表面光催化还原铁对TiO2SiO2光催化活性的影响黄琮

133Vol.13No.3TheChineseJournalofNonferrousMetals20036Jun.　2003:10040609(2003)03079304TiO2/SiO2①黄　琮1,王良焱1,徐悦华1,李新军1,郑少健1,李芳柏1,2(1.,510070;2.,,510650)　:TiO2/SiO2,XRD,TEM、。。:,Fe,。n(Fe)∶n(Ti)1.0%,,1.0%。Fe。Fe3+Fe2+,Fe3+,Fe2+,,,。:TiO2/SiO2;;Fe:0643:A　　,TiO2,,,、。,TiO2。,TiO2,、[1]。,TiO2/SiO2[2,3],、TiO2。、。[4]、[5,6],,,,。TiO2/SiO2,。。1　1.1　TiO2/SiO2TiO2SiO2。(,)、、、(,)、、、,30min,TiO2SiO2。,30min。,。5℃/min700℃2h,,。TiO2/SiO2。1.2　TiO2/SiO2,,Fe(NO3)32,40min,。3,0.75%,1.0%,2.0%(n(Fe)∶n(Ti))。0.75%Fe/TiO2/SiO2,1.0%Fe/TiO2/SiO2,2.0%Fe/TiO2/SiO2。1.3　①:(010873);(A3040301):20020701;:20021118:　(1976),,.:　,,81;:02087628187;Email:[e-mail]:10.19476/j.ysxb.1004.0609.2003.03.052H-800,10。、D/MAX-ⅢAX(Cu,30kV,30mA,λ0.15418nm)。PHIQuantum2000Scan-ningESCA,XAlKα,XPS(C1s285.38eV)。1.4　125W(365nm),1,、、、。10mg/L400mL0.36g,30min,,/,,2min,30min,。2　2.1　TEM2TEM,2(a),2(b)1.0%Fe。2(a),,,;21　Fig.1　Photocatalyticreactor(b)。Fe,,。2(a),(b)10:TiO2/SiO214.3nm,1.0%Fe/TiO2/SiO227.8nm。2.2　XRD3FeX。,700℃TiO2,,TiO2/SiO2。SiO22　TEMFig.2　TEMmorphologeisofphotocatalysts(a)—Unmodified;(b)—ModifiedbyFedeposition·794·　　　　　　　　　　　　　　　　　　　　200363　FeXRDFig.3　XRDpatternsofphotocatalystswithdifferentcontentofFeTiO2。1Fe,Scherrer:D=KλBcosθ　Dhkl(nm),λ=0.15418nm,K=0.89,B,θ。Fe,,TEM。,,,,,,。,,,Fe3+Fe2+,,。1　FeTable1　GrainsizesofphotocatalystswithdifferentcontentofFePhotocatalystTiO2TiO2/SiO20.75%Fe/TiO2/SiO21%Fe/TiO2/SiO22%Fe/TiO2/SiO2Grainsize/nm30.010.011.912.012.32.3　(MB)(4)。44　(MB)-ln[ρ(MB)/ρ0(MB)]Fig.4　Relationbetween-ln[ρ(MB)/ρ0(MB)]anddegradationtimeinMBdegradation1.0%Fe,2.0%Fe。,、、[79]。,Fe。[7,10,11]Fe,/,,。,。,。,。,Fe3+,,Fe2+。,Fe2+Fe3+,。Fe2+/Fe3+Ti3+/Ti4+,Fe3+Ti4+,。Fe,Fe3+Fe2+,Fe3+,Fe2+,,,。Fe,,,。3　TiO2/SiO2,SiO2·795·133　　　　　　　　　　　　　　　,:TiO2/SiO2TiO2,TiO2,TiO2,。TiO2/SiO2。,Fe,,1.0%,。REFERENCES[1]　AkiraF,TataNR,DonaldAT.Titaniumdioxidephoto-catalysis[J].JPhotochemPhotobiolC,2000,1:121.[2]　FuX,ClarkLA,YangQ,etal.Enhancedphotocatalyticperformanceoftitania-basedbinarymetaloxides:TiO2/SiO2andTiO2/ZrO2[J].EnvironSciTech,1996,30:647659.[3]　DENGZhong-sheng,WANGJue,ZHONGYu-long,etal.PreparationandphotocatalyticactivityofTiO2-SiO2binaryaerogels[J].NanostructuredMaterials.1999,11:13131318.[4]　VamathevanV,TseH,AmalR,etal.EffectsofFe3+andAg+ionsonthephotocatalyticdegradationofsucroseinwater[J].CatalToday,2001,68:201211.[5]　LIXZ,LIFB.StudyofAu/Au3+-TiO2photocatalytstowardvisiblephotooxidationforwaterandwaste-watertreatment[J].EnvironSciTechnol,2001,35:23812387.[6]　LIFB,LIXZ.Photocatalyticpropertiesofgold/goldionmodifiedTiO2forwastewatertreatment[J].ApplCatalA,2002,228:1521.[7]　ChoiW,TerminA,HoffmannMR.Theroleofmetaliondopantsinquantum-sizedTiO2:correlationbetweenphotore-activityandchargecarrierrecombinationdynamics[J].JPhysChem,1994,98:1366913713.[8]　LitterMI,NavioJA.Photocatalyticpropertiesofiron-dopedtitaniasemisonductors[J].JPhotochemPhotobiolA,1996,98:171183.[9]　SerponeN,LawlessD.Photodegradationofsurfactants—Ⅱζ-potentialmeasurementsinthephotocatalyticoxidationofsurfactantsinaqueousTiO2dispersions[J].Langmuir,1994,10:643650.[10]　DhananjeganMR,KandavelnV,RanganathanR.AstudyonthephotocatalyticreactionsofTiO2withcertainpyrimi-dinebases:effectsofdopants(Fe3+)andcalcinations[J].JMolecularCatalA:Chem,2000,151:217223.[11]　ChoiW,TerminA,HoffmannMR.Effectsofmetal-iondopantsonthephotocatalyticreactivityofquantum-sizedTiO2particles[J].AngewChem,1994,106:11481156.InfluenceofFedepositiononphotocatalyticactivityofTiO2/SiO2compositephotocatalystHUANGCong1,WANGLiang-yan1,XUYue-hua1,LIXin-jun1,ZHENGShao-jian1,LIFang-bai1,2(1.GuangzhouInstituteofEnergyConversion,ChineseAcademyofSciences,Guangzhou510070,China;2.GuangdongKeyLaboratoryofAgriculturalEnvironmentPollutionIntegratedControl,GuangdongInstituteofEco-EnvironmentandSoilScience,Guangzhou510650,China)Abstract:TiO2/SiO2compositephotocatalystismodifiedwithFeusingdepositingmethod.ThephysicalandchemicalcharacteristicsofthemodifiedphotocatalystweredescribedbyX-raydiffraction(XRD)measurement,transmissionelectronmicroscopictechnique(TEM)andmethyleneblue(MB)degradation.Accordingtocrystalfieldtheory,Fe3+isbeneficialtophoto-inducedelectronstrappingandmigrationwhileFe2+canimprovethechargeseparationbytrappingthephoto-inducedholes.WiththecoexistenceofFe2+andFe3+,theactivityofmodifiedphotocatalystisenhancedgreatly.Theresultsshowthatthepropertiesofmodifiedphotocataystsbydepositionaremoresuperiorthanthatofun-modifiedoneandtheoptimumdepositionquantityis1%(n(Fe)∶n(Ti)).Keywords:TiO2/SiO2;deposition;Fe(　)·796·　　　　　　　　　　　　　　　　　　　　20036