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70 个结果
  • 简介:ThestrontiummodifiedwasteFCCcatalystwaspreparedbymagneticstirringmethodandcharacterizedbyXraydiffractometry(XRD),UV-Visdiffusereflectancespectrometry(DRS),X-rayphotoelectronspectroscopy(XPS)andscanningelectronmicroscopy(SEM).Meanwhile,itsphotocatalyticdenitrogenationperformancewasevaluatedintermsofitsabilitytodegradetheN-containingsimulationoilundervisiblelight.Amixtureofstrontiumnitratesolution(withaconcentrationof0.5mol/L)andwasteFCCcatalystwascalcinedat400℃for5hpriortotakingpartinthephotocatalyticdenitrogenationreaction.ThetestresultsshowedthatthephotocatalyticdegradationrateofpyridinecontainedinsimulationoilinthepresenceofthestrontiummodifiedFCCcatalystcouldreach92.0%undervisiblelightirradiationfor2.5h.

  • 标签: 脱氮性能 FCC废催化剂 光催化 催化裂化催化剂 X-射线光电子能谱 扫描电子显微镜
  • 简介:AsimpleapproachtosynthesizeZnOmicrostructureswasreportedusingdodecylamine,hexadecylamineandoleylamineastemplateagents.ThesynthesizedZnOwascharacterizedbyXRD,FESEM,TEM,EDSmapping,FTIR,UV-visDRS,RamanspectroscopyandBETanalysis.HierarchicalorientedZnOmicrostructureswereobtained.ThephotocatalyticperformanceofZnOpreparedwithdifferenttypesofalkylamineswasevaluatedbythedegradationofmethyleneblue(MB)andmethylorange(MO).Theresultssuggestedthatalkylaminecontrolthenucleation,growthandmorphologyofZnO.ThephotocatalyticpropertiesofZnOonthedegradationofMBandMOdecreasedwithincreasingthealkylchainlengthinalkylamine.

  • 标签: ZNO CONTROLLED PREPARATION ALKYLAMINE PHOTOCATALYTIC PROPERTY
  • 简介:Theshapeofnanostructurehasimportanteffectsontheirproperties,thereforeinthisstudy,wehavepreparedandcharacterizedthreedifferentmorphologiesofWO3nanostructuresi.e.nanorod,nanosphereandnanoplateforsurveyingshapeeffectontheirphotocatalyticpropertiestowarddegradationofRhodamineB(RhB)dye.ObtainedresultsshowthatnanoplateWO3incomparisonwithothershasthebestphotocatalyticactivity.AccordingtoSEM,andphotocatalyticdegradationresults,thereasonforthisbehavioristhesharpedgesandcornersofWO3nanoplates.Becauseoftheirlowcoordinationnumber,atomslocatedintheedgesandcornersoftheWO3nanoplateshavemoreactivity,adsorbmoreRhBandthereforegivemorephotocatalyticactivitytotheWO3nanoplates.UsingofdifferentscavengersshowedthathydroxylradicalsaremainlyresponsibleforphotocatalyticactivityofWO3nanoplatesandnanospheresbutforWO3nanorods,superoxideradicalsarethemainphotocatalyticdegradationagents.

  • 标签: 光催化活性 纳米结构 光催化降解性能 形态 罗丹明B 形状效应
  • 简介:Hydrogen,thecleanestandmostpromisingenergyvector,canbeproducedbysolarintochemicalenergyconversion,eitherbythephotocatalyticdirectsplittingofwaterintoH2andO2,or,moreefficiently,inthepresenceofsacrificialreagents,e.g.,intheso-calledphotoreformingoforganics.Efficientphotocatalyticmaterialsshouldnotonlybeabletoexploitsolarradiationtoproduceelectron–holepairs,butalsoensureenoughchargeseparationtoallowelectrontransferreactions,leadingtosolarenergydriventhermodynamicallyup-hillprocesses.RecentachievementsofourresearchgroupinthedevelopmentandtestingofinnovativeTiO2-basedphotocatalyticmaterialsarepresentedhere,togetherwithanoverviewonthemechanisticaspectsofwaterphotosplittingandphotoreformingoforganics.Photocatalyticmaterialswereeither(i)obtainedbysurfacemodificationofcommercialphotocatalysts,orproduced(ii)inpowderformbydifferenttechniques,includingtraditionalsolgelsynthesis,aimingatengineeringtheirelectronicstructure,andflamespraypyrolysisstartingfromorganicsolutionsoftheprecursors,or(iii)inintegratedform,toproducephotoelectrodeswithindevices,byradiofrequencymagnetronsputteringorbyelectrochemicalgrowthofnanotubearchitectures,orphotocatalyticmembranes,bysupersonicclusterbeamdeposition.

