Synergistic-and-competitive-adsorption-of-organic-dyes-on-multiwalled-carbon-nanotubes

SynergisticandcompetitiveadsorptionoforganicdyesonmultiwalledcarbonnanotubesShaobinWanga,⇑,ChoonWeiNga,WentaiWangb,QinLib,ZhengpingHaocaDepartmentofChemicalEngineering,CurtinUniversity,GPOBoxU1987,Perth,WA6845,AustraliabEnvironmentalEngineering&QueenslandMicro-andNanotechnologyCentre,GriffithUniversity,NathanCampus,Queensland4111,AustraliacResearchCentreforEco-EnvironmentalSciences,ChineseAcademyofScience,POBox2871,Beijing100085,PRChinahighlightsAdsorptionofmethyleneblueandacidred183onaMWCNTinsingleandbinarydyesystemswasinvestigated.MWCNTshowshigheradsorptioncapacitytomethyleneblueinbothsystems.Asynergisticeffectforbasicandaciddyesoccursinabinarydyesystem.p–pStackingandelectrostaticattractionareresponsiblefordyeadsorption.articleinfoArticlehistory:Received3April2012Receivedinrevisedform1May2012Accepted1May2012Availableonline11May2012Keywords:DyeadsorptionMulti-wallcarbonnanotubeMethyleneblueAcidred183abstractAmultiwalledcarbonnanotube(MWCNT)wasusedasanadsorbentforremovalofacationicdye(methyleneblue,MB)andaciddye(acidred183,AR183)fromaqueoussolutioninsingleandbinarydyesystems.CharacterizationoftheMWCNTandMWCNT-dyesystemswereperformedusingseveraltechniquessuchasFouriertransforminfraredspectroscopy(FTIR),thermogravimetric–differentialther-malanalysis(TG–DTA),zetapotentialandelementalanalysis.AdsorptiontestsshowedthattheMWCNTpresentedhigheradsorptionofMBthanAR183insingleandbinarydyesystems,revealingthatp–pstack-ingisthemaindrivingforceresponsibleforthedye–MWCNTinteraction.Insingledyesystems,theMWCNTpresentedthemaximumadsorptioncapacitiesofMBandAR183at59.7and45.2mg/g,respec-tively.Inabinarydyesystem,asynergisticeffectduetoelectronicattractionbetweenMBandAR183wasfoundatlowAR183concentration(10mg/L),whichpromotestheadsorptionofbothdyesontheMWCNT.However,MBadsorptioncouldbereducedathigherAR183concentration(>20mg/L)duetoastrongelec-trostaticattractionbetweenMWCNT-AR183.�2012ElsevierB.V.Allrightsreserved.1.IntroductionDyesareusuallypresentintheeffluentwaterfrommanyindus-tries