半导体氧化物气敏材料热稳定性-研究

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1、摘要TEOS改性效果更加显著，经过KH．550改性的Sn02在1000。C下粒径只有10nm。通过Si02的表面修饰，Sn02气敏性能也显著提高，对H2灵敏度由5．4提高到37．5。关键词：二氧化锡气敏材料热稳定性AbstractGassensorsarewidelyusedinthefieldsofpetrochemical，securitymonitoring，aerospace，environmentalmonitoringandSOon．Semiconductormetaloxides-arewidelyusedasgas-sensingmaterials，becau

2、seofitshighsensitivitytoflammableorexplosivegasesandtoxicgases．Nanometersemiconductoroxidegas—sensingmaterialshaveexcellentgas-sensingproperties，suchashighsensitivityandlowoperatingtemperature．However,theysuffertheseriousproblemofsinteringandgraingrowthatrelativelymoderatetemperatureswhicht

3、hesensorsworkat，withsubsequentlossofnanocrystallinebehaviour．Thusimprovementoftheirthermalstabilityiscrucialtoensureexcellentgas-sensingpropertiesofthenanomaterials．ThemainfocusofthispaperistoimprovethethermalstabilityofnanometerSn02byinhibitingthegrowthofnanocrystallineSn02withmodification

4、．Themaincontentsareasfollows：(1)Tetraethylorthosilicate(TEOS)，asthemodifier,reacted淅thhydroxylsofSn02intoluenesolvent．Si02wasgraftedonthesurfaceofSn02toimproveitsthermalstabilitybyinhibitingthegrowthofthenanocrystallineSn02athightemperature．TheaverageparticlesizeofmodifiednanometerSn02is30n

5、tocalcinationatI000。C．However,thatofpureSn02is95nmatthesamecalcination．SogrowthofnanocrystallineSn02isrestrictedupto1000℃．(2)KH一550，usedasamodifiertoreactedwithhydroxylgroupsonthesurfaceofSn02，canrestrictthegrowthofnanocrystallineSn02．TheprocessofKH．550modificationisoptimized，andthegas—sens

6、ingperformancewasstudiedunderdifferentprocessconditions．Theoptimalexperimentalparameterswereasfollow：KH一550／SnOz(wt％)=9％，react3hatroomtemperature．Undertheseconditions，wepreparedmodifiednanometerSn02，whichgassensitivityis37．5to1000ppmH2．Andtheintroductionofthesecondphase(Si02)percentageisonl

7、y1．74％．(3)As—synthesizedsampleswerecharacterizedbyFT-IR，XRD，SEM，andTEM．Atthesametime，thermalstabilityofmodifiednanometerSn02wasanalyzed．TheIIIresuItsshowthatthewell．dispersedSi02remainsstronglybondedattheSn02surfacet11roughSn-O．Sibonds．KH．550，asamodifier