1、SECOND EDITIONELECTROCHEMICALMETHODSFundamentals andApplicationsAllen J.BardLarry R.FaulknerDepartment of Chemistry and BiochemistryUniversity of Texas at AustinJOHN WILEY&SONS,INC.New Yorke Chichester WeinheimBrisbane e Singapore e TorontoAcquisitions Editor David HarrisSenior Production Editor Eli
2、zabeth SwainSenior Marketing Manager Charity RobeyIllustration Editor Eugene AielloThis book was set in 10/12 Times Roman by University Graphics and printed and bound byHamilton.The cover was printed by Phoenix.This book is printed on acid-free paper,o oCopyright 2001 John Wiley&Sons,Inc.All rights
3、reserved.No part of this publication may be reproduced,stored in a retrieval system or transmitted in any form or by anymeans,electronic,mechanical,photocopying,recording,scanning or otherwise,except as permitted underSections 107 or 108 of the 1976 United States Copyright Act,without either the pri
4、or written permission of thePublisher,or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center,222 Rosewood Drive,Danvers,MA 01923,(978)750-8400,fax(978)750-4470.Requests to the Publisher forpermission should be addressed to the Permissions Department,John W
5、iley&Sons,Inc.,605 Third Avenue,New York,NY 10158-0012,(212)850-6011,fax(212)850-6008,E-Mail:PERMREQWILEY.COM.To order books or for customer service,call 1(800)-CALL-WILEY(225-5945).Library of Congress Cataloging in Publication Data:Bard,Allen J.Electrochemical methods:fundamentals and applications/
6、Allen J.Bard,Larry R.Faulkner.2nd ed.p.cm.Includes index.ISBN 0-471-04372-9(cloth:alk.paper)1.Electrochemistry.I.Faulkner,Larry R.,1944-II.Title.QD553.B37 2000541.37_dc2100-038210Printed in the United States of America10 9 8 7 6 5 4 3 2 1PREFACEIn the twenty years since the appearance of our first e
7、dition,the fields of electrochemistryand electroanalytical chemistry have evolved substantially.An improved understandingof phenomena,the further development of experimental tools already known in 1980,andthe introduction of new methods have all been important to that evolution.In the prefaceto the
8、1980 edition,we indicated that the focus of electrochemical research seemed likelyto shift from the development of methods toward their application in studies of chemicalbehavior.By and large,history has justified that view.There have also been importantchanges in practice,and our 1980 survey of met
9、hodology has become dated.In this newedition,we have sought to update the book in a way that will extend its value as a generalintroduction to electrochemical methods.We have maintained the philosophy and approach of the original edition,which is toprovide comprehensive coverage of fundamentals for
10、electrochemical methods now inwidespread use.This volume is intended as a textbook and includes numerous problemsand chemical examples.Illustrations have been employed to clarify presentations,and thestyle is pedagogical throughout.The book can be used in formal courses at the senior un-dergraduate
11、and beginning graduate levels,but we have also tried to write in a way thatenables self-study by interested individuals.A knowledge of basic physical chemistry isassumed,but the discussions generally begin at an elementary level and develop upward.We have sought to make the volume self-contained by
12、developing almost all ideas of anyimportance to our subject from very basic principles of chemistry and physics.Becausewe stress foundations and limits of application,the book continues to emphasize themathematical theory underlying methodology;however the key ideas are discussed con-sistently apart
13、 from the mathematical basis.Specialized mathematical background is cov-ered as needed.The problems following each chapter have been devised as teaching tools.They often extend concepts introduced in the text or show how experimental data are re-duced to fundamental results.The cited literature is e
