibriumconstantrelatedtothefreeenergyofadsorption(lmg−1).TheexperimentaldatawereconsistentwiththeLangmuirisotherms,andthecorrelationcoefficientwas0.991(figure7(c)).ThemaximumadsorptioncapacityofporousBNforMOwasmeasuredtobe298.3mgg−1.WenotethattheourHBBN-1possessessignificantlyhigheradsorptioncapacityfororganicpollutantsascomparedwithotheradsorbents,suchasporousCeO2(250mgg−1forcongored)[51],carbonnanotubesandactivatedcarbon(100mgg−1forphenanthrene)[52],NiOnanosheets(36.1mgg−1forcongored)[53],mesoporousaluminophosphate(35.2mgg−1,formethyleneblue)[54],Australiannaturalzeolite(35.7mgg−1forrhodamineB)[55]andamagneticpowderMnO–Fe2O3composite

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Acknowledgments

TheauthorsaregratefultoDrYHuang,DrTZhang,DrYLu,DrDLiuandDrYMaforexperimentalsupport.ThisworkwassupportedbytheNationalNaturalScienceFoundation

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ofChina(10974041,51172060,51202055,21103056),theNationalBasicResearchProgramofChina(973Programs,2011CB612301),theNaturalScienceFoundationofHebeiProvince(grantNoE2012202040),theKeyBasicResearchProgramofHebeiProvinceofChina(No12965135D)andtheInnovationFundforExcellentYouthofHebeiUniversityofTechnology(No2012001).

References

[1]WuCandBeinT1994Science2661013

[2]ZakhidovcAA,BaghmanRH,IqbalZ,CuiC,KhayrullinI,

DantasSO,MartiJandRalchenkoVG1998Science2827

[3]GatesB,YinYDandXiaYN1999Chem.Mater.112827[4]CormaA1997Chem.Rev.972373

[5]SteinA,MeldeBJandSchrodenRC2000Adv.Mater.

121403

[6]LiDandXiaYN2004NanoLett.4933

[7]OkabeA,FukushimaT,ArigaK,NikiMandAidaTJ2004

J.Am.Chem.Soc.1269013[8]TaguchiAandSch¨uthF2005Micropor.Mesopor.Mater.771[9]VinuA,MurugesanVandHartmannM2003Chem.Mater.

151385

[10]ZhiCY,BandoY,TangC,GolbergD,XieRand

SekigushiT2005Appl.Phys.Lett.87063107

[11]YanagisawaT,ShimizuT,KurodaKandKatoC1990Bull.

Chem.Soc.Japan63988

[12]InagakiS,FukushimaYandKurodaK1993J.Chem.Soc.

Chem.Commun.1993680

[13]CorsoM,AuwarterW,MuntwilerM,TamaiA,GreberTand

OsterwalderJ2004Science303217

[14]KhoJG,MoonKT,KimJHandKimDPJ2000J.Am.

Ceram.Soc.832681

[15]PaineRTandNarulaCK1990Chem.Rev.9073

[16]PattanayakJ,KarTandScheinerS2002J.Phys.Chem.A

1062970

[17]MengXL,LunN,QiYX,ZhuHL,HanFD,YinLW,

FanRH,BaiYJandBiJQ2011J.SolidStateChem.184859

[18]Perdigon-MelonJA,AurouxA,GuimonCand

BonnetotBJ2004J.SolidStateChem.177609

[19]BorovinskayaIP,BuninVAandMerzhanovAG1997

MendeleevCommun.747

[20]TangCC,BandoY,DingXX,QiSRandGolbergD2002

J.Am.Chem.Soc.12414550

[21]LianG,ZhangX,ZhangSJ,LiuD,CuiDandWangQ2012

EnergyEnviron.Sci.57072

[22]ZhiCY,BandoY,TeraoTS,TangCandGolbergD2010

PureAppl.Chem.822175

[23]ChenX,GaoXP,ZhangH,ZhouZ,HuWK,PanGL,

ZhuHY,YanTYandSongDY2005J.Phys.Chem.B10911525

[24]MaRZ,BandoY,ZhuHW,SatoT,XuCLand

WuDH2002J.Am.Chem.Soc.1247672

[25]ChengFY,MaH,LiYMandChenJ2007Inorg.Chem.

46788

[26]HanWQ,BrutcheyR,TilleyTDandZettlA2004NanoLett.

4173

[27]DibandjoP,ChassagneuxF,BoisL,SigalaCand

MielePJ2005J.Mater.Chem.151917

[28]SchliengerS,AlauzunJ,MichauxF,VidalL,ParmentierJ,

GervaisC,BabonneauF,BernardS,MielePandParraJB2012Chem.Mater.2488

[29]VinuA,TerronesM,GolbergD,HishitaS,ArigaKand

MoriT2005Chem.Mater.175887

[30]TerronesMetal2008NanoLett.81026

[31]WoodGLandPaineRT2006Chem.Mater.184716

[32]ChenZG,ZouJ,LiuG,LiF,WangY,WangLZ,YuanXL,

SekiguchiT,ChengHMandLuGQ2008ACSNano22183

[33]TangCC,BandoYandGolbergD2002Chem.Commum.

2826

[34]SingKSW,EverettDH,HaulRAW,MoscouL,

PierottiRA,RouquerolJandSiemeeniewskaT1985PureAppl.Chem.57603

[35]EvansRandTarazonaP1984Phys.Rev.Lett.52557[36]SatoT1985Proc.JapanAcad.Ser.B61459[37]SheldrickGM1990ActaCrystallogar.A467

[38]RoyA,ChoudhuryAandRaoCNR2002J.Mol.Struct.

61361

[39]TangCC,BandoY,HuangY,ZhiCYandGolbergD2008

Adv.Funct.Mater.183653

[40]ZhiCY,BandoY,TangC,GolbergD,XieRand

SekigushiT2005Appl.Phys.Lett.86213110

[41]HagioT,KobayashiKandSatoT1994J.Ceram.Soc.Japan

1021051

[42]HiranoS,YogoT,AsadaSandNakaS19J.Am.Ceram.

Soc.7266

[43]ZhouZ,ZhaoJJ,ChenZF,GaoXP,YanTY,WenBand

SchleyerPVR2006J.Phys.Chem.B11013363

[44]ZhouL2005Renew.Sust.EnergyRev.9395

[45]ZhouL,ZhouYPandSunY2004Int.J.Hydrog.Energy

29319

[46]LiYF,ZhouZ,ShenPW,ZhangSBandChenZF2009

Nanotechnology20215701

[47]LimSH,LuoJZ,JiWandLinJY2007Catal.Today

120346

[48]TeraoT,BandoY,MitomeM,KurashimaK,ZhiCY,

TangCCandGolbergD2008Phys.E402551

[49]OzdoganKandBerberS2009Int.J.Hydrog.Energy345213[50]ReddyALM,TanurAEandWalkerGC2010Int.J.Hydrog.

Energy354138

[51]LuXH,ZhengDZ,GanJY,LiuZQ,LiangCL,LiuPand

TongYX2010J.Mater.Chem.207118

[52]BrooksAJ,LimHNandKilduffJE2012Nanotechnology

23294008

[53]SongZ,ChenLF,HuJCandRichardsR2009

Nanotechnology20275707

[54]KannanC,MuthurajaKandDeviMR2013J.Hazard.Mater.

244–25510

[55]WangSBandZhuZH2006J.Hazard.Mater.B136946[56]WuRC,QuJHandChenYS2005WaterRes.39630

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