二氧化钛固载杂多酸催化剂的制备及其光催化性能研究孙亚萍

204No.4Vol.2020068JournalofChemicalEngineeringofChineseUniversitiesAug.20061003-9015(2006)04-0554-051,2,1,1,1,11.,710049;2.,100871TiO2⎯⎯H3PW12O40/TiO2H8SiW12O42/TiO2H7PMo12O42/TiO2HammettTiO2TiO23RTiO279%91%TiO20.10mol⋅L−128h120650W40minHPA-TiO2TiO2O2TiO23RX703TQ085TQ032.4TQ426.61APreparationandPhotocatalyticActivityofHeteropolyacidSupportedonTitaniumDioxidePhotocatalystsSUNYa-ping1,ZHAOLiang2,ZHAOJing-lian1,HOUYong-ping1,CHONGFa-guo1,LIANGYong11.EnvironmentalEngineering,Xi’anJiaotongUniversity,Xi’an710049,China;2.SchoolofPhysics,PekingUniversity,Beijing100871,ChinaAbstract:ThreekindsofheteropolyacidHPAsupportedontitaniumdioxide(TiO2)photocatalystsH3PW12O40/TiO2,H8SiW12O42/TiO2,andH7PMo12O42/TiO2werepreparedseparatelybyimmersingTiO2powderineachcorrespondingaqueoussolutionofHPA,andthenagglomeratedatacertaintemperature.TheacidintensitiesofsupportedHPAphotocatclystsweredeterminedbyHammettindicatorassociatedwithUVspectrum.TheeffectsofthekindsofHPA,immersingtime,concentrationofHPAaqueoussolution,thetemperatureandmodeofagglomerationontheacidintensityofthesupportedHPAphotocatalystswereinvestigated.ThesupportedHPAphotocatalystswerecharacterizedbyIRspectrumandtheirphotocatalyticactivitiesweremeasuredbythephotodegradationexperimentsofacidbrilliantred3R.ResultsshowthatHPAisloadedonthesurfaceofTiO2anditcausesthepreparedcatalysthashigheracidintensity.ThesupportedHPAphotocatalystspreparedhavehighercatalyticactivitiesthanthatofunloadedTiO2,anditsphotodegradationefficiencyforacidbrilliantred3Risincreasedfrom79%to91%.AmongtheabovementionedthreekindsofHPA/TiO2photocatalysts,thecatalyticactivityofH3PW12O40/TiO2isthehighestwhenitspreparationisunderfollowingconditions:theconcentrationofH3PW12O40aqueoussolutionis0.10mol⋅L−1,immersingtime28h,dryingtemperature12,microwaveagglomerationpower650Wandtime40min,respectively.InthenewphotocatalyticsystemofHPA/TiO2,HPAacceleratestheelectrontransferfromtheTiO2surfacetoO2,whichchangesthecourseofTiO2photocatalysisandimprovesthephotocatalyticefficiency.Keywords:supportedacidphotocatalysts;titaniumdioxide;heteropolyacid;photocatalysis;acidbrilliantred3R2005-04-282005-11-22(20377034)(1981-)[e-mail]204555180%[1]TiO2[2]TiO24%TiO2[3,4]TiO2TiO2[5,6](HPA)[7]TiO2TiO23R22.13R721W(500WTU1800PCUV-VIS60SXR-FTIR2.22.2.1TiO2[8]H2OABAB580400TiO22.2.2TiO22.2.3[5,6]10mL5minH0pKalog[B]/[BH]H0pKaBBH[B][BH]2.2.4TiO2TiO23R500W3R55620068[9]λmax=509nm3R0t0(-)/ECCC=×100%C0Ct33.1TiO23.1.1TiO2TiO2TiO22mL0.04mol⋅L−10.50gTiO224h800W30minH01111TiO