xps eng電子能譜是60年代末和70初才發(fā)展起來的一種研究表面新

PhotoelectronXPS:X-rayPhotoelectronAES:AugerElectronUPS:UltravioletPhotoelectronSpectroscopyXPS,alsoknownasESCA(ElectronSpectro-scopyforChemical ysis),isthemostwidelyusedsurface ysistechniquebecauseofitsrelativesimplicityinuseanddata一定量的電子，X射線或紫外中不同能級的電子激發(fā)成自由息，并具有特征能量，收集這Acertainamountofelectrons,X-sample,thanthesamplesurfaceelectronscanbeexcitedintothetheinformationofthesamplesenergy,collectingtheseexcitedWhatis–X-rayPhotoelectronspectroscopy,basedonthephotoelectriceffect,1,2wasdevelopedinthemid-1960’sbyKaiSiegbahnandhisresearchgroupattheUniversityofUppsala,1.H.Hertz,Ann.Physik31,9832.A.Einstein,Ann.Physik17,132(1905).1921NobelPrizein3.K.Siegbahn,et.al.,NovaActaRegiaeSoc.Sci.,Ser.IV,Vol.20NobelPrizeinPhysicsPrinciplesofXPSBasedonphotoelectriceffect收的光子的能量大于電子的結合能及樣品的功函數(shù)，該電子可以逃逸出品表面，跑到真空中，并且還具有一定的動能，這就是光電效應ThePhotoelectricIt'sbeendeterminedexperimentallythatwhenlightshinesonametalsurface,thesurfaceemitselectrons.Forexample,youcanstartacurrentinacircuitjustbyshiningalightonametal te.Whydoyouthinkthishappens? Ifawaveoflighthitanelectroninoneoftheatomsinthemetal,itmighttransferenoughenergytoknockthe 光電效具有足夠能量的入射光子（h）同樣品相互作用時， ThePhotoelectricCorelevelelectronsareejectedbytheX-rayradiationTheK.E.oftheemittedelectronsisdependenton:InstrumentworkElementbinding

KineticKE=hν-(EB+EB=ElectronBindingKE=ElectronKineticΦspec=SpectrometerWorkXPSIntensitiesofphotoelectronsversus析 移（Chemical化 現(xiàn)可以利用原子的靜電模型（tticl。內(nèi)電子主要感受到原子核的侖力，使電子在原子內(nèi)具合，同時內(nèi)層電子又受到外電子的 作用（推斥力ExampleofChemicalFunctionsofElementalidentificationandchemicalstateofRelativecompositionoftheconstituentsinthesurfaceregionValencebandElectron X-rayArionElectronicComputerVacuumUltrahighvacuumsystem<10-9Torr(<10-7DetectionofAvoidsurfaceXPSspectrallinesareidentifiedbythefromwhichtheelectronwasejected(1s,2s,2p,Forp,dandfpeaks,twopeaksare–Theseparationbetweenthetwopeaksarenamed

rbitalsplitting.Thevaluesofspinorbitalsplittingofacorelevelofanelementindifferentcompoundsarenearlythesame.–Thepeakarearatiosofacorelevelofanelementindifferentcompoundsarealsonearlythesame.層激發(fā)出來的分別計為2s,2p?,2p3/2光電子，以此類推M層和N層都有光電子產(chǎn)生。其中Ag3d3/2和Ag3d5/2光電子是Ag的兩個最強特征峰 XPSspectrumofaNiXPSinExceptHandHe,allotherelementshavecharacteristicXPSandAESpeaksThesepeakshardlyoverlappedoneChemicalshift→oxidationThus,XPScanbeusedtoidentifytheelementanditsoxidationstate X－射線光電子能譜在催化研究中的應組分鑒別（identificationof價態(tài)分(oxidation半定量分析 SensitivityNanocastedsynthesisofmesoporousperovskiteNanostructuredceria/bariumT10=400,T50=540,T90=690

Citrate

T10=335°CT50=470°CT90=550 a:MesoporousCr2O BindingRestructuringTransitionMetalOxideNanorodsfor100%SelectivityinReductionofNitricOxidewithCarbonMonoxideNanoLett.2013,13,CO+H2O=J.Am.Chem.Soc.2013,135,Ag-TiO2/KIT-6復合納米光 N2物理吸附、XPS、UV-VisDRS和TEM對系列催化劑進行表征，結果A-.圖3為各催化劑的Uv-VisDRS譜。負載Ag與未負載(4O0～6OOnm)出現(xiàn)強的吸收峰，這歸屬為單質(zhì)si，O和C五種元素存在。圖4是Ag3d，Ti2p的分析圖譜。如圖4(b)所示，兩樣品的XPS譜均在458.7和464.2eV左右出現(xiàn)兩個峰，它們對應于TiO2(Ti4+