TableofContents
Cover
AdvancesinElectrochemicalScienceandEngineering
TitlePage
Copyright
ListofContributors
SeriesEditorsPreface
Preface
Chapter1:PropertiesofCarbon:AnOverview
1.1OverviewofProperties
1.2DifferentFormsofCarbon
1.3Outlook
References
Chapter2:ElectrochemistryatHighlyOrientedPyrolyticGraphite(HOPG):Towarda
NewPerspective
2.1Introduction
2.2StructureandElectronicPropertiesofHOPG
2.3FormativeStudiesofHOPGElectrochemistry
2.4MicroscopicViewsofElectrochemistryatHOPG
2.5Conclusions
Acknowledgments
References
Chapter3:ElectrochemistryinOneDimension:ApplicationsofCarbonNanotubes
3.1CarbonNanotubes:GeneralConsiderations
3.2StructureandSynthesisofCNTs
3.3StructureofCNTsversusElectrochemicalProperties
3.4StrategiesforthePreparationofCarbonNanotube-BasedElectrodes
3.5ProspectiveWork
References
Chapter4:ElectrochemistryofGraphene

4.1OverviewofGrapheneProperties
4.2PreparationofGraphene
4.3CapacitanceofGrapheneElectrodes


4.4ElectronTransferKineticsatGrapheneElectrodes
4.5ConclusionandFutureDirections
References
Chapter5:TheUseofConductingDiamondinElectrochemistry
5.1Introduction
5.2ElectrodeGeometriesandArrangements
5.3EffectofSurfaceTerminationontheElectrochemicalResponseofBDD
5.4PolycrystallineVersusSingle-CrystalElectrochemistry
5.5ImpartingCatalyticActivityonBDD
5.6ChemicalFunctionalizationofBDDElectrodes
5.7ElectroanalyticalApplicationsofBDD
5.8Conclusions
Acknowledgments
References
Chapter6:ModificationofCarbonElectrodeSurface
6.1Introduction
6.2CovalentModification
6.3NoncovalentModification
6.4FutureDirections
Acknowledgments
References
Chapter7:CarbonMaterialsinLow–TemperaturePolymerElectrolyteMembraneFuel
Cells
7.1Introduction
7.2CarbonasSupportMaterialinFuelCellElectrocatalysts

7.3CarbonasCatalyticallyActiveComponentinFuelCells
7.4CarbonasStructure-FormingElementinPorousFuelCellElectrodes
7.5SummaryandOutlook
Acknowledgments
References
Chapter8:ElectrochemicalCapacitorsBasedonCarbonElectrodesinAqueous
Electrolytes
8.1Introduction
8.2FundamentalsonCarbon/CarbonElectricalDouble-LayerCapacitors


8.3CarbonsandElectrolytesforElectricalDouble-LayerCapacitors
8.4AttractiveElectrochemicalCapacitorsinAqueousSolutions
8.5ConclusionsandPerspectives
References
Chapter9:CarbonElectrodesinElectrochemicalTechnology
9.1Introduction
9.2CommentsontheCarbonsMetinElectrochemicalTechnology
9.3ManufactureofChemicals
9.4WaterandEffluentTreatment
9.5FlowBatteries
References
Chapter10:CarbonElectrodesinMolecularElectronics
10.1Introduction
10.2Fabrication
10.3NovelAllotropesofCarboninMolecularElectronics
10.4ChargeTransport
10.5ConclusionsandProspects
Acknowledgments
References

Chapter11:CarbonPasteElectrodes
11.1Introduction:CarbonPasteElectrodes–TheStateoftheArt
11.2CarbonPasteastheElectrodeMaterial
11.3ModifiedCarbonPasteElectrodes
11.4LatestAchievementsinElectroanalysiswithCMCPEsandCP-Biosensorsand
PerspectivesfortheFuture
References
Chapter12:Screen-PrintedCarbonElectrodes
12.1Introduction
12.2ConductivityofComposites
12.3CarbonPolymorphs
12.4OxygenFunctionalities
12.5ActivatedCarbons
12.6Binder–SolventCombinations
12.7PVDFProperties


12.8PVDFSolubility
12.9FlexibleSubstrates
12.10ScreenPrintingProcess
12.11ScreenPrintingMaterials
12.12InkFlow
12.13SubstrateWetting
12.14CommercialInkAdditives
12.15BinderPercentage
12.16MultilayeredElectrodes
12.17IRDrop
12.18ArealCapacitance
12.19EquivalentCircuit
References

Index
EndUserLicenseAgreement

ListofIllustrations
Chapter1:PropertiesofCarbon:AnOverview
Figure1.1Controlofthegrapheneplasmonresonancefrequencybyelectricalgating
andmicroribbonwidths.(a)AFM(atomicforcemicroscopy)imagesofgraphene
microribbonswithwidthsof1,2,and4µm.Colorbaroftheheightisshownonthe
right.(b)Fermienergy(EF)dependenceofthegrapheneplasmonfrequency (top
axisgivesrelateddependenceonchargedensity|n|1/2)ofribbonswiththreedifferent
widths.
Figure1.2Universallightabsorbanceandopticalconductivityofgraphene.(a)
SchematicofDirac-coneandinterbandopticaltransitionsingraphene.(b)Optical
absorbance(leftaxis)andopticalsheetconductivity(rightaxis)ofthreegraphene
samples.Thespectralrangeisfrom0.5to1.2eV.Theblackhorizontallineshowsthe
universalabsorbancevalueof2.293%perlayer,withthevariationwithin10%.(c)
TheopticalabsorbanceofgrapheneSample1andSample2overasmallerspectral
rangefrom0.25to0.8eV.
Figure1.3Ramanspectrumofgrapheneat0V(appliedbiasvoltage),excitedbya2.33
eVlaserradiation,inanelectrochemicalenvironment.Theasterisks(*)indicate
Ramanbandsoftheelectrolyte.
Figure1.4TheRamanscatteringprocessesoftheG,D,D′,andG′bandsofgraphene.
Figure1.5RamanspectraoftheG′bandofgraphenewithdifferentnumbersoflayers.


Theexcitationlaserwavelengthis514nm.
Figure1.6TheschematicillustrationofanexperimentalsetupofinsituRaman
spectroelectrochemistry.Thesample(12C/13Cbilayergrapheneinthissketch)isonthe
substratewithionicgating(lightgreycylinders),withtwoelectrodeprobesmadeof
AgandPt.ThebackgatingisthroughtheAumetalelectrode.Thesetupisplacedunder

theRamanspectrometertoachieveinsituRamanspectroscopy.
Figure1.7ThechangeofDbandwithelectrochemicaldoping.(a)Ramanspectraof
defectivegrapheneatdifferentFermienergies(EF),measuredunder633nmlaser
excitation.(b)ThenormalizedintensityoftheDbandasafunctionofFermilevel,or
chargecarrierconcentrationat514and633nmlaserexcitations.
Figure1.8InsituRamanspectroelectrochemistrydatafortheGandG′bandsof
grapheneexcitedby2.33eVlaserirradiation.TheheavyblacktraceisforV=0
appliedvoltage.
Figure1.9TheRamanspectraofbilayergraphenewiththetwolayersof:13C/12C,both
13C,andboth12C.Thegraphenewiththe13Cisotopehasred-shiftedGandG′peaks,
comparedto12Cgraphene.
Figure1.10Energybanddiagramanddensityofstates(DOS)ofacarbonnanotube.
The1DvanHovesingularitiesgiveahighDOSatwell-definedenergies.
Figure1.11(a)Acarbonnanotubedefinedbythechiralvector ,whichis
perpendiculartothenanotubeaxis.Here, isthechiralangle,and and arethe
unitvectorsofgraphene.(b)Possiblechiralvectors(n,m)ofcarbonnanotubes(see
text).Different(n,m)chiralitiesresultindifferentphysicalproperties,including
metallic(largedots)andsemiconducting(smalldots)nanotubes.
Figure1.12Threetypesofcarbonnanotubes:(a)armchair,(b)zigzag,and(c)chiral.
Thedefinitionofnanotubetypesisaccordingtotheorientationperpendiculartothe
nanotubeaxis.
Figure1.13(a)RamanspectraoftheGbandatseveralpotentialsappliedtoaSWCNT
bundle.(b,c)VariationoftheG+bandandG−bandfrequency,respectively,withthe
appliedpotentialforthreedifferentelectrolytesolutions.
Figure1.14Katauraplot[81–83],showingtherelationshipbetweenelectronic
transitionenergiesandtheSWCNTdiameters.Eachpointontheplotshowsan
opticallyallowedelectronictransitionenergyEii,whichistheenergyseparation
betweenvanHovesingularitiesintheconductionbandtothevalenceband.Crosses
representsemiconductingSWCNTs(labeled“S”)andcirclesrepresentmetallic
SWCNTs(labeled“M”).

