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ID:33099503
大小:7.13 MB
页数:91页
时间:2019-02-20
《二氧化钛纳米晶自支撑连续纤维的制备、表征与其光催化性能》由会员上传分享,免费在线阅读,更多相关内容在行业资料-天天文库。
1、二氧化钛纳米晶自支撑连续纤维的制备、表征及其光催化性能byimprovedsol—gelmethodwithoutanytemplate.Thefiberwasabove1metrelongwithadiametreof10~50pan.Thesubstratewerecomposedoftitaniananocrystalsandpores.Themorphorlogy,surfaceareaandporestructurewerecontrolledbyadjustingSicontent.
2、Theproductcalcinedunder7006Chasthelargestspecificsurfaceareaandporevolume:127.7m2/gand0.25cm3/g.whilethemoleratioofSi/TiisO.15AnditexhibitesthehighestphotocatalyticactivityforthedegradationofX-3B.Itmainlyattributestoperfectanatasecrystalstructure,lar
3、gespecificsurfacearea,porevolumeandstrongabsorptiontoUVlight.ThekineticdataandadsorptionisothermfortheadsorptionAs(V)accordedwithpseudo-secondrateequationandFreundlichequation.Adsorptionwasdominantwithstaticgravitation.Adsorptionisothermfortheadsorpt
4、ionAs(IⅡ)wasinagreewithFreundlichequation,andsurfacecompoundplayeddominanteffect.Photocatalysismadebacteriainactivationunderultravioletlight,andrestrainedbacteriaincreasingwithoutultravioletlight.Inthethirdsection,puretitaniacont.inuousfiberswithabun
5、dantsurfacedefect(Ti3+)werepreparedusinginexpensivetitaniumtetrachlorideandtetraethylorthosilicateasTiandSisourcethroughsol—gelprocesscombiningsteamheattreatment.Atlowtemperature,steamiscatalysttoacceleratenucleationandcrystallization.Meanwhile,abund
6、antsurfacedefect(面3+)werecteatedthroughone·—stepcrystallizationavoidinghighenergyandtimeofconventionaltwo··stepcrystallization.ComparedtoP25,theabsorptionedgeofpuretitaniafibresappearedredshift.Itsabsorptionintensityincreasesby40%inthewavelengthlarge
7、rthan400nm.Itexhibithighphotocatalyticactivity.ThemainreasonmaybethatTi”surfacestatewas0.3eVbelowtheconductionbandoftitania.Soitcancapturethephotoelectronintheconductionband,increasephotoinducedchargeseparation,decreaseelectron—holerecombination,ande
8、nhancethephoto—catalyticefficiency.Thenewenergyband-oxygenvacancystate(2.02~2.45eV)wasformedabovevalancebandwhichiscorresponding506-614nm.Sothecatalystcanabsorbvisiblerays.Nevertheless,thedopingofSirestrainedtheformationofTi3+andoxygenvacancyresultin
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