文档名：Zn2SnO4异质结型气体传感器的构建及其乙醇气敏性能优化机制
摘要：乙醇是一种无色、易燃易爆、挥发性强的有机化合物,属于挥发性有机污染物(VOCs).在人体健康和酒驾检测中是一种重要的标志性气体.采用水热法制备了CaFe2O4、Zn2SnO4和CaFe2O4/Zn2SnO4复合材料,并对晶体结构、元素组成、形貌、光学和电化学性质进行了分析,以及对CaFe2O4/Zn2SnO4的气敏性能进行了研究.结果表明,4%(摩尔分数)CaFe2O4/Zn2SnO4的气敏性能优于Zn2SnO4和CaFe2O4,在400℃4%CaFe2O4/Zn2SnO4对40μmol/L乙醇的灵敏度值为96,响应、恢复时间分别为21s和63s,并具有优异的选择性和良好的稳定性.在此基础上,深入研究了CaFe2O4/Zn2SnO4气敏性能优化的机制.
Abstract：IntroductionEthanolisoneofvolatileorganiccompounds.Long-termexposuringethanolvaporscancauseserioushuman-beinghealthproblems,suchasheadaches,throatirritation,andliverdamagedirty.Inaddition,thehumanbodywillhavenerveparalysis,slowbrainresponse,anduncontrolledlimbswhenethanolinthehumanbloodreachesacertainconcentration,resultinginfrequenttrafficaccidents.Itisthusnecessarytodevelopgassensorsthatcanmonitorethanolinthehumanbody.Metaloxidegassensorshaveattractedmuchattentionbecauseoftheircheapprice,convenientportabilityandstableperformance.Zn2SnO4andCaFe2O4arenovelternarymetaloxidesemiconductorswiththeadvantagesofhighelectronmigrationrate,stronggasadsorptionandgoodthermalstability,whicharewidelyusedingassensors.However,singleZn2SnO4orCaFe2O4generallyhasthedisadvantagesofpoorselectivity,highoperatingtemperatureandlongresponse-recoverytime.Somestudiesindicatethatcombiningtwodifferentmetaloxidestoconstructheterojunctionscouldgreatlyimprovethegassensingproperties.ItisprospectedthattheconstructionofCaFe2O4/Zn2SnO4heterojunctionisaneffectivemethodtoenhancethegassensingperformance.However,littleworkonCaFe2O4/Zn2SnO4compositeforethanoldetectionhasbeenreportedyet.Inthispaper,ap-nheterojunctionbetweenCaFe2O4andZn2SnO4wasconstructedbyahydrothermalmethodtorealizethesuperiorgassensingpropertiesofCaFe2O4/Zn2SnO4compositetodetectethanol.MethodsToprepareZn2SnO4octahedral,2mmolZn(CH3COO)2?2H2Oand1mmolSnCl4?5H2Oweredissolvedin70mLdeionizedwater.Meanwhile,0.1gCTAB(cetyltrimethylammoniumbromide)and15mmolNaOHweredissolvedinthesolutionabove.Afterwards,thesolutionwasstirredfor40min,transferredintoa100mLTeflon-linedautoclaveandheatedat180℃for24h.Afterreaction,thepowderwaswashedandcalcinedat550℃for2htoobtainZn2SnO4octahedral.ToprepareCaFe2O4nanorods,1mmolCaCl2and2mmolFeCl3weredissolvedintoamixedsolutionofethanol(30mL)anddeionizedwater(10mL)understirringatroomtemperaturefor30min.Themixedsolutionwastransferredintoa50mLautoclave,heatedat180℃for12h.Afterreaction,thepowderwaswashedanddriedat80℃for8htoobtainCaFe2O4nanorods.ToprepareCaFe2O4/Zn2SnO4composites,2mmolZn(CH3COO)2?2H2Oand2mmolZn(CH3COO)2?2H2Oweredissolvedin70mLdeionizedwater.Meanwhile,0.1gCTAB(cetyltrimethylammoniumbromide)and15mmolNaOHweredissolvedinthesolution.Theas-preparedCaFe2O4sampleswereaddedintotheZn2SnO4reactionmixture,andthemixturewasstirredfor40min,transferredintoa100mLTeflon-linedautoclaveandheatedat180℃for24h.Afterreaction,thepowderwaswashedandcalcinedat550℃for2htoobtainCaFe2O4/Zn2SnO4composites.AtdifferentadditionamountsofCaFe2O4(i.e.,0.0063,0.0125gand0.0188g),theCaFe2O4/Zn2SnO4compositeswithdifferentmolefractionsof2%,4%and6%wereobtained,andmarkedas2%CaFe2O4/Zn2SnO4,4%CaFe2O4/Zn2SnO4and6%CaFe2O4/Zn2SnO4,respectively.ResultsanddiscussionTheX-raydiffractionpatternsshowthatZn2SnO4isaperovskitestructureandCaFe2O4isaclinopyritestructure.TheXRDpatternofCaFe2O4/Zn2SnO4compositesisclosetothatofZn2SnO4,andnoCaFe2O4diffractionpeaksappear,probablyduetothesmallamountofCaFe2O4.FortheFouriertransforminfraredspectraofCaFe2O4/Zn2SnO4composites,Ca-O,Fe-OandSn-Obondsappearat565,478cm-1and574cm-1inthesecomposites,demonstratingthatCaFe2O4/Zn2SnO4compositesaresynthesized.Inaddition,comparedwithCaFe2O4andZn2SnO4,thecharacteristicabsorptionpeaksofCaFe2O4/Zn2SnO4compositesallshiftslightlytotherightregion,confirmingtheexistenceofinterfacialcontactbetweenCaFe2O4andZn2SnO4.Forthescanningelectronmicroscopyandtransmissionelectronmicroscopyimages,Zn2SnO4isanoctahedralstructurewithauniformsizeofapproximately350nm,whileCaFe2O4hasananorodstructurewithalengthofapproximately180nm.FortheX-rayphotoelectronspectra,elementsZn,Sn,Fe,CaandOcoexistinCaFe2O4/Zn2SnO4composites,andZn2SnO4incorporatedwithCaFe2O4increasestheoxygenvacancydefectsbytheGausspeakdivisionmethod.ComparedwithpureCaFe2O4,Zn2SnO4andotherCaFe2O4/Zn2SnO4sensors,4%CaFe2O4/Zn2SnO4sensorexhibitsaprominentgassensingperformancetoethanol(i.e.,afavorableselectivitytoethanol,alowdetectionlimitof0.07μmol/L,fastresponse/recoverytimeof21s/63s,long-termstability,andhighgasresponse(96)toward40μmol/Lethanol).Thesuperiorethanolgassensingperformanceof4%CaFe2O4/Zn2SnO4isattributedtotheformationofCaFe2O4-Zn2SnO4p-nheterojunctions,thehighcontentofoxygenvacancydefects,andtheincreasedsurfaceelectrondensity.Therefore,CaFe2O4-Zn2SnO4p-nheterojunctioncompositehasagreatpotentialapplicationfordetectingethanolgas.ConclusionsZn2SnO4octahedral,CaFe2O4nanorodsandCaFe2O4/Zn2SnO4compositeswerepreparedbyahydrothermalmethod.4%CaFe2O4/Zn2SnO4basedsensorexhibitedthemaximumgasresponseof96μmol/Lto40μmol/Lethanolat400℃,whichwas2.6timeshigherthanthatofZn2SnO4and34timeshigherthanthatofCaFe2O4.Moreover,4%CaFe2O4/Zn2SnO4basedsensoralsoachievedalong-termstability,anexcellenthumidityresistance,fastresponse-recoverytime(21s/63s)andalowtheoreticaldetectionlimitof0.07μmol/Lforethanol.Theenhancedgassensingpropertiesof4%CaFe2O4/Zn2SnO4couldbeattributedtothefollowingfactors,i.e.,CaFe2O4coupledwithZn2SnO4decreasedtheelectron-holerecombinationefficiency,andincreasedthesurfaceelectrondensity;andtheformationofp-nheterojunctionsbetweenCaFe2O4andZn2SnO4increasedthicknessofDebyeelectronlayer,resultinginadrasticresistancechange.TheappropriateamountofCaFe2O4coupledwithZn2SnO4couldbeapromisingstrategytoenhancethesensingperformanceofethanol,havinggreatpotentialsinmanufacturinghighresponseandlowdetectionlimitofethanolsensors.
作者：郭威威 雒润东 张合静 李晓丹 韩利雄 Author：GUOWeiwei LUORundong ZHANGHejing LIXiaodan HANLixiong
作者单位：重庆工商大学环境与资源学院,催化与环境新材料重庆市重点实验室,重庆400067重庆先进光电显示技术研究院,重庆401346重庆国际复合材料股份有限公司,重庆400000
刊名：硅酸盐学报 ISTICEIPKU
Journal：JournaloftheChineseCeramicSociety
年，卷(期)：2024, 52(7)
分类号：TP212TN379
关键词：锡酸锌 铁酸钙 异质结 乙醇 气体传感器
Keywords：zincstannate calciumferrite heterojunction ethanol gassensor
机标分类号：TN304.92TP212.2O643.36
在线出版日期：2024年7月24日
基金项目：国家自然科学基金，重庆市教委科学技术研究项目，重庆市研究生科研创新项目，重庆市研究生联合培养基地科研创新项目基于CaFe2O4/Zn2SnO4异质结型气体传感器的构建及其乙醇气敏性能优化机制[
期刊论文] 硅酸盐学报--2024, 52(7)郭威威 雒润东 张合静 李晓丹 韩利雄乙醇是一种无色、易燃易爆、挥发性强的有机化合物,属于挥发性有机污染物(VOCs).在人体健康和酒驾检测中是一种重要的标志性气体.采用水热法制备了CaFe2O4、Zn2SnO4和CaFe2O4/Zn2SnO4复合材料,并对晶体结构、元素组成、形...参考文献和引证文献
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