Figure1.15VariationoftheC−Cbondlength(estimatedfromGbandvariation)with
electrochemicalchargetransfer(fc)inducedonthenanotubes.


Figure1.16GNRswithdifferentchiralorientations:zigzagandarmchair.
Figure1.17DevelopmentofedgestructuresingraphenenanoribbonsusingJoule
heatinginsideaTEM(transmissionelectronmicroscope).(a)Graphenenanoribbon
withzigzag–armchairedges.Theblackarrowsindicatethejunctionbetweenzigzagand
armchairedges.WiththeincreasedtimeofJouleheating(a–d),thezigzag-armchair
junctionpositionmoves.ThesketchesontheleftandrightoftheTEMimages(a–d)
indicatethegraphenenanoribbonstructuresbeforeandafterJouleheating,
respectively.Scalebarin(a):2nm.
Figure1.18Unzippingacarbonnanotubetoformagraphenenanoribbon.
Chapter2:ElectrochemistryatHighlyOrientedPyrolyticGraphite(HOPG):Towarda
NewPerspective
Figure2.1(a)SchematicsofthegraphitecrystalstructureofAB-stackedgraphiteand
thecorrespondingBrillouinzoneofbulkgraphite,togetherwiththelabelsforspecial
symmetrypoints.(b)SideviewsforBernal(ABA)stacking(left)andrhombohedral
(ABC)stacking(right).
Figure2.2AtomicresolutionSTMimagesofthesurfaceof(a)graphiteand(b)
graphene.Whilethegraphitesurfaceshowsatriangularstructure,thegraphenesurface
exhibitsthehoneycombstructurewithallsixatomsinthehexagonverticesvisible.
Figure2.3AFMimagesoffreshlycleavedHOPGsurfacesofdifferentgrades,
highlightingthesignificantdifferencesintopographicalstructure.Notethedifferences
inscalebars(lateralandheight).
Figure2.4(a)AFMimagesofBPPGand(b)Scanningelectronmicroscopyimagesof
EPPGatdifferentmagnifications.
Figure2.5RamanspectraacquiredondifferentHOPGgrades((a)AMand(b)SPI-3,
(c)BPPG,and(d)EPPG).
Figure2.6(a)Graphiteelectronicbandstructurealonghigh-symmetrylinesinthe

Brillouinzone.(b)ElectronicDOSofgraphite.(c)CurvesrepresentingtheDOSfor
pyrolyticgraphitedeterminedbyGerischerusingcapacitancemeasurements,compared
withthecurvesobtainedbytheSWMcCandJDmodelsforenergybandsneartheH-K
axis.
Figure2.7(a)STMimagesandSTSspectranearmonoatomicstepsofanHOPG
samplewithzigzagedge(top)andarmchairedge(bottom).Thecolorkeyonthe
spectraassignsthelateraldistanceofthetipfromthestepedge.(b)STSspectraof
grapheneandgraphite,showingafinitedifferentialconductanceattheneutralitypoint
forgraphite,consistentwiththefiniteDOS.
Figure2.8(a–d)SetofSTMimagesand(e–h)thecorrespondingSTSspectraof
HOPGsamplesthatexhibitMoirepatternsduetotheexistenceofatwistangle
(indicated)betweenthetopgraphenelayerandthelayerimmediatelyunderneath.


Figure2.9(a)(i)Ramanspectraoflaser-treatedHOPG(threepulses,50MWcm−2):
(A)offthelaserand(B)onthelaserspot.(a)(ii)CorrespondingCVsofFe(CN)63−/4−
(1MKCl),200mVs−1,onuntreated(uppercurve)andlaser-treated(lowercurve)
AM-gradeHOPG.(b)(i)Ramanspectraobtainedinairafterelectrochemically
pretreatingHOPGfor2minin0.1MKNO3solutionatdifferentpotentials,1565cm−1
peakisdioxygen:(A)1.6V;(B)1.85V;and(C)1.95VvsAg/AgCl.(b)(ii)
CorrespondingCVsofFe(CN)63−/4−(1MKCl),200mVs−1onAM-gradeHOPGafter
1.85Velectrochemicalpretreatment(ECP)(uppercurve)and1.95VECP(lower
curve).TheintensityoftheRamanDband,whichindicatesedgeanddefectsites,
yieldscomparableresultsforthetwosurfaceactivationprocedures,laseractivation
andECP,withECPgeneratingmoresurfaceoxidesthanlaseractivation.
Figure2.10Log–logplotofk0for“validated”AM-gradeHOPG(triangle)andlaseractivatedGC(circles)versuskexcforeightredoxcouples.Thehorizontallineindicates
theinstrumentallimitfork0determination,thedashedlineistheleast-squarefitforthe
HOPGdata,withslope=0.29andthesolidlineisfromtheproposedsimpleformof
therelationshipbetweenk0andkexcpredictedbyMarcustheory.Redoxsystemsare(1)
IrCl62−/3−,(2)Ru(NH3)63+/2+,(3)Co(phen)33+/2+,(4)methylviologen,(5)

Fe(phen)33+/2+,(6)Fe(CN)63−/4−,(7)Co(en)33+/2+,and(8)Ru(en)33+/2+,wherephenis
phenanthrolineandenisethylenediamine.
Figure2.11(a)Observedk0forFe(CN)63−/4−,calculatedfromCVmeasurementswith
theNicholsonmethod[155](insetshowssamedatawithalogarithmicordinate).(b)
Observedcapacitance,C0,forlaser-modifiedHOPG/aqueouselectrolytes,determined
fromsemi-integralvoltammetry[154],asafunctionoflaseractivationpowerdensity.
EachvoltammogramwastakenaftercleavageoftheHOPGsurfaceandthree9nslaser
pulsesinair.
Figure2.12(a)CVsrecordedatEPPGandbasalplaneHOPG.(b)Comparisonofthe
basalplaneHOPGvoltammogramswiththebestfittolineardiffusionCVsimulations
fortheoxidationof1mMFe(CN)64−(1MKCl)at1Vs−1.
Figure2.13CVforthereductionof1mMFe(CN)63−inaqueous0.1MKClsolutionat
ascanrateof75mVs−1:(a)ZYH-gradeHOPGelectrodeshowsahighlyirreversible
processand(b)ZYH-gradeHOPGelectrode,whichwashand-polishedtocreateedgeplanedefectsites,displaysbothareversibleandirreversibleprocess.(c)Relationship
ofΔEpfromCVstothepercentageofedgeplanecalculatedfromk0(withtwovalues
indicatedbyandΔ)and C0(▪).(d)Theindividualsecondtofifthharmonicpeak
currents(2–5ωt)fromACvoltammetry,withinsetshowingthecloserviewforthe
low-leveledge-planedefectregions.
Figure2.14CVsfor1mMFe(CN)63−/4−redoxcouple:(a)(i)oxidationin1MKCl


solutionat1.0Vs1onAM-gradeHOPG;(b)(i)oxidationin1MKClsolutionat1.0V
s1onSPI-1-gradeHOPG;and(c)(i)reductionin0.1MKClsolutionat75mVs1on
ZYH-gradeHOPG.(a)(ii)(c)(ii)CorrespondingAFMimagesoftheHOPGsurface
showingtypicalstep-edgedensitiesandcoveragefordifferentgradesofHOPG
samples.
Figure2.15(a)SchematicoftheSMCMsetup,showingtheone-electronoxidationof
FA+toFA2+atasubstrateelectrode.(b)Simulationsshowingtheinfluenceofkinetics
onSMCMCVs,forapipetteof2àmdiameterand7.5taperangle.Black:Nernstian
response.KineticcasesuseButlerVolmerequations(=0.5).Red:k0=0.1cms1,

