SnO2-basedR134agassensor－Sensingmaterials

preparation,gasresponseandsensingmechanism

（SnO2基R134a氣體傳感器：傳感材料的制備，

氣體響應(yīng)和傳感機(jī)理）成員：李月飛201213316

郭建軍201213325作者介紹：陳俊琛，2008年獲得上海大學(xué)應(yīng)用化學(xué)專業(yè)學(xué)士學(xué)位。此后，她繼續(xù)攻讀上海大學(xué)無(wú)機(jī)化學(xué)理科碩士學(xué)位。目前，她主要研究方向是合成以SnO2和Al2O3材料的介孔結(jié)構(gòu)以及其在氣體傳感器中的應(yīng)用。徐甲強(qiáng)，1988年畢業(yè)于中國(guó)科技大學(xué)材料科學(xué)系，并獲理學(xué)碩士學(xué)位。2005年獲得上海大學(xué)材料科學(xué)博士學(xué)位。他研究方向包括氣體傳感器，納米材料的合成和應(yīng)用。Contents：AbstractIntroductionExperimentalResultsanddiscussionConclusionsContents：AbstractIntroductionExperimentalResultsanddiscussionConclusions

Abstract：

◆TheexperimentalresultsindicatedthattheresponsetowardsR134a

oftheSnO2-based

gassensorcanbesignificantlyenhancedbyloadingnoblemetalandusingcatalyticcoating.◆ThesensorbasedonadoublelayerfilmSnO2(Au)/Al2O3(Au)showedsatisfactoryresultsincludinglargeresponse,goodselectivity,highlong-termstability,fastresponseandrecovery,revealingitspotentialapplicationinthedetectionofrefrigerantsandthemaintenanceofairconditionsystems.（基于雙層薄膜SnO2（Au）/zAl2O3（Au）的傳感器展示出令人滿意的結(jié)果，，，顯示出其在制冷劑檢測(cè)及空調(diào)系統(tǒng)維護(hù)方面有應(yīng)用潛力。）

補(bǔ)充：

氣體傳感器定義：能夠采集氣體的某些信息（如：濃度、種類）并把采集到的信息轉(zhuǎn)化為人們更易識(shí)別的信號(hào)（如電信號(hào)、聲信號(hào)、光信號(hào)、數(shù)字信號(hào)等）,凡是具有這種功能的部件或裝置，就是氣體傳感器。Contents：AbstractIntroductionExperimentalResultsanddiscussionConclusions

Introduction：

WedisclosethatSnO2sensorsdecoratedbyAu-,Ag-,Pt-loadingandAl2O3catalystcoatingwereusedtoimprovetheresponsetoR134a.TheresultsindicatethatthenewtypeofgassensortowardsR134awithlargeresponse,goodselectivity,highlong-termstability,fastresponseandrecoverycanbeobtained.（結(jié)果表明，新型氣體傳感器對(duì)R134a的響應(yīng)大，選擇性好，長(zhǎng)期穩(wěn)定性高，響應(yīng)快和可恢復(fù)。）Contents：AbstractIntroductionExperimentalResultsanddiscussionConclusions

Experimental：

Fig.1.Sketchofthegassensorstructure.Contents：AbstractIntroductionExperimentalResultsanddiscussionConclusions

Structureandmorphology：

Fig.2.TEMimagesofSnO2.

Structureandmorphology：

Fig.3.TEMimagesofporousAl2O3.

Structureandmorphology：

Fig.4.SEMimagesofSnO2.

Speculateone：

●Basedontheseobservations，wespeculatethatmesoscopicporesmayprovidemoregaschannelsandimprovetheefficiencyintransportationofgases,whichisafavourablefeatureforgassensing.（基于這些觀察，我們推測(cè)，介觀孔可以提供更多的氣體通道提高運(yùn)輸氣體的效率，這是氣體傳感一個(gè)有利的特征。）

Structureandmorphology：

Fig.5.Nitrogenadsorptionisothermsandcorrespondingporesizedistribution(inset)oftheporousAl2O3annealedat500?C.