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  • 简介:hePhotocatalyticcharacterizationofTiO2supportedonactivecarbonwasinvestigatedforphotocatalyticdecompositionofdichloroaceticacid.ItwasfoundthatTiO2/ACexhibitedahigherphotocatalyticactivitythanpureTiO2.ThereasonisthatactivecarbonactingaspowerfuladsorbentsupportsmakeshighconcentrationenvironmentsoforganicpollutantmoleculesaroundTiO2particles.

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  • 简介:Highlyefficientsheet-likeBiPO4/zeoliteandball-flower-likeBiPO4/zeolitehadbeensuccessfullysynthesizedbyastandardhydrothermalmethod.Theadditionofassistantreagentinthehydrothermalsystemispromisingtoobtainspecialmorphology.Theassistantreagent(EDTA)actsasagrowthmodifierofcrystal.Thepossibleformationmechanismsofsheet-likeBiPO4/zeoliteandball-flower-likeBiPO4/zeolitewereschematicallydiscussed.Adetailedstudyofsheet-likeBiPO4/zeoliteandball-flower-likeBiPO4/zeoliteimpactedonthephotodecolorationmethyleneblue(MB)solutionshowedthatthecompositehadahighlyreusableandstablepropertyforlong-runphotocatalyticapplication.

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  • 简介:在玻璃表面上扔的一部PANI/TIO_2合成电影成功地用大音阶的第五音胶化dip-coating技术和化学氧化方法被准备。这部电影用XRD被描绘,AFM,并且紫外。结果证明TiO_2电影由塑造bothcuboid、分阶段执行锐钛矿的TiO_2nanoparticles组成。在这部电影的TiO_2的平均谷物尺寸是约20nm。在有PANI的涂层以后,粒子被变成塑造irregularspherical并且尺寸在直径被增加直到约35nm。UV-Visspectroscopy分析显示有PANI的TiO_2的涂层将导致相片的改进催化效率和TiO_2的相片反应的延期。thePANI/TiO_2电影的乐队差距是3.18eV。相片这部电影的催化性质被rhodamine-B的降级评估。67.1%rhodamine-B和83.2%能作为光催化剂用PANI/TiO_2合成电影在120min以内在日光和紫外照耀下面被降级,这被发现。

  • 标签: PANI/二氧化钛复合膜 溶胶/凝胶法 化学氧化法 光催化剂 制备 光催化活性
  • 简介:一张新奇相片催化反应堆被开发搬迁(从水的1,1二度(4-chlorophenyl)-2,2,2-trichloroethane)(DDT)。在反应堆,cenosphere被用来支持借助于大音阶的第五音胶化做的TiO2电影。因为cenospheres与TiO2,是涂的,他们的比重稍微从原版被增加0.6∼0.8到0.8∼0.9,以便他们能在水里被推迟。与bubbler的混合操作,在反应堆的水处于一个使流体化得好的状态。反应堆的底部是一张沙过滤器床,它能被用来阻止光催化剂被失去。反应堆的一个数学模型在二个主要有影响的因素被开发了:紫外(紫外)轻紧张和光催化剂集中。与如此的一个模型一起,反应堆能更相当被设计。

  • 标签: 光催化反应器 优化模型 水口 DDT 降解 TIO2薄膜
  • 简介:Theuseofsolarenergytodrivethechemicalandenergyprocesses,andthechemicalstorageofsolarenergyarethekeyelementstomovetoalow-carboneconomy,sustainablesocietyandtofosterenergytransition.Forthisreason,thereisafast-growingscientificinterestonthissubject,whichispartofthegeneraleffortforasolar-drivenchemistryandenergy,thechemistryofthefuture.Torealizethis