2TiO2TiO2TiO23.1.2TiO22mL0.04mol⋅L−10.50gTiO222h24h26h28hTiO2800W30minTiO2H0228h28h3.1.3TiO20.02mol⋅L−10.04mol⋅L−10.06mol⋅L−10.08mol⋅L−10.10mol⋅L−1TiO228hH030.10mol⋅L−1[10]H3PW12O40/TiO2(2)Keggin3004005006007000.00.20.40.60.8Abs/nm123λ/nm1TiO2Fig.1UVspectrumsofdifferentheteropolyacidssupportedonTiO21.H8SiW12O42/TiO2,2.H3PW12O40/TiO2,3.H7PMo12O42/TiO21TiO2(H0)Table1H0ofdifferentheteropolyacidssupportedonTiO2AlkalescentabsorptionAcidabsorptionNo.HPAλ/nmValueλ/nmValueH01H8SiW12O425270.3913060.2710.9592H3PW12O405310.4082550.4020.8063H7PMo12O425370.4703050.3390.9422(H0)Table2H0ofcatalystspreparedunderdifferentimmersingtimesAlkalescentabsorptionAcidabsorptionNo.Immersingtime/hλ/nmValueλ/nmValueH01225190.4062520.3530.8612245310.4182550.4020.8163265190.4312510.4210.8104285240.4172510.4100.8073(H0)Table3H0ofcatalystspreparedbydifferentimmersingconcentrationsAlkalescentabsorptionAcidabsorptionNo.Concentration/mol⋅L−1λ/nmValueλ/nmValueH010.025310.4422550.3890.85520.045250.4372550.3860.85430.065310.3042560.2610.86640.085290.3802560.3590.83650.105430.2702610.2550.824Wavenumbers/cm−12TiO2H3PW12O40/TiO2Fig.2IRspectrumofH3PW12O40/TiO220001600120080040020304050607080Transmittance/%161214019589138697655172045570.10mol⋅L−13.1.4TiO2TiO2TiO2650W30min4002hTiO2H043.1.5TiO2300W500W650W750W850WH05650W3.22TiO21401cm−1Ti-O-TiIR700~1100cm−1958cm−1913cm−1869cm−1765cm−1TiO2TiO2KegginTiO2300mL60mg⋅L−13R0.5gTiO20.5gHPA-TiO23R3HPA-TiO2TiO279%91%3.3TiO2HPA-TiO2[11,12]TiO2·OHKwanKim[13]H3PW12O4TiO2Ozer[14]TiO2-H4SiW12O40TiO2-H4PW12O40TiO2-H4W10O32HPA-TiO2HPAO24H0Table4H0ofcatalystspreparedunderdifferentagglomerationmodesAlkalescentabsorptionAcidabsorptionNo.Agglomerationmodeλ/nmValueλ/nmValueH01Microwaveoven5310.4182550.4020.8162Muffleroaster5270.3933060.2700.9635(H0)Table5H0ofcatalystspreparedunderdifferentagglomerationpowersAlkalescentabsorptionAcidabsorptionNo.Agglomerationpower/Wλ/nmValueλ/nmValueH013505290.3682570.4010.76325005220.3762570.4190.75336505240.3952580.5130.68647505260.3782570.4030.77258505230.3812570.4240.754Reactiontime/min33RFig.3Comparisonofphotocatalyticactivityofdifferentphotocatalystsusedtodegradateacidbrilliantred3R1-TiO2+HPA,2-TiO201020304050607080020406080100E/%124TiO2Fig.4ThephotocatalyticmechanismoftheHPA-TiO2couplingsystemTiO2CBe-h+VBultravioletradiation(400nm)h+•OH•OHH+-0.10+1+2+3+3.1Oxidation-reductionpotentiaHPAoxHPAredO2O2-•Red+RedH2OOH-Ultraviolet(λ400nm)55820068hν+TiO2——e−+h+(1)HPAox+e−——HPAred(2)HPAred+O2——HPAox+O2−(3)TiO2O2TiO2·OH44(1)H3PW12O40/TiO2H8SiW12O42