Green:k0=0.01cms1,Blue:k0=0.001cms1(5mMredoxspecies,D=1ì105
cm2s1),istheoverpotential.(c)Experimental(black)andsimulated(Nernstian,
green;k0=0.01cms1,=0.5,red)CVsforapipetteof580nmdiameterwitha
solutionof2mMFA+(D=6ì106cm2s1).
Figure2.16(a)SchematicofthesimulationgeometrymodelforaNafion-coatedHOPG
surface(i),wherethenumbersareindicativeofthefilmsolutioninterface(1),
periodicboundariesfromwhichthesteparrayresponsecanbedetermined(2a,2b),
step-edgeplane(3),andbasalplane(4a,4b),respectively,andsimulatedconcentration
profilesforaNafion-Ru(bpy)32+(D=4.7ì1011cm2s1)filmatthehalf-wave
potentialfromaCVatascanrateof10mVs1(ii,iii)and1Vs1(iv,v).Thebasal
planewasassumedtobeinert(k0=0cms1;ii,iv)andactive(k0=1ì104cms1;
iii,v),withthestep-edgeactivityatk0=1ì104cms1.CVsrecordedatascanrate
of0.5Vs1onanSPI-1-gradeHOPGsurface,withadepositedthinNafionfilm
incorporating(b)Ru(bpy)32+and(c)Ru(NH3)63+,wheretheexperimentaldataare
showninblack,togetherwithsimulationswithbasalplanekineticseitherreversible
(red),inert(k0=0cms1,green),oractivewitharateconstantofk0=1ì104cms1
forRu(bpy)32+andk0=4.5ì105cms1forRu(NH3)63+(blue).
Figure2.17(a)SchematicoftheSECCMsetupandanscanningelectronmicroscopy
imageofatypicaltipemployed.(b)SECCMmapsfortheelectro-reductionof2mM
Ru(NH3)63+onZYA-gradeHOPG,showing(i)topography,(ii)ACcomponentofthe
conductancecurrent,(iii)surfaceelectroactivity,and(iv)ahistogramofallthe
electroactivity(redoxcurrent)pixelswithrespecttotheaverageactivity.(c)SECCM
surfaceelectroactivitymap(left)for1mMRu(NH3)63+reductionatAM-gradeHOPG,
withbothsurfacecurrent(green)andbarrelcurrent(blue)shownforatypicalline
acrossseveralsteps.(d)Surfaceelectroactivitymapfortheoxidationof2mM
Fe(CN)64(i),withtheaveragecurrentofeachlineintheimageshownin(ii).(e)
Normalizedlinearsweepvoltammogramsfortheoxidationof2mMFe(CN)64on
freshHOPG(black)andagedHOPGafter1hexposureinair(blue),withascanrate
of100mVs1.

Figure2.18(a)SchematicforfeedbackmodeofSECM.SECMsteady-statenormalized
currentdistanceapproachcurveswithagolddiscultramicroelectrode(UME)tip
(radius6àm)forFe(CN)64reductiontoward(b)HOPGand(c)glassycarbon,where
iisthecurrentandi()isthebulkcurrent.Thenormalizeddistanceistheabsolutetip
substratedistancedividedbythetipradius.
Figure2.19(a)Topographicaland(b)currentfeaturesonthesurfaceofHOPG
obtainedfromSECMAFM,withthecorrespondingcross-sectionalprofile(c)and(d)
alongthelinemarkedin(a)and(b),respectively.(e)Verticaldeflectionand(f)current
responseoftheupperareaof(a)and(b),andthenumbersindicatedaredifferent
supportpotentials,changingfromthewhiteline.(g)SimulationofSECMwitha
conicalelectrode,showingthecurrentprofilesacrossstep1in(a).Theexperimental
response(redline),thecurrentresponsewitha100timesenhancedreactionrateatthe
stepedge(blueline)andwithoutenhancedreactionrate(greenline).Notethesmall
changeinabsolutecurrentonthey-coordinate.
Figure2.20CVsfortheoxidationof1mMFe(CN)64in0.1MKClsolution,at0.1Vs
1,afterafreshlycleavedHOPG(SPI-1)surfacewasleft(a)incontactwithsolution
or(b)inair,aftercleavagefor0min(black),1h(red),and3h(green),and(c)after
leavingasampleinairfor24haftercleavage.
Figure2.21ConductiveAFMimages(5ì5àm)ofanHOPG(SPI-1)surfaceshowing
the(i)heightand(ii)conductivity(a)immediatelyaftercleavageand(b)24hafter
cleavage.TheconductiveAFMiVcurvesshownwererecordedontheterrace
locationsmarkedin(a)(ii)and(b)(ii).
Figure2.22(a)SECCMlinearsweepvoltammogramoftheelectro-oxidationof100
MDA(0.15Mphosphatebufferedsalinecontaining150mMNaCl(pH7.2)).Maps
of(b)surfaceactivity,(c)DCconductancecurrent,and(d)ACcomponentofthe
conductancecurrentobtainedwithSECCMsetup,togetherwith(e)anAFMimagein
thesamearea.
Figure2.23MacroscopicCVsfortheoxidationof1mMDA(a)(i),(b)(i)and1mM
EP(a)(ii),(b)(ii)onfreshlycleavedsurfacesofZYA-andSPI-3-gradeHOPG,ata

scanrateof0.1Vs1.
Figure2.24(a)SchematicoftheFSCVSECCMsetupwhere10sequentialCVscans
werecarriedoutineachofaseriesofspotsonanHOPGsurface,withholdtimesof
50ms,100ms,250ms,0.5s,1s,and5sbetweeneachCV.(b)FSCVsforthe
adsorptionof1MAQDSin0.05MHClO4solution,recordedat250msintervals
(holdtime)withascanrateof100Vs1,atAM-gradeHOPG.(c)Thefractional
coverageofAQDSandcorrespondingchargeindifferentpartsofanAM-gradeHOPG
surfaceasafunctionoftime,withrespecttothedifferentholdtimes.Solidlineisthe
simulatedbehaviorfordiffusion-controlledadsorption.(d)TypicalAFMimage(ex
situ)foranadsorptionspotonanAM-gradeHOPGsurfacetakenafterabout10s,


alongwitha3ì3àmhigherresolutionimage,withtheapproximatedropletfootprint
outlinedinwhite.(e)Percentageofstepedgesfoundwithinsixadsorptionspots,
whereFSCVmeasurementsweremade(atdifferenttotaladsorptiontime)andthe
observedfractionalcoverageofelectroactiveAQDS.
Figure2.25(a)SchematicshowingthemodificationofanHOPGsurfacewithan
electrogenerateddiazoniumradical.(b)AFMimageofthedepositionarrayonHOPG.
CVsof0.1mMdiazoniumin50mMH2SO4atthesurfaceof(c)AM-gradeand(d)
SPI-3-gradeHOPGatascanrateof0.2Vs1.
Chapter3:ElectrochemistryinOneDimension:ApplicationsofCarbonNanotubes
Figure3.1(a)Schematicrepresentationoftheroll-upvectoroverthegraphenesurface,
whichdefinesthedifferentCNTstructures.(b)SWCNTarmchair,zigzag,andchiral.
Figure3.2(a)TEMmicrographofas-synthesizedSWCNT.(b)TEMmicrographofa
samplecontainingbothMWCNTandbCNT.(twomagnificationsaredisplayedatright
andleftpanels,respectively).
Figure3.3Cyclicvoltammogramsin1mM
over(a)covalentlyalignedand
(b)drop-coatedSWCNT-modifiedAu/cysteamineelectrode.Supportingelectrolyte:
0.05MphosphatebuffersolutionpH7.0and0.05MKClsolution.

Figure3.4(a)SchematicrepresentationoftheprocedureforpreparingtheCNT
electrodeswithtipexposed(CNT-T)orsidewall(CNT-S)accessibletoelectrolyte.
CVsof2.0mMH2O2(b,c),and2.0mMascorbicacid(d,e)recordedinphosphate
buffersolutionpH6.5attheCNT-S(uppercurvesinbandd),O-CNT-S(lowercurves
inbandd),CNT-T(uppercurvesincande),andO-CNT-Telectrodes(lowercurves
inc,e).ThedottedcurveswererecordedatthecorrespondingCNTelectrodesinthe
absenceoftheelectrochemicalprobemolecules.Scanrate:0.100Vs1.
Figure3.5Valuesofchargetransferresistance(Rct)obtainedbyfittingwithan
equivalentcircuitoftheimpedancespectraperformedin
forseveral
electrodes(fromlefttoright):EPPG,bCNT,SWCNT,MWCNTwithdiameterequalto
30,50,and140nm,graphiteandBPPG.Theinsetshowsvaluesatalowerresistance
scale.
Figure3.6SEMmicrographsofglassycarbondisksmodifiedwithdifferent
dispersionsofMWCNT:(a)1.00mgml1MWCNTin1.00mgml1GOxsolution
preparedin50:50(v/v)ethanol/water;(b)1.00mgml10MWCNTin1.00mgml1
PEIsolutionpreparedin50:50(v/v)ethanol/water;(c)1.00mgml1bCNTin100
ppmdsDNAsolutionpreparedin50:50(v/v)ethanol/water(inset:bCNTindsDNA
solutionpreparedinwater);and(d)1.00mgml1MWCNTin0.25mgml1Polyhis
solutionpreparedin75:25(v/v)ethanol/acetatebuffersolutionpH5.00(inset:
MWCNTin2.00mgml1Polyhis).
Figure3.7SECMsurfaceplotimagesof(a)GCE/MWCNT-H2O,(b)GCE/MWCNT-


DMF,(c)GCE/MWCNT-CHI,and(d)GCE/MWCNT-Nafmodifiedwith1.0mgml1
ofCNTdispersion.Experimentalconditions:5.0ì104MFcOHsolutionin0.050M
phosphatebufferpH7.40.Imageparameters:1àms1tipscan,Etip=0.500V,Esubstrate
=0.000V.
Chapter4:ElectrochemistryofGraphene
Figure4.1Overviewfortheproductionmethodsofgraphene[19].