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  • 简介:Directphotontochemicalenergyconversionusingsemiconductor–electrocatalyst–electrolyteinterfaceshasbeenextensivelyinvestigatedformorethanahalfcentury.Manystudieshavefocusedonscreeningmaterialsforefficientphotocatalysis.Photocatalyticefficiencyhasbeenimprovedduringthisperiodbutisnotsufficientforindustrialcommercialization.Detailedelucidationonthephotocatalyticwatersplittingprocessleadstoconsecutivesixreactionstepswiththefundamentalparametersinvolved:Thephotocatalysisisinitiatedinvolvingphotophysicsderivedfromvarioussemiconductorproperties(1:photonabsorption,2:excitonseparation).Thegeneratedchargecarriersneedtobetransferredtosurfaceseffectivelyutilizingtheinterfaces(3:carrierdiffusion,4:carriertransport).Consequently,electrocatalysisfinishestheprocessbyproducingproductsonthesurface(5:catalyticefficiency,6:masstransferofreactantsandproducts).Successfulphotocatalyticwatersplittingrequirestheenhancementofefficiencyateachstage.Mostcritically,afundamentalunderstandingoftheinterfacialphenomenaishighlydesiredforestablishing'photocatalysisbydesign'concepts,wherethekineticbottleneckwithinaprocessisidentifiedbyfurtherimprovingthespecificpropertiesofphotocatalyticmaterialsasopposedtoblindmaterialscreening.Theoreticalmodelingusingtheidentifiedquantitativeparameterscaneffectivelypredictthetheoreticallyattainablephoton-conversionyields.Thisarticleprovidesanoverviewofthestate-of-the-arttheoreticalunderstandingofinterfacialproblemsmainlydevelopedinourlaboratory.Photocatalyticwatersplitting(especiallyhydrogenevolutiononmetalsurfaces)wasselectedasatopic,andthephotophysicalandelectrochemicalprocessesthatoccuratsemiconductor–metal,semiconductor–electrolyteandmetal–electrolyteinterfacesarediscussed.

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  • 简介:然而,锐钛矿二氧化钛是活跃光催化剂在底层上被使不能调动是困难的。水晶的TiO_2多孔的电影被阳极氧化在纯钛的表面上直接准备。这部电影然后经由甲基橙降级方法为光催化被使用。光催化剂上的阳极化电压,酸碱值价值,TiO_2电影区域和降级时间的效果被紫外可见的光谱分别地调查。阳极氧化在140V准备的TiO_2电影有最好的光催化能力,甲基橙的降级与酸增加被加速,这被显示。

  • 标签: 多孔氧化钛薄膜 阳极氧化法 制备 光催化活性 染料
  • 简介:Inthisarticle,low-pressurecontrolmethodsforacombinedarcsubmergednanoparticlesynthesissystem(ASNSS)wasproposedanddevelopedforTiO2nanoparticlefabrication.Thephotocatalyticreactioniscarriedoutinaphotochemicalreactor.TheUVlightisobtainedfromUV-lampswithwavelengthof(253.7±0.8)nm.TheUV-Visspectrometryisusedtomonitortheabsorbancespectraofmethyleneblueasafunctionofilluminationtime.ExperimentalresultsshowthattherateconstantofphotocatalyticreactionofTiO2nanoparticlesformethyleneblueis0.0365min^-1.Thesurfaceadsorptionplaysanimportantroleinthedecompositionofmethyleneblue.ExperimentalresultsindicatethattheTiO2nanoparticlefluidpossessesexcellentphotocatalyticactivityinphotodegradationofmethyleneblue.

  • 标签: 二氧化钛 纳米颗粒流 光催化性质 ASNSS
  • 简介:Todealwiththeincreasinglydeterioratingenvironmentproblems,moreandmoreharshrequirementsareputforwardforphotocatalysisapplication.Buildingsemiconductorheterostructureshasbeenproventobeanefficientwaytoenhancephotocatalyticperformance.AkindofCdTe/ZnOheterostructuresweresynthesizedbyahydrothermalandsuccessiveioniclayerabsorptionandreaction(SILAR)methodandachievedobviouslyefficientphotocatalyticperformance.Moreover,aftertheNionirradiationtreatment,thephotocatalyticactivitywasfurtherenhanced,whichcanbeascribedtotheintroductionofoxygenvacancydefects.ThephotocatalyticperformanceenhancementmechanismbycouplingconstructingheterostructuresandIonirradiationarefurtherstudiedtogiveusanoverallunderstandingonZnOnanowires.