14、xtensive,but mainly includes onlyseminal papers and reviews.It is impossible to cover the huge body of primary literaturein this field,so we have made no attempt in that direction.Our approach is first to give an overview of electrode processes(Chapter 1),show-ing the way in which the fundamental co
15、mponents of the subject come together in anelectrochemical experiment.Then there are individual discussions of thermodynamicsand potential,electron-transfer kinetics,and mass transfer(Chapters 2-4).Conceptsfrom these basic areas are integrated together in treatments of the various methods(Chapters 5
16、-11).The effects of homogeneous kinetics are treated separately in a waythat provides a comparative view of the responses of different methods(Chapter 12).Next are discussions of interfacial structure,adsorption,and modified electrodes(Chap-ters 13 and 14);then there is a taste of electrochemical in
17、strumentation(Chapter 15),which is followed by an extensive introduction to experiments in which electrochemistryis coupled with other tools(Chapters 16-18).Appendix A teaches the mathematicalbackground;Appendix provides an introduction to digital simulation;and Appendix contains tables of useful da
18、ta.vi PrefaceThis structure is generally that of the 1980 edition,but important additions have beenmade to cover new topics or subjects that have evolved extensively.Among them are ap-plications of ultramicroelectrodes,phenomena at well-defined surfaces,modified elec-trodes,modern electron-transfer
19、theory,scanning probe methods,LCEC,impedancespectrometry,modern forms of pulse voltammetry,and various aspects of spectroelectro-chemistry.Chapter 5 in the first edition(Controlled Potential Microelectrode Tech-niquesPotential Step Methods)has been divided into the new Chapter 5(BasicPotential Step
20、Methods)and the new Chapter 7(Polarography and Pulse Voltamme-try).Chapter 12 in the original edition(Double Layer Structure and Adsorbed Interme-diates in Electrode Processes)has become two chapters in the new edition:Chapter 12(Double-Layer Structure and Adsorption)and Chapter 13(Electroactive Lay
21、ers andModified Electrodes).Whereas the original edition covered in a single chapter experi-ments in which other characterization methods are coupled to electrochemical systems(Chapter 14,Spectrometric and Photochemical Experiments),this edition features awholly new chapter on Scanning Probe Techniq
22、ues(Chapter 16),plus separate chapterson Spectroelectrochemistry and Other Coupled Characterization Methods(Chapter 17)and Photoelectrochemistry and Electrogenerated Chemiluminescence(Chapter 18).Theremaining chapters and appendices of the new edition directly correspond with counter-parts in the ol
23、d,although in most there are quite significant revisions.The mathematical notation is uniform throughout the book and there is minimal du-plication of symbols.The List of Major Symbols and the List of Abbreviations offer defi-nitions,units,and section references.Usually we have adhered to the recomm
24、endations ofthe IUPAC Commission on Electrochemistry R.Parsons et al.,Pure Appl.hem.,37,503(1974).Exceptions have been made where customary usage or clarity of notationseemed compelling.Of necessity,compromises have been made between depth,breadth of coverage,andreasonable size.Classical topics in e
25、lectrochemistry,including many aspects of thermo-dynamics of cells,conductance,and potentiometry are not covered here.Similarly,wehave not been able to accommodate discussions of many techniques that are useful but notwidely practiced.The details of laboratory procedures,such as the design of cells,
