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1、納米Ti02/Si02復合粉體的制備及光催化降解性能的研究摘要近年來,利用半導體凈化技術(shù)日益引起人們的重視。納米Ti02顯示出較強的光催化降解性能,它能降解廢水廢氣,殺死細菌病毒,可以用于廢水處理、凈化空氣等領(lǐng)域。對Ti02進行改性,并應(yīng)用于環(huán)保領(lǐng)域,具有極大的現(xiàn)實意義。本文采用溶膠一凝膠法制各了納米Ti02粉體和Ti02/Si02復合粉體。采用XRD、XPS、FT—IR、BET等現(xiàn)代測試技術(shù)分析研究了所制粉體的微觀結(jié)構(gòu)、組織性能;探討了熱處理溫度、摻雜量等因素對相組成、相變及晶粒尺寸的影響,以及這些因素對Ti02/Si02復合粉體光催化降解性能的影響。研究結(jié)果表明:
2、用溶膠一凝膠法可以制得納米Ti02粉體和Ti02/Si02復合粉體:Si02的摻雜量、粉體熱處理時間、熱處理溫度等因素會影響催化劑的光催化降解效率。本試驗條件下,對甲基橙的降解效果最好的是物質(zhì)量比為n(Ti):n(Si)=3:1,550"C焙燒2h的復合粉體,光照2h后降解率達到64.85%,相同條件下,單一Ti02粉體不到15%。實驗證明,選擇合適的摻雜劑量、熟處理溫度,可以大大提高Ti02的光催化降解性能。關(guān)鍵詞:Ti02/Si02復合粉體:光催化劑;二氧化鈦;溶膠一凝膠;甲基橙AStudyonthePreparationofNanometerTi02/Si02C
3、ompositePowderandItsPhotocatalytieActivityAbstractInrecentyears.semiconductorphotocatalystshaveevokedtremendousinterestinlight—stimulateddegradation.NanometerTi02photocatalysthasbeenprovedtohaveoutstandingperformance.Itcalltreatwastewaterandexhaustgas,killbacteriaandviruses.SoitCallbeus
4、edtotreatwasteliquids,purifyair.a(chǎn)ndetc.Thus,ithasgreatpracticalvaluetoimprovethephotocatalyticperformanceofTitaniaandapplyittoenvironmentalprotection.Inthepaper,Ti02andTi02/Si02compositepowdersweremadebysol-geltechniquebasedonthepredecessor’Sstudies.Thecomposition,micro·structureandprop
5、ertiesofthepreparedTi02/Si02powderswerecharacterizedbyXRD,XPS,BET,F(xiàn)T-IR,andSOon.Theeffectsofcompositionandheattreatmentonthetransformationtemperaturebetweentheanataseandrufflephase,aswellasthedopingofSi02onthephotocatalyticdegradationofmethylorangewereexamined.Resultsshowedthatthesizeof
6、dopedTi02powderswasintherangeof1-50Din.AndtheirphotoeatalyticperformancewasaffectedbytheamountofSi02dopant,heattreatmenttemperature,andothers.TheSi02dopedTi02heattreatedat550℃demonstratedthehighestphotocatalyticperformance:methylorangesolutionwas64.85%decomposedin2hour.comparingtothaton
7、lyabout15%decomposedwithoutSi02.ProperSi02dopingandheattreatmenttemperaturecangreatlyimprovephotocatalyticperformanceoftitania.KeyWords:Ti02/Si02compositepowders,photocatalyst,titania,sol—gel,methylorange插圖清單圖1.1銳鈦型和金紅石型晶型結(jié)構(gòu)圖???????????????????7圖1.2Ti02/Si02表面Lewis酸位的增加????????