资源描述：
《Iodine-Doped TiO2 Photocatalysts Correlation between Band Structure and Mechanism》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。
1、14948J.Phys.Chem.C2008,112,14948–14954Iodine-DopedTiO2Photocatalysts:CorrelationbetweenBandStructureandMechanismSachikoTojo,TakashiTachikawa,MamoruFujitsuka,andTetsuroMajima*TheInstituteofScientificandIndustrialResearch(SANKEN),OsakaUniVersity,Mihogaoka8-1,Ibaraki,
2、Osaka567-0047,JapanReceiVed:June5,2008;ReVisedManuscriptReceiVed:July7,2008Iodine-dopedTiO2powders(I-TiO2)preparedviahydrothermaltreatmenthaveabsorptionintheregionofultraviolet(UV)andvisiblelight,andwereusedasaphotocatalystwithirradiationofUVorvisiblelight.TheI-Ti
3、O2powderswerecharacterizedbyXRD,TEM,EDS,XPS,FTIR,andsteady-stateUV-visdiffusereflectancespectra(DRS),andtheirphotocatalyticactivitieswereinvestigatedbasedonthephotodegradationof4-chlorophenol(4-CP)inwater.Ahigherphotodegradationefficiencyof4-CPwasobservedforI-TiO2un
4、derUV-andvisible-lightirradiation,whencomparedtotheundopedTiO2.Thetransientbehaviorofthephotogeneratedchargecarriers,suchastrappedelectrons(e-)andholes(h+),andtheone-electronoxidationdynamicsofsubstratesduringUVorvisiblelaserflashphotolysisofundopedTiO2andI-TiO2pow
5、derswereinvestigatedusingtime-resolveddiffusereflectance(TDR)spectroscopy.Thetimeevolutionoftransientsignalsindicatedthatthelong-livedphotogeneratedh+wereformeduponthelaserexcitationofI-TiO2powders,whilenotrappede-wereobserved.Fromtheexperimentalresults,itissuggest
6、edthattherecombinationofe--h+pairsisinhibitedbecausethedopingIsitesactastrappingsitetocapturethee-duringtheI-TiO2photocaltalyticreaction.Furthermore,thetrappedh+generatedinI-TiO2havenosignificantoxidationreactivitytowardsubstrates,suchasaliphaticandaromaticcompound
7、s,adsorbedonthesurfaceunderbothUV-andvisible-lightirradiation.Introductionsuchasmethanol(CH3OH)andaromaticsulfides.24-26Ontheotherhand,thereductionpropertiesorindirectoxidationTheefficientutilizationofsolarenergyisoneofthemajorpropertiesviareactionswithsurfaceinterm
8、ediatesduetooxygengoalsofmodernscienceandengineeringthatwillhaveagreatreductionorwateroxidationwouldbemaintaineduponirradia-impactontechnologicalapplica