26、theconstruction of electrodes,and the purification of materials,are beyond our scope.In thisedition,we have deleted some topics and have shortened the treatment of others.Often,we have achieved these changes by making reference to the corresponding passages in thefirst edition,so that interested rea
27、ders can still gain access to a deleted or attenuated topic.As with the first edition,we owe thanks to many others who have helped with thisproject.We are especially grateful to Rose McCord and Susan Faulkner for their consci-entious assistance with myriad details of preparation and production.Valua
28、ble commentshave been provided by S.Amemiya,F.C.Anson,D.A.Buttry,R.M.Crooks,P.He,W.R.Heineman,R.A.Marcus,A.C.Michael,R.W.Murray,A.J.Nozik,R.A.Oster-young,J.-M.Saveant,W.Schmickler,M.P.Soriaga,M.J.Weaver,H.S.White,R.M.Wightman,and C.G.Zoski.We thank them and our many other colleagues throughoutthe el
29、ectrochemical community,who have taught us patiently over the years.Yet again,we also thank our families for affording us the time and freedom required to undertakesuch a large project.Allen/.BardLarry R.FaulknerCONTENTSMAJOR SYMBOLS ixSTANDARD ABBREVIATIONS xix1 INTRODUCTION AND OVERVIEW OF ELECTRO
30、DE PROCESSES 12 POTENTIALS AND THERMODYNAMICS OF CELLS 443 KINETICS OF ELECTRODE REACTIONS 874 MASS TRANSFER BY MIGRATION AND DIFFUSION 1375 BASIC POTENTIAL STEP METHODS 1566 POTENTIAL SWEEP METHODS 2267 POLAROGRAPHY AND PULSE VOLTAMMETRY 2618 CONTROLLED-CURRENT TECHNIQUES 3059 METHODS INVOLVING FOR
31、CED CONVECTIONHYDRODYNAMICMETHODS 33110 TECHNIQUES BASED ON CONCEPTS OF IMPEDANCE 36811 BULK ELECTROLYSIS METHODS 41712 ELECTRODE REACTIONS WITH COUPLED HOMOGENEOUS CHEMICALREACTIONS 47113 DOUBLE-LAYER STRUCTURE AND ADSORPTION 53414 ELECTROACTIVE LAYERS AND MODIFIED ELECTRODES 58015 ELECTROCHEMICAL
32、INSTRUMENTATION 63216 SCANNING PROBE TECHNIQUES 65917 SPECTROELECTROCHEMISTRY AND OTHER COUPLED CHARACTERIZATIONMETHODS 68018 PHOTOELECTROCHEMISTRY AND ELECTROGENERATEDCHEMILUMINESCENCE 736APPENDICESA MATHEMATICAL METHODS 769 DIGITAL SIMULATIONS OF ELECTROCHEMICAL PROBLEMS 785 REFERENCE TABLES 808IN
33、DEX 814MAJOR SYMBOLSListed below are symbols used in several chapters or in large portions of a chapter.Sym-bols similar to some of these may have different local meanings.In most cases,the usagefollows the recommendations of the IUPAC Commission on Electrochemistry R.Par-sons et al.,Pure Appl.Chem.
34、,37,503(1974).;however there are exceptions.A bar over a concentration or a current ej*.,Co(x,s)indicates the Laplace trans-form of the variable.The exception is when/indicates an average current in polaro-graphy.STANDARD SUBSCRIPTSaDdanodic(a)cathodic(b)chargingdiskdiffusiondleqf/double layerequili
35、brium(a)forward(b)faradaiclimiting0PRrpertaining to species 0 in +ne Rpeak(a)pertaining to species R in +ne R(b)ringreverseROMAN SYMBOLSSymbol MeaningUsual UnitsSectionReferencesCBcdct(a)area(b)cross-sectional area of a porouselectrode(c)frequency factor in a rate expression(d)open-loop gain of an a
36、mplifierabsorbance(a)internal area of a porous electrode(b)tip radius in SECMactivity of substance j in a phase aaFv/RTcapacitanceseries equivalent capacitance of a celldifferential capacitance of the doublelayerintegral capacitance of the double layerconcentration of species;bulk concentration of s
37、pecies;concentration of species;at distance xcmcm2depends on ordernonenonecm2nones1mol/cm2FFF,F/cm2F,F/cm2M,mol/cm3M,mol/cm3M,mol/cm31.3.211.6.23.1.215.1.117.1.111.6.216.4.12.1.56.3.113.5.31.2.2,10.1.210.41.2.2,13.2.213.2.21.4.2,4.4.31.4Major SymbolsSymbolCjCx=0)Cj(x,t)Cj(O,f)Cj(y=0)CscDj(A,E)DMsd*E
38、AEE%EAEEE0EAEacEbEdcMeaningconcentration of species j at theelectrode surfaceconcentration of species at distance xat time tconcentration of species at theelectrode surface at time tconcentration of species at distance away from rotating electrodesurface concentration of species at arotating electro
