光电化学课件-研究进展

ThefirstpaperonaPECcellforsolarwatersplittingA.FujishimaandK.Honda,Nature238,37-38,1972Asinglephotoelectrodeforwatersplittingwithoutabias35%)e-e-e-e-e-2530iciency(%.u.)0V123EFH+/H2E1520rogeneffinflux(a127%1.23h+O2/H2OEg510lartohydPhoto12.7%2.23eVh+Photoanodecathode3004005006007008000SolWavelength(nm)Eg/e=1.23V+Vb(0.4V)+a(0.4V)+c(0.1V)+iR(0.1V)=2.23VMaruskaSolarEnergy20443(1978)Maruska,SolarEnergy.20,443(1978)Murphyetal.Int.J.HydrogenEnergy31,1999(2006)Ap-ntandemPECcelle-CBCBH+/H2e-eCBVBO/HOh+PSI21.6%VBO2/H2Oh+PSIIn-photoanodep-photocathodePSIIAp-ntandemPECcellisthemostpromisingsystemwithNozik,1976ApntandemPECcellisthemostpromisingsystemwithhigh-efficiencyandlowcostNewphotoelectrodematerials1.Suitablebandgapandpositions2.Highabsorptioncoefficient3Hihibilit4.Highstability3Highcarriermobilitygy5.LowcostBiVO4和NaTaO3270nmNaTaO3量子效率56%AKudoJAmChemSoc12530822003A.Kudo,J.Am.Chem.Soc.125,3082,2003BiVO4粉末450nm量子效率9%A.Kudo,J.Am.Chem.Soc.121,11459,1999GaN-ZnO固溶体的量子效率和可见光分解水出氢活性K.Domen,Nature440,295,2006第一个具有可见光分解纯水制氢的氧氮化合物g‐C3N4Nat.Mater.2009,8,76Sulfur G.LiuetalJ.Am.Chem.Soc.2012,134,9070BoronG.Liuetal,Angew.Chem.2013,125,6362PowderedphotocatalystsPhotoelectrodesEFeH+/H2-e--2O2/H2Oh+O2/H2Oh+(1) SeparatedH2and O2(2)EasierrecoveryAdvantagesh(2)Easierrecovery(3)HigherutilizationrateofmaterialsAhalfPECcellNatureMaterials,10,434,2011电催化剂Mo3S4使p‐Si光阴极出氢开启电势降低300‐800mVNatureMaterials,10,456,2011,光阴极在下具有最大的阴极光电流/2Cu2O光阴极在AM1.5下具有最大的阴极光电流7.5mA/cm2Naturematerials12,158,2013PECperformanceofnano-porousBiVO4PECperformanceofaFe2TiO5photoanodeAtotalPECcellATurnerScience2804251998A.Turner,Science,280,425,1998,aGaInP2photocathode+1GaAsPV高效分解水(10%),但光稳定性差,成本高Naturephotonics6,824,20123.1%aWO3photoanode+1DSSC1.2%aFe2O3photoanode+1DSSCKlNtC42195(2013)Krol,NatureCommun.4,2195(2013)aBiVO4photoanode+1SiPVaBiVO4photoanode+2SiPV3.6%4.9%aBiVO4photoanode+2SiPVUsualvisible-light-responsephotoanodesTa5dFe3dV3d0VTa5d20eVW5d2.7eV2.4eV2.0eV1.23VN22.0eVBi6sFe3dN2pO2pO2pO2pTNProf.DomenEltittdbditifWO3BiVO4Fe2O3Ta3N5Prof.KudoElectronicstructuresandbandpositionsofsomevisible-light-responsephotoanodesNHE2.Researchconceptse-EnergyEnvironSci44046(2011)eAngewChemIntEd5211016(2013)EnergyEnviron.Sci.4,4046(2011)Adv.Funct.Mater.22,3066(2012)Angew.Chem.Int.Ed.52,11016(2013)EEiSi7752(2014)EnergyEnviron.Sci.6,347(2013)H2OO2(1)(2)(3)EnergyEnviron.Sci.7,752(2014)Adv.EnergyMater.4,1301785(2014)H2Oh+2.Reducingsurfacerecombination1.Decreasingbulkrecombination3.Suppressingbackreaction2.1.1AnefficientBiVO4photoanodebydecreasingbulkrecombinationVanadylacetylacetonateionsolutionfdiBi(NO3)3acetylacetonatesolutionfordopingBi(NO3)3solutionMODmethodUltrasonicationClearsolution500rps/10sDriedat150oCGel470C/30ipDriedat150Cdoped-BiVO4470oC/30minWenjunLuoetal.EnergyEnviron.Sci.,2011,4,4046Effectofionsdopingonphotocurrent1.52.06+Mo6+A/cm2)1.52.0A/cm2)1.0W6+rrent(mA1.0urrent(mA0.5Fe3+Cr6+Ti4+PhotocurPureNb5+0.5Sn4+La3+In3+Zn2+Sr2+PurePhotocu0.0FeCrPIonsdopinginV5+sitePure0.0IonsdopinginBi3+siteOnlyMo6+,W6+dopingcanenhancethephotocurrentofBiVO4Increasediffusiondistanceofphotogeneratedelectronsbydecreasingresistance10pure3m-20cm4/F2)pure3%Mo2t/mAcmMo-BiVO4frontMoBiVOback51/C2(10101ocurrentBiVO4backBiVO4frontMo-BiVO4back-0.7-0.6-0.5-0.4-0.3-0.201Potential(VvsAg/AgCl)-0.4-0.20.00.20.40.60Potenital/VsAg/AgClPhotoBiVO4frontPotential(Vvs.Ag/AgCl)CarrierconcentrationincreasesafterModopingwhichPotenital/Vvs.Ag/AgClCarrierconcentrationincreasesafterModoping,whichincreasingdiffusiondistanceofphotogeneratedelectronsEffectof+6ionsdopingonphotocurrent2.5m2)Cr6+impuritylevel2.06+Mo6+mA/cm1.01.5W6+rrent(m000.5Cr6+hotocuPure0.0PhIonsdopinginV5+siteCr6+dopingisdeepenergylevel,whileMo6+orW6+isshallowlevelZongyanZhao,WenjunLuoetal.Phys.Lett.A,374,2010,4919DifferencebetweenshallowanddeepleveldopingCBCBMo6+/W6+，DonorlevelCr6+，e-h+RecombinationcenterVBShallowenergylevelisbetterthandeepenergylevelthandeepenergylevel2.1.2.Decreasediffusiondistanceofphotogeneratedholesbymorphologycontrola)b)0.81.0A/cm2)DensePorous200nm200nmc)d)0.40.6urrent(mABiVO4BiVO4FTOFTO05100.00.2Photocu500nm500nmFTOFTO0.51.0Potential(V)vs.RHEXinZhaoWenjunLuo*etalAdvEnergyMater41301785(2014)PorousanddenseBiVO4photoelectrodesXinZhao,WenjunLuo*etal.,Adv.EnergyMater.4,1301785(2014)Whyaporousphotoelectrodebetter?0.9cm2)PorousDense80100porousdense0.30.6urrent(mA/Dense4060denserbance(%)Absorbance501001502002503000.040CuThickness(nm)Porous350400450500550600650700020Absor102030PCE(%)PorousDense350400450500550600650700Wavelength(nm)0.50.6ficiencyPorousDense380400420440460480500520010IPWavelength(nm)020.30.4eperationEffDenseHigherlightabsorption?IPCE=ηabsηsepηint3804004204404604805005200.00.10.2ChargeSeHigherchargeseparationefficiency?Higherinterfacechargetransfer?Wavelength(nm)ChargeseparationefficiencyVisualizedevidenceforshorterholediffusiondistanceinaporousstructurea)b)p))200nm200nm200nm200nmMnOxMnOxc)d)200nmBiVO4BiVO4200nm200nmFTOFTOAmechanismforhigherperformanceinaporousphotoelectrodepeleBiVO4eleBiVO4FTOectrolyFTOectrolyOyteytePlPlan