Figure4.2AschematictoshowthepreparationoftheMEgraphenesamplesand
transferprocess[22].
Figure4.3ShowingtheexperimentalsetupusedbyLiuetal.[34]forthe
electrochemicalexfoliationofgraphite.
Figure4.4SchematicofCVD-growngrapheneonNiandCusubstrates[54].
Figure4.5Capacitancepotentialcurvesforthebasalplaneofstress-annealedgraphite
forarangeofconcentrations(0.9,101,102,103,104,and105Mfromtopto
bottom)inNaF(pH=6)[69].
Figure4.6Schematicoftheelectrodefabrication[3].
Figure4.7Acomparisonforthe(a)calculatedand(b)measuredcapacitanceof
monolayergraphenewheneitheroneortwosidesareexposedto4MH2SO4
electrolytesolution.
Figure4.8Cintversuspotentialplotsforelectrodespreparedwithonetofivelayersof
grapheneina6Mpotassiumhydroxideaqueouselectrolyte[88].
Figure4.9Effectofn-dopingoncapacitanceofgraphenewithvariousconcentrations
using6Mpotassiumhydroxideaqueouselectrolyte.
Figure4.10(a)Shapeofthevoltammetryforradialandlineardiffusion.(b)Schematic
diagramshowingthedevelopmentofthediffusionlayerwithincreasingtime(orcharge
passed),thatis,from(i)to(iii).
Figure4.11Simulateddependenceofthevoltammetricshape(dimensionlesscurrentvs
potential)onthedomainsizeofaheterogeneoussurface.Thek0oftheslowand
fastkineticsdomainswere1ì104cms1and1ì102cms1,respectively.
Figure4.12(a)ComparisonofCVsobtainedforopen-edgegraphenenanofibers(oSGNFs)andfolded-edgegraphenenanofibers(f-SGNFs).SchematicandTEM
micrographsofthe(b)o-SGNFand(c)f-SGNF.
Figure4.13(a)Microelectrode-shapedvoltammogramsobtainedonthegraphenedecoratedSAMAuelectrode.(b)Schematicofthemicroelectrodefabrication.
Figure4.14(a)SchematicofthemonolayerCVDgraphene(grey,labelled)with
induceddefects(lightgreyzonewithdashedoutline)depositedonaSi/SiO2substrate


(black).Panels(b)and(c)showSECMmapsofthegraphenewithinduceddefectsand

thesameareapassivatedusingo-phenylenediamineelectropolymerization,
respectively.
Figure4.15(a)SchematicoftheSECCMsetup,(b)voltammetryobtainedona
graphenesurface.Scannedareawithvariedflakethicknessesofdifferentlightcontrast
andelectrochemicalactivityisshownas(c)opticalmicrographand(d)corresponding
SECCMmap.Panels(e)and(f)showcorrelationbetweenthefeedbackcurrentor
HETrateandthelightcontrast(numberofgraphenelayers),respectively.
Figure4.16Schematicoftheedge-plane(a)andbasalplane(b)monolayergraphene
device,fabricatedusingpoly(methylmethacrylate)(PMMA)andepoxyresin(ER).
Figure4.17(a)SchematicoftheMEgraphenemonolayerelectrodepreparation.(b)
Microelectrodevoltammetricresponseobtainedonmono-,bi-,andmultilayer
grapheneflakes,normalizedtotheflakeradius.
Figure4.18(a)Photographand(b)theschematicofthemicromanipulatorsetupused
fordepositionofliquidmicrodropletsonthesurfaceofgrapheneelectrodes.
Figure4.19(a,b)Scanningelectronmicrographs,(c)transmissionelectronmicrograph,
and(d)electrondiffractionpatternofthe“3Dgraphene”catalyst.Panels(e)and(f)
showthephotovoltaicandvoltammetriccharacterizationofthematerialpreparedusing
threedifferentreactiontimes.
Chapter5:TheUseofConductingDiamondinElectrochemistry
Figure5.1(a)Roomtemperatureresistivityasafunctionofborondoping
concentration.(Takenwithpermissionfrom[14]).(b)p-typelow-dopedBDDat(i)
absolute0K,nocarriersarethermallyexcitedfromthevalencebandtoacceptor
states;thediamondisaninsulatorandtheFermilevel,EF,ismid-gapand(ii)nonzero
temperature;thenumberoffreecarriersinthevalencebandwilldependonthe
concentrationandtheionizationenergyoftheboronacceptors(EA)andthe
temperature,yieldinganactivatedelectricalresistivityintermediatebetweenthatofan
insulatorandthatofametal;theFermilevelwillmovedownwardtowardthetopof
thevalenceband.(iii)p-typeheavilydopedBDD( 1020Batomscm−3),whenthe
impuritiesarecloseenough,quantumoverlappingoftheirwavefunctionsresultsin
delocalizationleadingtometallicbehavioratzerotemperaturewithaFermilevel

pinnedinsidetheimpurityband;themetal–insulatortransitiontakesplace.(iv)Very
highdopinglevels>1020Batomscm−3;screeningoftheimpuritiesmodifiesthe
acceptoractivationenergyandtheintrinsicbandgapenergywillreduce.
Figure5.2(a)Schematicshowinggrainstructureofathickpolycrystallinediamond
film.Differentialboronuptakeindifferentgrainsindicatedbydarkandlightregions.
(b)Processingofsampletoremovegrowthandnucleationsurfaces.(c)Resultant
sampleforinvestigation.Notethecomplexinterconnectionofgrainswithdifferent
dopantdensities.


Figure5.3Differentexperimentalarrangementsusedbyresearcherswhenworking
withBDDelectrodes.(a)Forthin-filmBDDstillattachedtothegrowthsubstratean
glasselectrochemicalcellcanbeused.(AdaptedfromRef.[35].)(i)CuorAlmetal
current-collectingplate;(ii)thediamondfilmelectrode;(iii)theVitonO-ringseal;(iv)
theinputfornitrogenpurgegas;(v)carbonrodorPtcounterelectrode;and(vi)
referenceelectrode.(b)PreparationofBDDfree-standingelectrodes.(Adaptedfrom
Ref.[36]withpermission.)(i)LasermicromachiningisusedtocuttherequiredBDD
electrodegeometryfromaBDDfree-standingwafer;(ii)hereacylinderisrevealed.
Theelectrodeisohmicallycontacted,sealedinglass,andpolishedflattorevealthe
electrodestructureintheleftof(iii).Alsoshownareconventionalpolymer-sealedPt,
Au,andglassycarbonelectrodes.(c)Scanningelectronmicroscopy(SEM)imagesofa
nanoelectrodearray.(AdaptedfromRef.[37].)(i)Overviewofthedesignwith
distancesof10µmbetweenneighboringelectrodeswithhexagonalorder(indicatedin
red)and(ii)recesseddiamondelectrode,theinsulatingdiamondlayerisclearly
visible.(d)SchematicviewsofatopcontactedBDDmultiplyaddressableband
electrodedevice,wheretheBDDbandelectrodeslieoninsulatingsiliconoxide.
Figure5.4All-diamondcoplanarmicro-andmacroelectrodes.(a)Multiple
microelectrodearrayformedfrommachiningpillarstructuresinfree-standingBDD,
overgrowingwithinsulatingdiamond,andthenpolishingflattorevealacoplanar
structure.SEMsideonviewofcross-sectionedmicroelectrodearray.(TakenfromRef.

[50]withpermission.)(b)AtomicForceMicroscopy(AFM)topographyimageofone
oftheelectrodesinthearray;thelocationoftheBDDmicrodiskultramicroelectrodeis
clearlyvisible.(TakenfromRef.[28]withpermission.)(c)Top:multipleindividually
addressablemicrobandarrayelectrodes,ofwidth200µm,formedbygrowingBDD
intotrenchstructuresininsulatingdiamond.TheNDCbackcontacttoeachelectrodeis
visible.Bottom:topcontactedBDDring-diskelectrodeformedusingthesame
procedure.Thediameterofthediskelectrodeis3mm.
Figure5.5(a)SEMofanas-grownMCBDDelectrode.(TakenfromRef.[62]with
permission.);(b)Left:SEMoflappedsurfaceofMCBDD;Right:corresponding
Ramanmapofthesamearea.Forboth,zonesofdarkerintensitycorrespondtomore
heavilyboron-dopedregionsofthesurface.(TakenfromRef.[18]withpermission.)
(c)SEMofthin-filmBDDNCand(d)SEMofthin-filmBDDUNC.
Figure5.6CVsrecordedin0.1MKNO3atascanrateof0.1Vs−1forhighlydoped
NDC-freefree-standing,microcrystallineBDD(top),NDC-containingfree-standing,
microcrystallineBDD(seconddown),glassycarbon(thirddown),andplatinum
(bottom).TheCVshavebeenplottedondifferentscalesandverticallyoffsetfor
clarity.
Figure5.7Cyclicvoltammetriccurvesforalowerquality,NDC-containingthinfilm
diamondfilmelectrodein0.1MH2SO4beforeandafteracidwashingand
rehydrogenation.Scanrate,0.1Vs−1.