39、despace charge capacitancepseudocapacityspeed of light in vacuodiffusion coefficient for electrons withinthe film at a modified electrodediffusion coefficient of species concentration density of states for species model diffusion coefficient in simulationdiffusion coefficient for the primaryreactant
40、 within the film at a modifiedelectrodedistance of the tip from the substrate inSECMdensity of phase(a)potential of an electrode versus areference(b)emf of a reaction(c)amplitude of an ac voltage(a)pulse height in DPV(b)step height in tast or staircasevoltammetry(c)amplitude(1/2 p-p)of ac excitation
41、in ac voltammetryelectron energyelectric field strength vectorelectric field strengthvoltage or potential phasor(a)standard potential of an electrode ora couple(b)standard emf of a half-reactiondifference in standard potentials fortwo coupleselectron energy corresponding to thestandard potential of
42、a coupleformal potential of an electrodeactivation energy of a reactionac component of potentialbase potential in NPV and RPVdc component of potentialUsual UnitsM,mol/cm3M,mol/cm3M,mol/cm3M,mol/cm3M,mol/cm3F/cmFcm/scm/scm2/scm3eV!nonecm2/s/xm,nmg/cm3VVVmVmVmVeVV/cmV/cmVVVVeVVkJ/molmVVVSectionReferen
43、ces1.4.24.44.4.39.3.39.3.418.2.210.1.317.1.214.4.21.4.1,4.43.6.3B.1.3.B.1.814.4.216.4.11.1,2.12.110.1.27.3.47.3.110.5.12.2.5,3.6.32.2.12.2.110.1.22.1.42.1.46.63.6.32.1.63.1.210.1.17.3.2,7.3.310.1.1SymbolEFEmEgE;EmEPAPEp/2papcZ*EI21eee0%)erfc(x)Ff/(E)fUk)GAGGGMeaningequilibrium potential of an electr
44、odeFermi levelflat-band potentialbandgap of a semiconductorinitial potentialjunction potentialmembrane potentialpeak potential(a)|p a-p c|inCV(b)pulse height in SWVpotential where/=/p/2 in LSVanodic peak potentialcathodic peak potentialstaircase step height in SWVpotential of zero chargeswitching po
45、tential for cyclic voltammetryquarter-wave potential inchronopotentiometry(a)measured or expected half-wavepotential in voltammetry(b)in derivations,the reversiblehalf-wave potential,Eo+(RT/nF)n(DR/D0)l/2potential where i/i=1/4potential where/d=3/4(a)electronic charge(b)voltage in an electric circui
46、tinput voltageoutput voltagevoltage across the input terminals of anamplifiererror function of xerror function complement of xthe Faraday constant;charge on onemole of electrons(a)F/RT(b)frequency of rotation(c)frequency of a sinusoidal oscillation(d)SWV frequency(e)fraction titratedFermi functionfr
47、actional concentration of species/inboxy after iteration in a simulationGibbs free energyGibbs free energy change in a chemicalprocesselectrochemical free energystandard Gibbs free energyUsual UnitsVeVVeVVmVmVVVmVVVVmVVVVVVVVVVV/xVnonenoneV1r/ss-1s-1nonenonenonekJ,kJ/molkJ,kJ/molkJ,kJ/molkJ,kJ/molMa
48、jor Symbols xiSectionReferences1.3.2,3.4.12.2.5,3.6.318.2.218.2.26.2.12.3.42.46.2.26.57.3.56.2.26.56.57.3.513.2.26.58.3.11.4.2,5.4,5.55.45.4.15.4.110.1.1,15.115.215.1.115.1.1A.3A.39.310.1.27.3.511.5.23.6.3B.1.32.2.42.1.2,2.1.32.2.43.1.2xii Major SymbolsSymbol MeaningUsual UnitskJ,kJ/molkJ/molkJ/molc
49、m/s2J-cm2/mol2kJ,kJ/mols-l/2kJ,kJ/molkJ,kJ/molkJ/molJ-scmAC/s1/2AA-s1/2/(mg2/3-mM)SectionReferences2.1.2,2.1.33.1.22.3.613.5.22.1.25.5.12.1.22.1.23.1.27.1.410.1.26.7.110.1.27.1.3AG!jtransfer,jHMiA#/(0/7/8i/(0)*Od)maxstandard Gibbs free energy change in achemical processstandard Gibbs free energy of
50、activationstandard free energy of transfer forspecies j from phase a into phase/3(a)gravitational acceleration(b)interaction parameter in adsorptionisotherms(a)enthalpyenthalpy change in a chemical processstandard enthalpy change in a chemicalprocessstandard enthalpy of activationPlanck constantcorr