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2007 WS2 sensitized mesoporous TiO2 for efficient photocatalytic hydrogen production from water

郭裂锦 制氢 材料学 论文

CatalysisCommunications8(2007)

2007 WS2 sensitized mesoporous TiO2 for efficient photocatalytic hydrogen production from water

2007 WS2 sensitized mesoporous TiO2 for efficient photocatalytic hydrogen production from water

795–799

http://www.wendangxiazai.com/locate/catcom

WS2sensitizedmesoporousTiO2fore cientphotocatalytichydrogenproductionfromwaterundervisiblelightirradiation

DengweiJing,LiejinGuo

*

StateKeyLaboratoryofMFPE(SKMFPE),SchoolofEnergyandPowerEngineering,28WestXianningStreet,Xi’anJiaotongUniversity,

Xi’an710049,PRChina

Received4August2006;receivedinrevisedform16September2006;accepted16September2006

Availableonline22September2006

Abstract

NanosizedWS2sensitizedmesoporoustitaniumdioxide(TiO2)http://www.wendangxiazai.comparedwithTiO2substratewithoutmesopores,itwasfoundthatthemesoporoussubstrateisbene cialforlargeramountofWS2loadingandinhibitionofthelight-induceddetachmentofWS2particlesfromthesubstrateduringphotocatalyticreac-tion,whichleadstohigherphotocatalyticactivityandbetterstability.Wealsofoundthattherate-determiningstepforphotocatalytichydrogenproductionisthetransferofelectronsfromTiO2substratetoH+insolution,whentherecombinationbetweenelectronsandholeswithinTiO2couldbeneglected.Inthiscase,depositionofPtatthesurfaceofsemiconductorisindispensablefore cienthydrogenproduction.

Ó2006ElsevierB.V.Allrightsreserved.

Keywords:Photocatalyst;Semiconductor;Mesoporous;Sensitize;Hydrogen

1.Introduction

E cientproductionofhydrogenfromwaterbyuseofsolarenergyisoneofthemostattractivetargetsfortheresearchofphotocatalyticreactionsonsemiconductorsparticles[1,2].Amongthesephotocatalystsystemplati-nizedtitaniumdioxide(TiO2)hasbeenreportedtoproducehydrogenfromaqueoussolutionscontainingorganicmate-rials,suchasmethanol,solidcarbon,etc.,andevenfromwateritselfthoughwithalowyield[3–5].However,TiO2absorbonlyasmallfractionofsolarlight(lessthan5%).Manymethodshavebeenformulatedtoextendtheabsorp-tionofTiO2intovisiblelightregion.

Recently,e ortshavebeenmadetousesmallbandgapsemiconductorstosensitizeTiO2invisiblelight[6–8].Therearetwoprerequisitesforsuchheterogeneoussemi-conductorsystemstofunctione ciently:(i)thebandgapofthesensitizershouldbeneartheappropriatevaluefor

*

Correspondingauthor.Tel.:+862982668296;fax:+862982669033.E-mailaddress:lj_guo@http://www.wendangxiazai.com(L.Guo).

2007 WS2 sensitized mesoporous TiO2 for efficient photocatalytic hydrogen production from water

optimumutilizationofsolarradiantenergy,and(ii)itsconductionbandedgeshouldbehigherthanthatofTiO2toallowelectronstransferringfromthesensitizerstoTiO2.Unfortunately,mostofsemiconductorswithideallynarrowbandgaphaveconductionbandedgelowerthanthatofTiO2.WhileCdSwasfoundtobeanidealcandidatesatisfyingtheabovementionedtwoprerequisites,itisveryvulnerabletophoto-inducedcorrosionandthetoxicityofCd2+furtherlimiteditsapplication[9,10].Thusnewnar-rowbandgapsemiconductorwithidealopticalproperties,enoughstabilityandlowtoxicityishighlydesired.Narrowbandgapsemiconductors,suchasMoS2,Bi2S3andCdSe,havebeenstudiedassensitizers[11,12].Yuetal.[13]recentlyreporteddepositionofquantumsizedWS2onthesurfaceofTiO2.AlthoughbulkWS2hasconductionbandedgelowerthanthatofTiO2,thestrongquantumdotcon nemente ectsfornanosizedWS2makeitpossiblefore cienttransferofelectronsfromWS2toTiO2.Thus,degradationoforganicdyesunderilluminationofvisiblelightwasachieved.Thisreportinspiredustoapplysuchheterogeneouscompositephotocatalysttophotocatalytic

1566-7367/$-seefrontmatterÓ2006ElsevierB.V.Allrightsreserved.doi:10.1016/j.catcom.2006.09.009

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