Figure5.8(a)Ramanspectraofthe[100]facetofB-dopedindividualdiamond
crystalsrecordedwithasingle-mode514.5nmlineofanAr-ionlaseratlowpower
(about5mW).“B/C”referstoB/Cinthegasphase.(TakenfromRef.[73]with
permission.)AtlowB,aNDCGpeakisevidentat 1500cm−1;astheBconcentration
increases,thediamondphononpeakbecomesmoreasymmetricandreducesinsize.(b)
VisibleRamanspectrumforaboron-dopedNCdiamondthinfilmatlaserwavelength
=532nmandpower=50mW.Integrationtime=5s.
Figure5.9(a)SchematicrepresentationshowingthepositionoftheRu(NH3)63+and

FcTMA+coupleswithrespecttovalence(EVB)andconduction(ECB)bandsforboth
O-andH-terminatedsemiconductingBDD.H-termination(O-termination)isknownto
induceanegative(positive)electronaffinity,withavalueof−1.3eV(+1.7eV)
measuredinvacuum[84].ThepresenceofwatermoleculesscreeningtheC−H(C−O)
surfacedipoleisexpectedtoreducethevalueoftheelectronaffinity(χ)towardlessnegative(positive)values.Wehavechosenavalueofapproximatelyχ=−1.0eVandχ
=+1.3eVforH-andO-terminatedsurfaces,respectively.Intheelectrolyteregion,the
leveloftheAg/AgClreferenceelectrode(Eref)isshown,andallappliedvoltagesare
referredtoitsenergy.(b)CVsperformedwitha1mmdiameterdiskelectrodeof
freestandingpolishedmicrocrystallineBDDelectrodeofdopantdensity
(blackline),
(redline),mid-1019(blueline),
(pinkline),and
−1
(greenline)atascanrateof0.1Vs for(i)theoxidationof1mMFcTMA+
and(ii)thereductionof1mMRu(NH3)63+in0.1MKNO3.(TakenfromRef.[17]with
permission.)Theresultingpeak-to-peak(ΔEp)separationsaregivenforthedifferently
dopedelectrodesinthetwodifferentredoxmediatorsolutions.
Figure5.10Schematicillustrationof(a)outer-sphereand(b)inner-sphereredox
process.OHPistheouterHelmholtzplaneandIHPistheinnerHelmholtzplane.
Figure5.11(a)Schematicofthehydrogenateddiamondsurfaceincontactwithawater
layerasitformsinair.(b)Evolutionofbandbendingduringtheelectrontransfer
processattheinterfacebetweendiamondandthewaterlayer.VBM=valanceband
maximum,CBM=conductionbandmaximum,EF=Fermilevel,μe=chemical
potentialoftheliquidphase.
Figure5.12(a)ContactanglesforH-andO-terminatedBDD[102](b)XPSC1s
spectraofsemiconductingH-plasma-treatedBDD(i)beforeand(ii)after
electrochemicaloxidationat1.5Vfor10minin0.1MKH2PO4[108].
Figure5.13CVcurves.(a)H-terminatedlow-doped( 1018)BDDelectrodein10mM
Fe(CN)63−/4−with1MKCl,scanrate=25mVs−1.(b)O-terminatedlow-doped
( 1018)BDDelectrodein10mMFe(CN)63−/4−with1MKCl,scanrate=25mVs−1.

(c)O-terminatedhigh-doped( 1020)BDDelectrodein3mMFe(CN)63−/4−with1M
KCl,scanrate=20mVs−1.


Figure5.14(a)SchematicillustratingSECMSG-TCmode.Theheterogeneouslyactive
BDDelectrodeisbiasedatapotentialtoelectrolyzetheredoxcouple(OxtoRedor
RedtoOx).Thetipisbiasedatasuitablepotentialtoconverttheelectro-generated
speciesbacktoitsoriginalformatadiffusion-controlledrate.Variationsintipcurrent
reflectvariationsintheunderlyingETcapabilitiesofthesurface.Infeedback,thetipis
biasedtoelectrolyzetheredoxcoupleandthesubstrateleftunbiasedorbiasedtoturn
overtheelectro-generatedformoftheredoxcoupleatadiffusionlimitedrate.(b)
SECMSG-TCimageofpolishedfree-standingMCBDD,
,for
2+
3+
substrategenerationofRu(NH3)6 fromRu(NH3)6 ata25-µm-diameterimagingtip.
(TakenfromRef.[28]withpermission.)(c)SECMfeedbackimageofpolishedfreestandingMCBDD,
,recordedwitha2µmtipelectrodebiasedata
3+
potentialtoconvertRu(NH3)6 toRu(NH3)62+.(TakenwithpermissionfromRef.
[121].)(d)ScanningRamanimage(left)andintermittentcontactSG-TCSECMimage
(right)ofthesurfaceofpolishedfree-standingMCBDD,
,witha2µmtip
2+
+
electrode,biasedatapotentialtoconvertFcTMA toFcTMA .
Figure5.15(a)Boron-dopedfilmwithitsHPHTsubstratebeforecuttingandpolishing.
(b)Freestandingboron-dopeddiamondfilm.
Figure5.16SEMandAFMimagesofdifferentmetalNPsdepositedunderdifferent
conditionsonBDD.(a)SEMimagesofflower-like(left)andsphericalgoldNPs

electrodepositedonMCBDDbyvaryingtheelectrodepositionconditions.(Takenfrom
Ref.[143]withpermission.)(b)SEMofcitrate-cappedgoldNPsformedonas-grown
BDDbythelayer-by-layerassemblyprocedure.(TakenfromRef.[154]with
permission.)(c)SEMofplatinumnanoparticleselectrodepositedonBDD
microelectrodesaftertwodepositioncycles.(TakenfromRef.[149]withpermission.)
(d)AFMimageofnickelhydroxidenanoparticlesdepositedonfree-standingpolished
MCBDDbyelectrochemicallygeneratingOH−inthepresenceofNi2+.
Figure5.17CVresponsesof0.1MphosphatebuffersolutionpH4atascanrateof50
mVs−1intheabsenceandpresenceof1mMarsenic(III)at(a)BDDelectrode,(b)Irwireelectrode,and(c)Ir-BDDelectrode.
Figure5.18(a)Descriptionofthesuccessivediamondsurfacefunctionalizationsteps:
first,aminationwithrfplasma,thenaminolysiswith4-pentynoicacid,ynecoupling
usingathiolatedoligonucleotide.(ModifiedfromRef.[180]withpermission.)(b)
IllustrationofthemultistepfunctionalizationofBDDelectrodes:first,diazotization,
thenelectroreductionofthediazoniumsaltforelectrograftingofphenylazidemolecules
andfinallyclickcycloadditionbetweentheimmobilizedphenylazidemoleculesandssDNA(fluorescentlylabeled).
Chapter6:ModificationofCarbonElectrodeSurface
Scheme6.1Reductiveelectrograftingofaryldiazoniumonacarbonsurface.
Figure6.1CyclicvoltammogramsrecordedataGCelectrodewithoutDPPH(left)and


with1mMofDPPH(right)inasolutionofCH3CNcontaining0.1M
tetrabutylammoniumhexafluorophosphateand1mMof4-nitrobenzenediazoniumata
scanrateof50mVs−1.
Figure6.2Massversustimeresponseofacarboncoatedquartzcrystalmicrobalance
fortheelectrochemicalgraftingof4-nitrobenzenediazonium(1mM)atafixedpotential
of−0.5VversusAg/AgNO3.DataarefittedusingtheLangmuirmodel(solidlines).
Scheme6.2Reactiontoattachsilylgroupsattheparapositionofaryldiazonium.
Scheme6.3Modificationprocesstogetmonolayersurfacecoverageoncarbonusing
differentprotectinggroups.TMS,TES,TIPS,andTBAFrepresenttrimethylsilyl,
triethylsilyl,tri(isopropyl)silyl,andtetrabutylammoniumfluoride,respectively.

