光电化学课件研究进展

WenjunLuo* 俊

MyKeyLaboratoryofFlexibleElectronics(KLOFE)InstituteofAdvancedMaterials(IAM),NationalJiangsuSynergisticInnovationCenterforAdvancedMaterials(SICAM)NanjingTechUniversity(NanjingTech),Nanjing211816,China:

N.S.LewisNature414589SolarSolarconversionandstorageisonestepinaPECThefirstpaperonaPECcellforsolarwaterA.FujishimaandK.Honda,Nature238,37-38,Asinglephotoelectrodeforwatersplittingwithouta

Ap-ntandemPEC

EFH+.

SolarSolartohydrogenefficiency55PhotonPhotonflux(a

VB

PSI

n-photoanodep-Eg/e=1.23V+Vb(0.4V)+a(0.4V)+c(0.1V)+iRMurphyetal.Int.J.HydrogenEnergyMurphyetal.Int.J.HydrogenEnergy31,1999

-ntandemPECcellisthemostpromisingsystemwithhigh-efficiencyandlowcost

BiVO4和SuitablebandgapandHighabsorption3Highcarrier5.Low4.5.Low

270nmNaTaO3量子效A.Kudo,J.Am.Chem.Soc.125,3082,CBCBKudo,J.Am.Chem.Soc.121,11459,GaN-ZnO固溶体的量子效率和可见光分解水出氢K.Domen,Nature440,295,第一个具有可见光分解纯水制氢的氧氮化

Nat.Mater.2009,8,

LiuetalJ.Am.Chem.Soc.2012,134,G.Liuetal,Angew.Chem.2013,125,

Powderede-EF (1)SeparatedH2andEasierHigherutilizationrateofAhalfPECNatureMaterials,10,434,电电催化剂Mo3S4使p‐Si光阴极出氢开启电势降低Naturematerials12,158,NatureMaterials,10,456,电流电流Cu2O光阴极在AM1.5下具有最大的PECperformanceofaFe2TiO5AtotalPECaGaInP2photocathode+1GaAsaGaInP2photocathode+1GaAs高高效分解水(>10%),但光稳定性差,成本Naturephotonics6,824,Krol,NatureCommun.4,2195aWO3photoanode+1

aBiVO4photoanode+1SiaFe2O3photoanode+1DSSC

4photoanode+2Si

EnergyEnviron.Sci.4,4046Adv.Funct.Mater.22,3066Angew.Chem.Int.Ed.52,11016EnergyEnviron.Sci.6,347

EnergyEnviron.Sci.7,752Adv.EnergyMater.

Prof.

Prof.

DecreasingDecreasingReducing3.Suppressingback

Electronicstructuresandbandpositionsofsomevisible-light-responsephotoanodes2.1.1AnefficientBiVO4photoanodebydecreasing Bi(NO3)Bi(NO3)ionfor

Effectofions on

ClearMODClear

PhotocurrentPhotocurrent Driedat150oCWenjunLuoetal.EnergyEnviron.Sci.,2011,4,

PureTi4+NbOnlyMo6+,W6+canOnlyMo6+,W6+canenhancethephotocurrentof

PureSr2+Zn2+In3+La3+Ions inBiIncreasediffusiondistanceofphotogeneratedelectronsby

Effectof+6ions onCr6+impurityPhotocurrent/Photocurrent/mA22210

increasingdiffusiondistanceofincreasingdiffusiondistanceofphotogenerated,CarrierconcentrationincreasesafterMo

51/C51/C2(1010

Cr6+isdeepenergywhileMo6+orW6+isshallowZongyanZhao,WenjunLuoetal.Phys.Lett.A,374,2010,Differencebetweenshallowanddeeplevel

2.1.2.Decreasediffusiondistanceofphotogeneratedbymorphology

Donor

PhotocurrentPhotocurrent

ShallowenergylevelisbetterthandeepenergylevelPorousShallowenergylevelisbetterthandeepenergylevelXinZhao,WenjunLuo*etal.,Adv.EnergyMater. Whyaporousphotoelectrode

VisualizedevidenceforshorterholediffusiondistanceinaporousstructureCurrentCurrent

AbsorbanceAbsorbance 0

200

200IPCEIPCE

350400450500550600650ChargeSeperationChargeSeperation0380400420440460480500

380400420440460480500

200 200IPCEηsepIPCEηsepHigherlightHigherinterfacechargetransfer?200200500500Potential(V)vs.Amechanismforhigherperformanceinaporous

TorealizeefficientsolarseawatersplittingoutdoorsforfirstSolar(themostrenewableSolar(themostrenewable＋Seawater(themostabundantnaturalresource)D D

WenjunLuoetal.EnergyEnviron.Sci.4,4046ZhigangZou,WenjunLuoetal.ChinesePatent, 2010,

