Helmholtz内层(IHP,innerHelmholtzplane)和Helmholtz外层(OHP，outerHelmholtzplane)图4.2电流–电势方程：(电化学反应的基本方程)i0=nFAk0Ci=nFAk0{COx(0,t)exp[-nf(E-E0')]-CRd(0,t)exp[(1-)nf(E-E0')]}PartIIElectrochemicalMethodsandTechniques1.Controlled–PotentialTechniques恒电势（位）仪potentiostat图1.2(a)WaveformforastepexperimentinwhichspeciesOiselectroactiveatE1,butisreducedatadiffusion-limitedrateatE2.(b)Concentrationprofilesforvarioustimesintotheexperiment.(c)Currentflowvs.time.Cottrellequation（1902）:图1.3Doublepotentialstepchronoamperometry.(a)Typicalwaveform.(b)Currentresponse.1.2.Chronopotentiometry(计时电势法)Figure1.7Differenttypesofcontrolled-Currenttechniques.(a)Constant-Currentchronopotentiometry.(b)ChronopotentiometrywithLinearlyincreasingcurrent.(c)CurrentreversalChronopotentiometry.(d)Cyclicchronopotentiometryi1/2/Co*=nFADo1/21/2/2=85.5nDo1/2AFigure1.8Figure1.10Reversiblesystem:Figure1.11IrreversibleandQuasi-reversibleSystems:StudyofAdsorptionProcessesFigure1.14StudyofReactionMechanisms1.3.2.Polarography（极谱法）图1.15ThedroppingmercuryelectrodeTheIlkovicequationforthelimitingdiffusioncurrent:(1.16)(1.17)Effectofchargingcurrent1.4PulseVoltammetry（脉冲伏安法）(G.C.BarkerandI.L.Jenkins,Analyst,1952,77,685)1.4.1常规脉冲伏安（极谱）法所产生的极谱图是一个稳态曲线，其极限电流可由修饰的Cottrell公式给出：(1.24)DPV能够更有效地扣除充电电流的影响；同时还可以降低背景电流的影响。1.4.3Square-WaveVoltammetry(方波伏安法)SWV最主要的优点是它的速度快！Figure1.211.5.ACVoltammetry（交流伏安法）卷积去卷积技术1.6.StrippingAnalysis（溶出分析）1.6.1AnodicStrippingVoltammetry(ASV，阳极溶出伏安法)(主要针对可以形成汞齐的金属离子)Foramercuryfilmelectrode,thepeakcurrentisgivenby1.6.2PotentiometricStrippingAnalysis(PSA，电势溶出分析)Advantage:TheuseofnondeaeratedsamplerepresentsanimportantAdvantageofPSA.1.6.3AdsorptiveStrippingVoltammetryandPotentiometry1.6.4CathodicStrippingVoltammetry（阴极溶出伏安法）1.7ACImpedance（交流阻抗法）1.7.1TypesofTechniques图1.27Schematicdiagramofapparatusforanacvoltammetricexperiment.1.7.2电化学系统的交流阻抗的含义如果扰动信号X为正弦波电流信号，那么响应信号Y为正弦波电势信号，则称G()为系统M的阻抗(impedance)，用Z表示。如果扰动信号X为正弦波电势信号，那么响应信号Y为正弦波电流信号，则称G()为系统M的导纳(admittance),