改性纳米TiO2光催化氧化还原性能的研究

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1、天津大学博士学位论文改性纳米TiO<,2>光催化氧化还原性能的研究姓名：吴树新申请学位级别：博士专业：工业催化指导教师：秦永宁20030701ABSTRACTPhotocatalysisisanattractiveapproachforenvironmentalprotection，energytransformationandfunctionalgrouptransformationbecauseofitsadvantagesuchaslow．temperature，nonenergyintensityandnon-pollution．Photocatalystsisthekeypart

2、inphotocatalysis，andfurtherimprovementonitsactivityandefficiencybyselectivesurfacetreatmentbymodifyingthepropertiesoftheparticlesisanessentialsteptOapplythisnoveltechnology．Inthisdissertation，thephotocatalyticactivityandsurfacepropertiesofmodifiednanocrystallineTi02havebeencharacterizedbyXRD，SEM，T

3、EM，XPS．Themechanismofimprovementonphotoactivitywasdiscussedbasednotonlyoxidationbutalsoreductionproperties，andtherelationshipbetweenthemwereanalyzed．NanocrystallineTi02withanatasephasewaspreparedatroomtemperaturebyinflictingultrasonicirradiation．Quantumsizeeffectappearsinphotocatalyticoxidationand

4、reductionwhenparticlessizeislessthan20nm．DopednanocrytstallineTi02withtransifionmetalionssuchasCr,Mn，Fe，Co，Ni，Cuwerepreparedbysonic-immersionmethodandwerecharacterizedwithXPS．Theresultsshowthatdopingionswimvariablevalancefacilitatethetrappingofexcitedelectronsandsubsequentinterracialelectrontransf

5、erSOthatithasadvantageoverdopingionswithsinglevalancereferringtothephotocatalyticactivityinoxidationandreduction．AvolcanoprofileswasfoundbetweentheactivityandEa／rwhichrepresenttheabilitytotrapexcitedelectrons，andthecatalystdopedwithcopperionswhichhasamoderatevalueofEa／rshowsthebestactivityinphotoc

6、atalyticoxidationandreduction．Theactivityofadsorptionoxygenonthesurfaceofcatalystaffecttheefficiencyoftrappingelec拄onSOastoaffecttheperformanceinoxidation．Dopedcatalysts、砘thcopperionbydifferentmethodswerepreparedandcharacterizedwithXPS，XRD，SEM，TEM．Theresultsshowthatthedistributionandvalanceofcoppe

7、relementisdifferentamongthesesamples．BecauseofthehighdispersionandhighervalueofCu+／CU2+onthesurfaceofcatalystpreparedbysonic—immersionmethods，itsphotocatalyticactivityishigherthananyothersamplespreparedbyhydrolys