11 Ld=20

Optimizationparticlesize<2Ld(40 ofsolarhydrogenproductionfromnaturalseawateroutdoors

RecordsolarphotocurrentofBiVO4photoanodesfromdifferentgroupsintheworldMyChoietal.,Chem.Soc.Rev.2.2.AnefficientTa3N5photoanodebyremoving

PreparationofTa3N5PhotonPhotonflux/mWcm

SolarSolartohydrogenefficiency/AM

OxidationandnitridationofTafoilsathigh

Why

550-

50

MingxueLi,WenjunLuo*etal.Angew.Chem.Int.Ed.2013,52,11016(insidebackcoverpaper) 4.8 umsolarenergyconversionMurphyetal.Int.J.HydrogenEnergy31,1999PhotocurrentafterthermalorPhotocurrentafterthermalormechanicalsurface1MNaOH,. Photocurrent/ Photocurrent/22

SurfaceSEMimagesof

3N5calcinedatdifferentSurfaceSurfacelayerisexfoliatedonthesampleat590oCorhigherduetointernal RoleofthesurfacePL EIS-570oC,withSEIntensity/570oC,withoutSElayer590oC,withoutIntensity/

-Z/Z/---

570oC,withSElayer570oCwithoutSElaer590oC,withoutSElayer610oC,withoutSE

0 20004000600080001000012000Z/ThedensityThedensityofthebinationcentersThesurfaceThesurfacepassivationlayerisathinlayerofTa3-xN5-yOy(<15nm)highOafterremovalofthesurfacepassivationMechanismofthephotocurrent

SolarwatersplittingafterCo(OH)x5.58TaN/Co(OH), 5TaNli5 TaN,3TaN/210 Potential/Vvs.(3.8mA/cm2Thesolarphotocurrentat1.23(3.8mA/cm2Thesolarphotocurrentat1.23VRHEis5.5mA/cm2,whichismuchhiherthantherecordvalueofthereviousTa3N5electrodeRecordsolarphotocurrentofusual

Amountofproducts/Amountofproducts/

Augustynski,J.Mater.Chem.18,2298(2008)

Gratzel,Angew.Chem.Int.Ed.49,64055.5

00

Time/

TheFaradaicefficienciesofH2andO2areabout85%and74%,respectively.Thephotocurrentmainlycomesfromwatersplitting,notTa3N5photo-corrosion.Choi,Science343,990Thephotocurrentmainlycomesfromwatersplitting,notTa3N5photo-corrosion.SurfacecorrosiononInGaNandFe2O3

PhotocurrentPhotocurrent.

-0.4-0.20.00.81.0

PurePure

×Potential(VMingxueLi,WenjunLuo,etal.Appl.Phys.Lett.2011,92,262110

MinglongZhang,WenjunLuo,etal.Electrochem.Comm.2012,23,41

DapengCao,WenjunLuo*etal.Energy Morphologiesbeforeandaftersurface

PLspectraandI-Vcurvesintheaba

Intensity/AftercorrosionIntensity/

DarkcurrentDarkcurrent

FTO-bubblewithO1 1

Potential/Vvs.

DarkcurrentofODarkcurrentofO2reductiondecreasesaftersurfaceShallowleveldo andmorphologycontrolcanreducebulkbinationandimprovePECperformance.Surfacesegregationoftenhappensduringpreparationofsamples,whichoftenplayaroleas binationcenters.Surfacepretreatmentcanimprovethephotoelectrochemcialperformance.ThisstrategyisuniversalandcanofferaguidancetoimprovePECperformanceofothermaterials.SuppressingbackreactioncanshiftthephotocurrentonsetpotentialofaFe2O3photoanodeandalsoimprovethePECperformance.Aftermodification,recordsolarphotocurrentinBiVO4andTa3N5photoanodeshavebeenobtained.Especially,anefficientBiVO4photoanodewasusedtosplitnaturalseawateroutdoorsforthefirstArtificialPhotosyntheticChemicalProcess2012-202115billionTheJointCenterforArtificialPhotosynthesis(JCAP)2010-2015Ananowirep-ntandemcellwith10timeshigherthan

ApowderphotocatalystsystemwithSTH10%in

KoreaCenterforArtificialPhotosynthesis(KCAP)APEC/PVcellwithSTH APEC/PVcellwithSTHPapersinNature/Science/Naturesister

OurgoalinaPECwatersplitting XinWen,WenjunLuo*etJ.Mater.Chem.A1,15479ShengHuang,WenjunLuo*etJ.Phys.D:Appl.Phys.46,ZhongjieGuan,WenjunLuo*etm16,2929AporousphotoanodeAporousAAporousp-ntandemPECcellwithSTH10%andlow-Toexplore‘Si-like’forsolarwatersplittingiskeyHighcarriermobilityHighstabilityLowSuitableHighcarriermobilityHighstabilityLow

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