CuO-TiO-2-H-2O-2光催化体系中亚甲基蓝脱色机理

326Vol.32No.620096JournalofChongqingUniversityJun.2009:10002582X(2009)062705206CuO/TiO22H2O2,,,,(,400030):2009202206:(50278101);(20070611009);(200904A1B0010316):(19642),,,,,(E2mail)[e-mail]:CuO/TiO2pH#OH,,#OH,#OH;#OH,#OH;3,,pH#OH#OH,;,#OH,,:;;CuO/TiO2;:X703.1:AThedecolorationmechanismofMethyleneBlueinaCuO/TiO22H2O2photocatalyticsystemJIFang2ying,XUXuan,FANZi2hong,QIUYan,YUANYun2song(KeyLaboratoryoftheThreeGorgesReservoirRegion.sEco2environment,MinistryofEducation,ChongqingUniversity,Chongqing400030,P.R.China)Abstract:ACuO/TiO2photocatalystispreparedusingthehydrolysismethod.ItexhibitesexcellentphotocatalyticactivityunderbothUVandVislight.AfterinvestigatingthequantityofhydroxylradicalsandthedecolorationrateunderdifferentpHsituationsirradiatedbyUVorVislight,anewmethylene(MB)bluephotocatalyticdecolorationmechanismisproposed.UnderUVlightirradiation,methyleneblueisdecoloredbymasshydroxylradicalswhichdiffuseintotheliquidphaseinacidicconditions.Afewhydroxylradicalsaregeneratedinalkalineconditions,andtheseradicalsaffecttheMBwhichisabsorbedonthephotocatalystsurface.Thereisasynergisticeffectoftheaboveinneutralconditions.Theremovalrateunderstronglyacidic,stronglyalkalineorneutralconditionsismuchhigherthaninweakacidoralkalineconditions.UnderVislightirradiation,fewerhydroxylradicalsexistinthissystemforanelectron2transferformationloop,andthehydroxylradicalsmustdiffuseintoliquidtoreactwithMB,sothedecolorationratesareextremelylowunderacidicandneutralconditions.AhighdecolorationrateisachievedunderstronglyalkalineconditionsbecauseMBisabsorbedonthesurfaceofthephotocatalystwhichincreasesthehydroxylradicalutilizationefficiency.Photosensitizationalsoacceleratesthedecoloration.Keywords:photocatalysis;hydroxylradical;CuO/TiO2;methyleneblue1976Cary[1]TiO2,TiO2[229],H2OCO2,Hoigne[10],#OH,,#OH[11212],,,#OH,11.1:();();();,();30%H2O2:F27000(Hitachi);ASAP2010();X();721E();PHS23CpH();ZY32150(,365nm)1.2CuO/TiO2Ti(OC4H9)4(A);(B)BA,0.5mol/L4.0mol/L1.5mol/L,2d,,600e5h,TiO2TiO2,100e,,500e4h,CuOTiO2,CuO/TiO2CuOTiO2BET,0.1molCuO/100m2TiO2BET181m2/g,5~8nmX,XRD1JcpdsTiO219.83nm1ab,CuO/TiO2TiO2CuOCuOCuO,2DegussaP25TiO2CuO/TiO22TiO2DegussaP25,,CuO/TiO2,890nm2CuOTiO21TiO2CuO/TiO2XRDa2TiO2;b2CuO/TiO22CuO/TiO2,TiO2P251.31000mL,1000mL,,2h,30min1,pH3~11,pH,665nm,665nm70632#OH[11]22.110001000mL0.1gTiO20.1gCuO/TiO2,10mLH2O2,UVVis2hpH3~63TiO22H2O2pH4TiO22H2O2pH5CuO/TiO22H2O2pH6CuO/TiO22H2O2pH34,CuO,TiO2(pH=3)(pH=11),(pH=11),TiO2H2O2[13],,56,CuO,(pH=311)(pH=7),(pH=5689),,,pH3456,2,CuOTiO22,2,,2(2)2.2#OH,#OH#OH,pH#OH721078,TiO22H2O2,#OHpH,;#OH7076,:CuO/TiO22H2O2910,CuO/TiO22H2O2,#OH,;#OH,30min,2#OHpH,7TiO22H2O2#OHpH8TiO22H2O2#OHpHTiO22H2O2CuO/TiO22H2O2,,#OH,,#OH,pH#OH,pH,CuO/TiO22H2O2,#OH2,9CuO/TiO22H2O2#OHpH10CuO/TiO22H2O2#OHpH60min#OH2.3[10]#OH#OH5pH3711,2h(85%~90%),3#OH(9),,TiO2,,;,OH-,TiO2,,70832[14]3:1#OH;2#OH;33,CuO/TiO2,2.3.1292nm,,TiO2,TiO2CuOTiO2,CuO,TiO2,2#OH,#OH,#OH2(9)11,,#OH,,,,,,#OH,#OH,,#OH,,pH,,2.3.212,CuOTiO2(dye+#),,CuO,CuOO2,O2TiO2#OH[15216]CuOO2,,#OH,,CuOTiO2,H2O2#OH,,,#OH#OH21112pH,#OH,#OH,,,pH,#OH,,,,[17218]31)CuO/TiO22H2O2,,,;,2)CuO/TiO22H2O2,2#OH:;;7096,:CuO/TiO22H2O2,#OHpH,;,,3),,:[1]CAREYJH,AWRENCEJ,TOSINEMH.PhotodechlorinationofPCBsinthepresenceoftitaniumdioxideinaqueoussolutionsBull[J].EnvironContamToxicol,1976,16:6972701.[2]BRILMYER,GEORGEH,FUJISHIMA,etal.Photothermalspectroscopy[J].AnalyticalChemistry,1977,49(13):205722068.[3]ENRICB,EVAM,ROSERS,etal.AnilinemineralizationbyAOPps:anodicoxidation,photocatalysis,electro2Fentonandphotoelectro2Fentonprocesses[J].AppliedCatalysisB:Environmental,1998,16(1):31242.[4]TERUHISAO,MIYAKOA,TSUTOMUU,etal.PreparationofS2dopedTiO2photocatalystsandtheirphotocatalyticactivitiesundervisiblelight[J].AppliedCatalysis,2004,265(1):1152121.[5],,,.[J].,2005,18(3):43245.QIAOSHI2JUN,ZHAOAI2PING,XUXIAO2LIAN,etal.StudyonammonianitrogeninwastewaterdegradationbyTiO2photocatalysis[J].ResearchofEnvironmentalSciences,2005,18(3):43245.[6],,,.TiO2[J].,2007,27(3):4042408.YANGLI2PING,LIUZHEN2YAN,SHIJIAN2WEI,etal.OptimalfilmthicknessofTiO2coatedonfoamnickelsforthephotocatalyticdegradationofformaldehyde[J].ChinaEnvironmentalScience,2007,27(3):4042408.[7],,,.Mo2TiO2/ACL2[J].,2007,28(8):174621751.WANGYU2PING,YUANJUN2XIU,LIJIE,etal.PreparationofMo2TiO2/activatedcarbonanddegradationofL2acidundervisiblelight[J].EnvironmentalScience,2007,28(8):174621751.[8],,,.TiO22SBR[J].,2007,27(9):144421450.XUGAO2TIAN,XIAOHUA,ZENGXU,etal.DyestuffwastewatertreatmentbycombinedphotocatalysisandSBR[J].ActaScientiaeCircumstantiae,2007,27(9):144421450.[9],,,.TiO2[J].,2006,19(2):95299.SHIZAI2FENG,RENXUE2CHANG,KONGLING2REN,etal.ExperimentalstudiesontheTiO2photocatalyticmembranereactor[J].ResearchofEnvironmentalSciences,2006,19(2):95299.[10]HOIGNEJ,BADERH,HAAGWR,etal.Rateconstantsofreactionsofozonewithorganicandinorganiccompoundsinwater)IIIinorganiccompoundsandradicals[J].WaterResearch,1985,19(8):99321004.[11],,,.[J].,2005,63(18):176521768.ZHANGWEN,WANGXU2XU,LINHUA2XIANG,etal.Influenceofmagneticfieldontheformationrateofhydroxylradicalinpho