Speculatetwo：

●WespeculatethatitisduetotheproperporesizecanR134afragmentsreachtheSnO2layerthroughtheporousAl2O3layer.（我們猜想正是由于有適當(dāng)?shù)目讖剑琑134a碎片才能通過(guò)多孔氧化鋁層到達(dá)到SnO2層.）

Gas-sensingproperties：

Fig.6.Theresponseto100ppmR134aofSnO2withandwithoutCl?atdifferentpHandtheresponsesto100ppmR134aoffourkindsofsensorsatdifferentworkingtemperature(inset).

Conclusionone：

★WeobservedthatSnO2withoutcontainingCl?hadhigherresponsethanthatofSnO2containingCl?;bothofthetwoseriesofSnO2obtainedatpH=3hadthelargestresponse.Conclusiontwo：

★TheresultssuggestthatSnO2(Au)/Al2O3(Au)hastheoveralllargestresponse;itsresponsevaluetowardsR134aat100ppmreachesashighas8.7.（結(jié)果表明,SnO2(Au)/Al2O3(Au)整體響應(yīng)最大;在100ppm時(shí)，對(duì)R134a的響應(yīng)值高達(dá)8.7。）

Theresultsrevealthatthegassensorsallreachtheirhighestresponseat350?C,sowechoose350?Casanoptimalworkingtemperature.

（350?C最佳響應(yīng)溫度。）Gas-sensingproperties：Fig.8.StabilityofSnO2(Au)/Al2O3(Au)to100ppmR134a.Conclusion：◆ThestableresponsevalueindicatesthatthesensorbasedonSnO2(Au)/Al2O3(Au)exhibitshighlong-termstability.（這些穩(wěn)定的響應(yīng)值表明,基于SnO2(Au)/Al2O3(Au)的傳感器具有長(zhǎng)期穩(wěn)定性高的特性。）Gas-sensingproperties：Fig.9.ResponseofSnO2(Au)/Al2O3(Au)todifferentgasesat100ppm.Conclusion：◆Wegettheconclusionthatthesensorshaveafairselectivity,butsomeissueswithseveralinterferences(ethanol,acetoneandsoon)stillexist.（公平選擇性，存在干擾因素如乙醇，丙酮等）Gas-sensingproperties：■Tosumup,thesensorbasedondoublelayerfilmofSnO2(Au)/Al2O3(Au)showssatisfactorysensingpropertiesforR134adetection.IthaspromisingprospectinmonitoringtheleakageandconcentrationoftheR134aescapedduringtheproductionandapplicationofrefrigerants.（總之,SnO2(Au)/Al2O3(Au)傳感器對(duì)R134a檢測(cè)顯示了滿意的傳感性能。其在制冷劑檢測(cè)及空調(diào)系統(tǒng)維護(hù)方面有應(yīng)用潛力。）Gas-sensingmechanismofR134a：Fig.10.FT-IRspectraofSnO2beforeandaftercalcinatingat350?CinR134a.（橫：波數(shù)：縱：透射度）Speculate:★TheFT-IRspectrumshowninFig.10displaysnosignificantdifferencebeforeandaftercalcinatingtheSnO2at350?CunderR134a,becausethatthepeakdisplayedintherangeof4000–3500cm?1belongstoH2O,andthepeakintherangeof1000–500cm?1isthebondofSn–O.（沒(méi)明顯差異，峰值范圍）Gas-sensingmechanismofR134a：Fig.11.FT-IRspectraofAl2O3beforeandaftercalcinatingat350?CinR134a.Speculate:★TheFT-IRspectrumshowninFig.11demonstratesanobviouschangeintherangeof500–1000cm?1beforeandaftercalcinatingtheAl2O3at350?CunderR134a.Thischangema