Figure6.3ComparisonofbiasstabilityofmolecularjunctionswithCuande-Castop
contacts.Cujunctionbreaksdownatapproximately−1.86V,duetoelectrochemical
oxidationofCu,whilee-Cisstableuptoabiasof3.5V.
Scheme6.4Oxidativeelectrograftingofamineoncarbonsurface.
Figure6.4CVsobtainedatGCinasolutionofethanolcontaining0.1MLiClO4and1
mM(a)butylamine,(b)N-methylbutylamine,(c)N-ethylbutylamine,(d)N,Ndimethylbutylamine,and(e)triethylamine.Thescanratewas10mVs−1.
Figure6.5XPSspectraintheN(1s)regionforGCelectrodemodifiedbycyclingthe
potentialoncebetween0.0and1.4VversusAg/AgClinethanolicsolutionsof1mM
(a)butylamine,(b)N-methylbutylamine,(c)N-ethylbutylamine,and(d)N,Ndimethylbutylamine.Scanratewas10mVs−1
Figure6.6CVsmeasuredatGC(a,c)andpyrolyzedphotoresistfilms(b,d).(a,b)First
scan(—)andsecondscan(---)(0.2Vs−1)withstirringbetweenscansinasolution
of5.2mM1-naphthylmethylcarboxylateand0.1Mtetrabutylammonium
tetrafluoroborateinacetonitrile.(c,d)Scansof3.1mM
inaqueous0.2M
KClatbare(---)and1-naphthylmethylcarboxylatemodified(—)surfaces.
Scheme6.5Mechanismofgraftingbyusingaredoxmediator.
Scheme6.6Oxidativeelectrograftingofalcoholoncarbonsurface.
Scheme6.7VarioussurfaceconstructionstrategiesoniodinatedPPF.Firstly,PPF
surfaceisiodinatedbyexposingittoiodineplasma.Iodinatedsurfacecanthenbe
reactedwithdifferentalkeneandalkynecompoundsinthepresenceofappropriatelight
(A,B,andC).Furthersurfacemodificationcanthenbeachievedvia“click”reaction
(B)orattachmentofnanoparticle(C).
Scheme6.8Modificationofgraphenewith(a)monoaryldiazoniumsalt,(b)
biaryldiazoniumsalt,and(c)bipyrene-terminatedmolecularwire.
Scheme6.9Reversibleinteractionofchargedpyrenederivativesongraphitesurface.


Scheme6.10Watercontactangle(a)andwaterabsorption(b)imagesofuntreatedand
CTAB-treatedcarbonfelts.
Scheme6.11ElectrodepositionofMWCNTsusingCTABsurfactant.(a),(b)and(c)

showthepossiblearrangementsofCTABonMWCNTs.
Chapter7:CarbonMaterialsinLow–TemperaturePolymerElectrolyteMembraneFuel
Cells
Figure7.1Schematicillustrationtocategorizethemostprominentcarbonmaterials.
Figure7.2Thethreecharacteristicsofcarbonblackdeterminingitsrichproperties:
particlesize,aggregatestructure,andsurfacechemistry.
Figure7.3TemplatingstrategyforobtainingCMK-3carbonfromSBA-15silica[10].
Figure7.4Imagesofthemostprominentcarbonaceoussupportmaterials:(a)graphite
and(b)Vulcancarbon.(TakenfromRef.[14].Copyright(2014),withpermissionfrom
ElsevierLimited).
Figure7.5ComparisonofRamanspectraofdifferentcarbonmaterials[16].
Figure7.6CK-edgeNEXAFSspectraofdifferentcarbonmaterials(J.Melke,
unpublishedresults).
Figure7.7Schematicillustrationofthethree-phaseboundaryinfuelcellelectrodes.
Figure7.8False-colorimageofanultrathinsectionofafuelcellelectrode;theinset
showsatypicalcarbonagglomerate.
Figure7.9(a)Current–voltagecharacteristicsofthethreemorphologicallydifferent
supportmaterialswiththelongfibersdisplayingthehighestpoweroutput.(b)The
chordlengthdistributionsforthelongandshortfibersarecompared.
Figure7.10Comparisonof3D-reconstructedvolumesof(a)anairbrushedelectrode
and(b)anLbL-preparedelectrode(b).[131](
Figure7.11Electronmicrographsofacrosssectionofamultilayerelectrode
composedofbilayersofPtonSb-dopedtinoxideandmultiwalledcarbonnanotubesin
differentmagnifications[147].
Figure7.12ElectrospunandcarbonizedPANfibersdecoratedwithPt(a;brightspots
attributedtoPtparticles)andanoverviewofthefinalfreestandingporouselectrode
structure(b).
Figure7.13(a)SchematicillustrationofaPickeringemulsionand(b)SEMpictureof
therespectivePt/SnO2shellaroundapolyaniline(PANI)coresample.
Figure7.14(a)Crosssectionthroughacatalyticlayerformedby“self-assembly”of

thePickeringemulsionand(b)thecorrespondingfuelcellpolarizationcurve.
Chapter8:ElectrochemicalCapacitorsBasedonCarbonElectrodesinAqueous


Electrolytes
Figure8.1Schematicrepresentationofthechargedstateofasymmetricelectrical
double-layercapacitorusingporouselectrodesanditssimplifiedequivalentcircuit.
Figure8.2Ragoneplotofvariouselectrochemicalenergystoragesystems.
Figure8.3Gravimetriccapacitanceversus(a)BETand(b)DFTspecificsurfacearea.
Figure8.4MolarproportionsofTEA+andBF4−calculatedfromtheNMRspectra,and
relativeamountofANversusthetotalamountofelectrolytespecies,afterpolarization
atvariouscellpotentialsfor30mininthe(a)positiveand(b)negativeelectrodesof
AC/ACelectrochemicalcapacitor.
Figure8.5VolumetriccapacitanceofmicroporouscarbonsinTEABF4/ANelectrolyte
vsaveragewidth(Lo)ofporesaccessibletoCCl4[57].
Figure8.6Nitrogenadsorption/desorptionisothermsobtainedat77K(a)and
quenchedsoliddensityfunctionaltheory(QSDFT)poresizedistribution(b)ofAC,
AC-PTFE,andAC-PVDFelectrodes.Fortheelectrodes,theamountofnitrogen
adsorbedisreferredtothemassofAC[60].
Figure8.7RagoneplotsofAC/ACcapacitorsin1moll−1Li2SO4and6moll−1KOH
aqueoussolutionswithcelloperatingpotentialwindows0–1.6and0–1.0V,
respectively.Valuescalculatedforthetotalmassofactivematerials.
Figure8.8Three-electrodecyclicvoltammograms(2mVs−1)showingthepotential
stabilitywindowofACin6moll−1KOH,1moll−1H2SO4,and0.5moll−1Na2SO4
[17].
Figure8.9Three-electrodecyclicvoltammogramsofACin2moll−1Li2SO4.The
variousloopsareobtainedbystepwiseshiftingofthenegativepotentiallimit.The
verticaldashedlineat−0.35VversusNHEcorrespondstothethermodynamic
potentialforwaterreduction.
Figure8.10VariationofpHvalueaftercathodiccharging(−500mAg−1for12h)of

ACelectrodesin0.5moll−1Na2SO4solutionswheretheinitialpHwasadjustedby
additionof1moll−1H2SO4or1moll−1NaOH.
Figure8.11Schemeoftheacceleratedagingprotocol(a)andmagnificationofthefifth
galvanostaticcycle(b).Thefifthdischargecycleofeachseriesisconsideredto
estimatethecapacitanceandESRvalues.
Figure8.12Effectoffloatingcellpotentialat24°Conthe(a)relativecapacitanceand
(b)relativeresistanceofanAC/ACcapacitorin1moll−1Li2SO4[98].
Figure8.13Poresizedistribution(PSD)ofafreshelectrode(fulldarkgrayline)and
ofagedpositive(dashedlightgreyline)andnegative(dottedlightgreyline)electrodes


