简介:Inthisstudy,titaniumdioxidesupportedbymulti-walledcarbonnanotubes(MWCNTs/TiO2)andCr-dopedTiO2supportedbyMWCNTs(MWNTs/Cr-TiO2)weresynthesizedbythesol-gelmethod.Thepreparedsampleswerecharacterizedbytransmissionelectronmicroscopy,X-rayphotoelectronspectroscopy,X-raydiffraction,theBrunauerEmmett-Telleranalysis,andtheRamanspectroscopy.TheoxidationandefficiencyforremovalofSO2inasimulatedfluegaswereinvestigatedexperimentallyinafixed-bedreactor.The15%MWCNTs/Cr-Ti02sampledisplayedexcellentadsorptionproperties,andaSO2removalrateequatingto30.4151mg/gfromthesimulatedfluegascontaining2300μg/gofSO2,8%of02,and5%ofH20wasachievedunderoptimalconditionscoveringatemperatureof333.15K,andaspacevelocityof1275h^-1.TheadsorptionprocesswasenhancedbecauseCrdopingmodifiedtheporestructureandinhibitedthegraingrowthofTiO2.Inaddition,theFreundlichandLangmuirmodelsrevealedthatSO2wasmainlyadsorbedthroughchemicaladsorptiononthesamplesurfaces,andthethermodynamicmodelanalysisindicatedthattheadsorptionwasaspontaneous,exothermic,andentropy-reducingprocess.TheadsorptionkineticsofSO2canbedescribedbythepseudosecond-orderkineticandtheBanghamdynamicsmodels.Thepossiblereactionmechanisminvolvedindesulfurizationprocesswasalsoproposed.
简介:Formicacidphotodegradationisoneofthemostimportantreactionsinorganicpollutioncontrol,andhelpstoimprovethehydrogengenerationefficiencyintitaniumdioxidecatalyzedwaterphotodecomposition.BasedondensityfunctionaltheoryandReaxFFmoleculardynamics,theadsorption,diffusionandactivationofformicacidonthedifferentanataseTiO2(101),(001),(010)surfacesareinvestigated.TheresultshowsthattheadsorptionofCOOHonanataseTiO2surfaceshrinkstheenergygapbetweenthedehydrogenationintermediateCOOHandHCOO.OntheanataseTiO2(101)surface,theformicacidbreakstheO–Hbondatthefirststepwithactivationenergy0.24eV,andtheconsequentbreakofα-Hbecomemucheasierwithactivationenergy0.77eV.Thedissociationofα-HisthedeterminationstepoftheHCOOHdecomposition.
简介:WehaveexploitedagreenapproachtopreparelayeredtitanateNa2-xHxTi2O5·H2OnanosheetarraysonFTOsubstratebyhydrothermalhydrolysisoftitanium(IV)isopropoxide(TTIP)withaidsofNa2EDTAandTEOAasco-coordinationagents,whichwerethentreatedbyHNO3toreplaceNa+byH+,followedbyacalcinationat450℃totopotacticallytransformintoanataseTiO2nanosheetarrays.SEM,TEM,XRD,andRamanspectroscopyhavebeenemployedtocharacterizethenanosheetfilms.TheTiO2nanosheetarrayswerefurtherappliedaselectrontransportmaterialsofCH3NH3PbI3perovskitesolarcells,achievingpowerconversionefficiencyof6.99%.
简介:Inthisarticle,low-pressurecontrolmethodsforacombinedarcsubmergednanoparticlesynthesissystem(ASNSS)wasproposedanddevelopedforTiO2nanoparticlefabrication.Thephotocatalyticreactioniscarriedoutinaphotochemicalreactor.TheUVlightisobtainedfromUV-lampswithwavelengthof(253.7±0.8)nm.TheUV-Visspectrometryisusedtomonitortheabsorbancespectraofmethyleneblueasafunctionofilluminationtime.ExperimentalresultsshowthattherateconstantofphotocatalyticreactionofTiO2nanoparticlesformethyleneblueis0.0365min^-1.Thesurfaceadsorptionplaysanimportantroleinthedecompositionofmethyleneblue.ExperimentalresultsindicatethattheTiO2nanoparticlefluidpossessesexcellentphotocatalyticactivityinphotodegradationofmethyleneblue.
简介:AnewsupportedamorphouscatalystCoP/TiO2waspreparedbychemicalreductionandcharacterizedbyICP,XRD,TEM,BETandDSC.ItsapplicationindecomposingPH3tohighpurityphosphoranditscatalyticactivitywerestudied.Thedecompositionrateisover95%at450℃.Forcomparison,unsupportedCoPamorphouscatalystwaspreparedbythesamemethod.TheresultsuggeststhatCoP/TiO2exhibitshigherthermalstabilityandcatalyticactivitythanCoP,whichisattributedtothehighdispersionofCoPalloyparticlesonthesupport-TiO2.
简介:TheAl2O3-SiCcompositepowderswerepreparedinargonatmosphereusingcoalgangueandcarbonaceousmaterials