after120hoffloatingat1.7Vin1moll−1Li2SO4.TheQuenchedSolidDensity
FunctionalTheory(QSDFT)wasusedtodeterminethePSD[98].
Figure8.14TPDonpristineACC(fulldarkgreyline)andonagedpositive(dashed
lightgreyline)andnegative(dottedlightgreyline)carbonelectrodesafter120hof
floatingat1.7Vin1moll−1Li2SO4:(a)masslossandCO2evolution;(b)massloss
andCOevolution;(c)deconvolutionofCO2;and(d)COpatterns(fulllightgreyline:
TPDexperimentaldata;dashedlines:individualpeaks;thickdashedline:sumofthe
individualpeaks).
Figure8.15NyquistplotsofAC/ACcapacitorsat0Vbeforeandafterfloatingat1.6V
for120hin(a)1moll−1Li2SO4and(b)1moll−1Li2SO4+0.1moll−1Na2MoO4
[106].
Figure8.16VoltammetrycharacteristicsofanAC/ACcellin1moll−1KIsolution:(a)
AC/ACcellwithSCEreferenceat5mVs−1;(b)two-electrodesystemat1,10,and
100mVs−1potentialscanrate.
Figure8.17Cyclicvoltammograms(at1mVs−1)oftwo-electrodecellsoperatingwith
activatedcarbonsAAC1orAAC2iniodide/vanadiumconjugatedredoxcouplesas
electrolytesolutions[112].
Chapter10:CarbonElectrodesinMolecularElectronics
Figure10.1Generalizedschematicofagenericmolecularjunction,consistingofa

molecule(canbeoneormany)placedbetweentwoconductors(examplesforeach
contactareforillustrativepurposes).Asshown,awidevarietyofmaterialscanbe
used,andthechoiceofmoleculesandcontactscanimpactthespecificelectronic
interactionsattheinterface–chemisorption(C−C,Si−SiOx)orphysisorption(π–π,S
−Au,etc.),whichcanexertacontrollinginfluenceonjunctionbehavior.Upon
applicationofvoltageacrossthejunction,currentflowsacrossthemolecularlayer.
However,thesystemshouldbetreatedaswhole,asthethicknessandelectronic
propertiesofthemoleculearenottheonlyfactorsthatwilldictateconductivity.
Figure10.2Schemeshowingchemicallymodifiedelectrodesthatareusedtostudy
variouselectrochemicalprocesses,includingelectrontransferratesacrossmolecules.
Figure10.3Variousstructuresofmolecularjunctionscommonlyusedinmolecular
electronics:(a)Crossjunctionformedbyperpendicularlyorientedbottomandtop
contactswithamolecularlayersandwichedbetweentheconductors.Typicaljunction
sizesrangefromseveralsquaremicronstoasquaremillimeter.(b)Anall-carbon
molecularjunctionformedusingpyrolyzedphotoresistfilm(PPF)(onSiO2support)as
abottomcontact,anevaporatedcarbon(eC)topcontact,andamolecularlayer
consistingofamultilayerofbiphenylgraftedusingdiazoniumchemistry.(c)Molecular
junctionmadebycontactingathiols-basedself-assembledmolecularlayeronAgwith
aliquid–metal(inthiscase,aeutecticalloyofGaandIn).((c)ReproducedfromRef.


[36].)(d)Amechanicallycontrolledbreakjunctionformedusingretractable
electrodescontrolledwithanSTM,wheremoleculesinsolutionbridgethegapto
resultinajunction[37].(e)Otherexperimentalgeometriesforstudyingelectronic
propertiesofsinglecarbonnanotubesoragraphenenanoribboncanbemadethrough
formingcontactswithlithographicmethods.
Figure10.4FabricationandmeasurementsofmolecularjunctionformedonPPFusing
diazoniumchemistry.(a)CyclicvoltammogrammeasuredataPPFelectrodefeaturing
anirreversiblereductionpeakatapproximately−0.8Vthatcorrespondstothe
reductionofdiazoniumionswithsubsequentformationofaC−CwithPPF.Growthof

themolecularlayerresultsintheincreasedblockingofelectrontransferfromthe
electrodeandgradualdecreaseofthepeakintensity(seealsoChapter6oncarbon
electrodemodification).(b)AFMimageofthemolecularlayerobtainedin(a),
showingthatfilmishomogeneous,andthatthethicknesscanbemeasuredusingAFM.
(c)Overlayofthecurrentdensity–voltagecharacteristics(semilogarithmicscale)of
eightjunctionsshowinggoodreproducibility.(d)Ramanspectra(measuredwitha514
nmprobethroughanopticallytransparentquartz/PPFsubstratemadebydilutingthe
photoresist)ofaQ/PPF/NAB/CujunctionwithandwithoutaCutopcontactshowing
nochangesinthestructureofanitroazobenzenemolecularlayer.(c)(Reprintedwith
permissionfromRef.[72].Copyright(2010)AmericanChemicalSociety).(d)
Figure10.5Biasandtemperaturestabilityofall-carbonMJs:(a)ComparisonofCu
ande-Castopcontacts,showingthattheuseofCuleadstobreakdownat
approximately−1.86V(duetoelectrochemicalreactionsofCu),whilee-Cshows
stabilityto±3.5V(withcurrentdensitiesupto 1500Acm−2),junctionarea:
).(b)OverlayofJ–VcurvesforPPF/NAB(4.1)/Auand
PPF/NAB(4.1)/eC(10)/Aujunctionsshowingthat10nmofe-Cpreventspenetrationof
Au.(c)J–VcurvesofPPF/NAB(4.5)/e-Cjunctionafterheatinginvacuum
for30minateachtemperature.(d)J–VcurvesofaPPF/NAB(4.5)/e-C
junctionbeforeandafter
cyclesat100°Cinlabambient(air)overthecourse
of 68h.(AdaptedwithpermissionfromRef.[82].)(e)J–VcurvesofaPPF/BrP(3)/eC/Aujunctionbeforeandaftertheapplicationof±0.8VDCbiasfor1–4hatroom
temperature.Insetsdisplaythesamedataplottedinasemilogscale.
Figure10.6(a,b)Electronicbandstructureofgrapheneshowingvalenceand
conductionbandstouchingattheDiracpointsandhavingalineardispersionrelation
aroundtheFermilevel.Comparisonof(c)zero-bandgapgraphene,(e)bandgapopenedgraphene,and(d)asemiconductor,suggestingthepossibleuseofzero-band
gapgrapheneasaconductorforMJsandwithabandgapasamolecularlayer.
Figure10.7Reversibleswitchingofconductanceinajunctionconsistingofgraphene
functionalizedwithspiropyran.Spiropyran,aphotochromicswitchattachedtoG
noncovalently,isabletochangestatesbetweentheringclosed(smalldipolemoment)
andringopen(largerdipolemoment)uponirradiationwithUVandvisiblelight.(a)

Changesintheelectronicconfigurationofspiropyranaretranslatedintochangesofthe


positionofDiracpointofgraphene(b),resultinginchangesintheappliedgatevoltage
(c)andconductance(d).
Figure10.8GraphenefunctioningastopandbottomelectrodesforMJs.(a)Similarly
toeC,thepresenceofgraphenebetweenmolecularlayerandAutopcontactprotects
thejunctionfromshortcircuitsbetweenelectrodes.(ReproducedfromRef.[106].)(b)
Usingdiazoniumchemistry,anazobenzenelayerwasgrowncovalentlyonagraphene
bottomcontact,whileatopgrapheneelectrodewascontactedphysically.The
mechanicalandopticalpropertiesofgrapheneelectrodesallowedtestingofelectronic
propertiesundermechanicalstress,and(c)photochemicalswitchingofazobenzene
betweencis-andtrans-isomersinducedbymulticycleswitching(d)oftheconductance
ofthejunction,whichwasreversible(e).
Figure10.9Formationofacarbonnanotubebyrollingupagraphenesheet.Depending
onthechiralvectoralongwhichthenanotubeisrolled,zigzag,armchair,andother
chiraloptionsarepossibleresultinginmetallicorsemiconductingCNTs.
Figure10.10ConstructionofFETswithindividual(aandb)andcollective(c)
nanotubes.(a)AFMimageofanFETcomposedofgoldsourceanddrainelectrodes
andanindividualcarbonnanotubeasachannel.Aheavilydopedwaferservedasa
backgateelectrode.Alternatively,anindividualtopgateelectrodemadeofTicanbe
employed(b).(a,b)(ReprintedwithpermissionfromRef.[132],Copyright(2002)
AmericanChemicalSociety.)(c)FETcomposedofanarrayofCNTs,withan
individualgateTi/Auelectrode,separatedwithanAl2O3/SiO2insulatinglayerand
Ti/Pdsourceanddrainelectrodes.
Figure10.11(a)Agapinananotubeiscreatedusinganoxygenplasmatoyieldaspace
offewnanometers,whichissuitablefortheformationofamolecularjunction.The
endsofcarbonnanotubesterminatedwithcarboxylicgroupsandservingasapointof
contactforfurtherfunctionalization.(b)OligoanilineplacedbetweenCNTcontacts
allows(c)reversibleswitchingoftheconductanceinthejunctionbychangesinthepH

duetoprotonation/deprotonation.
Figure10.12Agenericenergyleveldiagramofamolecularjunctionshowingthe
FermilevelofthecontactsoffsetfrommolecularHOMOandLUMOlevelstodefine
interfacialbarriers(here,abarriertoholetransportmediatedbytheHOMOisshown,
(φ)).Filledstatesintheconductorsareshaded.Aparallelsituationcanbedrawnfor
electrontunneling(usingtheLUMO).
Figure10.13(a)Attenuationplotforanelectrochemicalexperimentshownin(c).
Here,thellnoftheelectrochemicalrateconstantisplottedagainstthicknesstoyielda
slopeof0.22Å−1(or2.2nm−1).(b)Attentionplotforaseriesofaromaticmolecules
andanaliphaticspeciesbymolecularjunctionsofdifferentthicknessofeach(a
correspondingdiagramofthemolecularjunctionisillustratedin(d)).Seeoriginaltext
forstructuresandabbreviations.Here,thearomaticmoleculesgivesimilarbehavior
duetotheinteractionsbetweenthemolecularlayersandthesubstrate,asdiscussedin


thetext.(a)(ReprintedwithpermissionfromRef.[166].Copyright(1999)American
ChemicalSociety.)(b),(d)
Chapter11:CarbonPasteElectrodes
Figure11.1Typicalmicrostructuresoftworelatedgraphitepowdersandfourdifferent
carbonpastemixturesmadeofthesecarbons.Abbreviationsandsymbolsused:Cspe,
spectroscopic(orspectral)graphite;Cnat,refinednaturalgraphite;SO,siliconeoil;
TCP,tricresylphosphate;andIL,ionicliquid(BMImPF6);theindividualcarbonpastes
denotedaccordinglyabovetherespectiveimages(af).Experimentalconditions:
scanningelectronmicroscopy,magnification:1:1000(ae);scale:theactualsizeof
photoscorrespondsreallyto(25àmì35àm),1:500(f;s=50àm).Hitherto
unpublishedphotosfromauthors'archives,except(e)beingthealternateviewofan
imagepublishedin[37].Forotherspecificationanddetails,see[35,37,58,60].
Figure11.2Typicalmicrostructuresoftwonewformsofcarbonandfourcarbonpaste
mixtures,madeoftraditionaloilbindersandionicliquid.Abbreviationsandsymbols
used:Cspe,spectroscopicgraphitepowder;GC,glassycarbonpowder(Sigradurđ);

CNTs,carbonnanotubes(SW-type);MO,mineraloil;SO,siliconeoil(highly
viscoustype);andIL,ionicliquid(BMImPF6);theindividualcarbonpastemixtures
denotedaccordinglyabovetherespectiveimages(af).Experimentalconditions:
scanningelectronmicroscopy,magnification:1:1000,scaleasinFigure11.1.Hitherto
unpublishedphotosfromauthors'archives,except(a)beingthealternateviewofan
imagepublishedin[37].Forotherspecificationanddetails,see[35,37,5860].
Figure11.3Typicalfeaturesandbehavioroftraditionalornewcarbonpastesandthe
respectiveelectrodesincurrentflowmeasurements.(ad)Cyclicvoltammetryof
[Fe(CN)6]3/4in0.1MKCl,c(Fe)=5mM,lighterline,GCE(a,b)orGC-IL(c,d),
hithertounpublishedrecords;(e)AdsorptivestrippingvoltammetryofNiIIatthelow
partsperbillionlevelin0.1Mammoniabuffercontaining10MDMG(dimethyl
glyoxime)+HgII.Legend:curve(1)blank,(2)c(NiII)=5ppb,and(3)c(NiII)=10
ppb.Note:symbolO2denotesthereductiveresponseofoxygenentrappedinthepaste;
anouttakefrom[84];(f)Cathodicreductionofiodineathigherconcentrations
accumulatedin0.1MHClviaion-pairingandextraction.Legend:curve(1)blank,(2)
c(I)=0.01mM,and(3)c(I)=0.1mM;anouttakefrom[85].Abbreviationsand
symbolsused:C,spectralornaturalgraphitepowder;MO,mineraloil;SO,silicone
oil;TCP,tricresylphosphate;MF-,mercuryfilm;CNTPE,carbonnanotubepaste
electrode(SW-CNTs/SOtype);andCILE,carbonionicliquidelectrode
(Cnat/BMImPF6type).
Figure11.4Threeexamplesoftypicalapplicationsofchemically(ac)and
biologically(d)modifiedcarbonpasteelectrodes.(a,b)CalibrationsofPtIVandIrIIIat
themicromolarconcentrationlevelataCPEmodifiedinsituwithquaternary
ammoniumsalt.Legend:(a)baseline,(25)1,3,6,and9MPtIV;(b)(1)baseline,


(2–5)3,6,9,and12μMIrIIIexperimentalconditions:DPCSV;0.1Macetatebuffer+
0.1MKCl+1×10−5Mcetyl-tributylammoniumbromide(CTAB,pH4.5);
accumulationpotentialandtime:+0.9Vversus30s;stripping:from+0.9to−0.3V;
scanrateandpulseheight:10mVs−1;ΔE=−25mV.

Chapter12:Screen-PrintedCarbonElectrodes
Figure12.1Thescreenprintingprocess.
Figure12.2Meshandmaskgeometry.
Figure12.3Thebasicelementsofamultilayeredelectrode.
Figure12.4AscanningelectronmicroscopeimageofacrosssectionofascreenprintedporouscarbonelectrodehavingalowIRdrop.
Figure12.5Theequivalentcircuitofaporouscarbonelectrode.Itconsistsofasingle
verticalladdernetworkinserieswithanRCparallelnetwork.Theladdernetwork
modelstheresponseofporesinthebodyoftheelectrode,whereasthesolitaryRC
parallelnetworkmodelstheresponseoftheelectrolytesolution.(Inmanycases,the
capacitanceoftheelectrolytesolutionisbetterrepresentedasaconstant-phase
element.)

ListofTables
Chapter1:PropertiesofCarbon:AnOverview
Table1.1PhysicalpropertiesofHOPGat300K[47].
Chapter2:ElectrochemistryatHighlyOrientedPyrolyticGraphite(HOPG):Towarda
NewPerspective
Table2.1SummaryofsomekeypropertiesofdifferentgradesofHOPG
Chapter3:ElectrochemistryinOneDimension:ApplicationsofCarbonNanotubes
Table3.1MaincovalentfunctionalizationstrategiesforthemodificationofCNTswith
generalapplicationsinelectrochemistry
Table3.2Voltammetricparametersobtainedfromthecyclicvoltammogramsfor1.0×
10−3MAA
Table3.3NoncovalentfunctionalizationofCNTs:comparisonofdifferenttypesof
dispersingagentsandtheirgeneralapplicationsinelectrochemistry
Chapter5:TheUseofConductingDiamondinElectrochemistry
Table5.1Physicalpropertiesofdiamond[11,12].
Table5.2ListofcommercialcompaniessellingBDDelectrodes.
Table5.3NonexhaustiveTableofΔEpvaluesrecordedforsimpleredoxspeciesby

differentauthorsusingdifferentlypreparedBDDelectrodes.
Table5.4NonexhaustivelistofdifferentmetalNPsdepositedonBDDelectrodesfor
theelectrocatalyticdetectionofarangeofdifferentanalytes.
Chapter7:CarbonMaterialsinLow–TemperaturePolymerElectrolyteMembraneFuel
Cells
Table7.1Overviewofcharacterizationmethodsappliedtounravelthegeometricand
electronicstructuresofdifferentcarbons
Table7.2OverviewofvariousRamanbandsandtheirinterpretation
Table7.3Listofrequirementswhichagoodsupportmaterialhastofulfilland
exemplarydataforVulcanXC-72
Table7.4Overviewofprominentcarbonblackmaterialsappliedinfuelcellresearch
Chapter9:CarbonElectrodesinElectrochemicalTechnology
Table9.1Typicalconditionsforthemanufactureofmetalsbymoltensaltelectrolysis
Table9.2CurrentefficiencyfortheformationofozoneasafunctionofHBF4
concentrationforcellswithglassycarbonanodesandairGDEcathodes
Table9.3Theelectro-generationofstrongoxidantsatboron-doped,diamond-coated
anodes
Chapter10:CarbonElectrodesinMolecularElectronics
Table10.1Thickness,voltage,andtemperaturedependenceforvariouscharge
transportmechanismsrelevantinmolecularelectronics
Chapter11:CarbonPasteElectrodes
Table11.1Surveyof(unmodified)carbonpastesandthecorrespondingcarbonpaste
electrodes
Table11.2Commonmodifiersforcarbonpasteelectrodeswithtypicalexamples.
Table11.3Modifyingagentsforcarbonpastebiosensorswithtypicalexamples.
Chapter12:Screen-PrintedCarbonElectrodes
Table12.1Halogen-free,high-boilingsolventsforPVDF