  • 标签: N ion IRRADIATION CdTe/ZnO HETEROSTRUCTURES PHOTOCATALYTIC
  • 简介:Thesuppressionoftherecombinationofelectronsandholes(e–h)andtheenhancementofthelightabsorptionofsemiconductorsaretwokeypointstowardefficientphotocatalyticdegradation.Here,wereportafew-layerg-C3N4/α-MoO3nanoneedles(flg-C3N4/α-MoO3NNs)all-solid-stateZ-schememechanismphotocatalystsynthesizedviaatypicalhydrothermalmethodinacontrolledmanner.Therecombinationofthephoto-inducede–hpairscouldbeeffectivelyrestrainedbytheZ-schemepassagewaybetweentheflg-C3N4andα-MoO3NNsinthecomposite,whichcouldalsopromiseahighredoxabilitytodegradepollutants.Anditbecamepossibleforthepreparedphotocatalysttoabsorblightinawiderangeofwavelengths.Thedetailedmechanismwasstudiedbyelectronspin-resonancespectroscopy(ESR).Thelow-dimensionalnanostructureofthetwoconstituents(α-MoO3NNswithone-dimensionalstructureandflg-C3N4withtwo-dimensionalstructure)endowedthecompositewithvarietiesofexcellentphysicochemicalproperties,whichfacilitatedthetransferanddiffusionofthephotoelectronsandincreasedthespecificsurfaceareaandtheactivesites.The10wt%flg-C3N4/α-MoO3NNsshowedthebestphotocatalyticperformancetowardRhBdegradation,therateofwhichwas71.86%,~2.6timeshigherthanthatofα-MoO3NNs.

  • 标签: Flg-C3N4 α-MoO3 NANONEEDLES ALL-SOLID-STATE Z-scheme mechanism
  • 简介:TheTiO2nanomembranedopedbyREionswerepreparedbymixingREionsintoTiO2solutionandthephoto-catalyticpropertiesofthecoatingglasswithTiO2membranedopedbyREionstomethylbenzenedegradationunderultravioletwereinvestigated.AFMphotoesshowthatthesurfaceofcoatingglasswithTiO2nanomembranedopedbyCe3+,Ce4+,Y3+arecomposedofparticleswithdiametersof30~50nm.Theresearchesonphoto-catalyticpropertiesprovethatthesurfaceofcoatingglasswithTiO2nanomembranedopedbyREionspossessesgoodphotocatalyticpropertiesunderultravioletandthedegradationpercentsofmethylbenzenearemorethan90%whenthedegradationtimeisshorterthan160min.WhenthemoleratioofCe3+,Y3+,Ce4+toTiO2is0.002thedegradationpercentsofmethylbenzenearerespectively92.85%,91.87%and91.15%under254~365nmultravioletin50μg·ml-1methylbenzenesolution.ThephotocatalyticabilityofthesurfaceofcoatingglasswithTiO2nanomembranedopedbyCe3+underultraviolettodegrademethylbenzeneincreasesastheconcentrationsofREionsincreaseandtheiroptimumpercentageofdegradationare98.50%,97.50%and96.35.5%respectively.Thehighertheconcentrationofmethylbenzenesolutionthelowerthepercentsofthemethylbenzenedegradationofthecoatingglassare,andthebiggertheratiooftheareasofcoatingglasstothevolumeofmethylbenzenesolutionthehigherthedegradationeffectofmethylbenzeneis.

  • 标签: TIO2 nanomembrane DOPED RE IONS COATING
  • 简介:Transitionmetal-dopingcouldeffectivelyextendthelightresponserangeofTiO2photocatalystsfromtheultraviolet(UV)tothevisibleregion.Co-dopedbrookitetitaniumdioxide(Co–TiO2)photocatalystsweresynthesizedviathehydrothermalmethodwithtitaniumtetrachlorideastherawmaterialandcobaltchloridehexahydrateasthedopant.ThepreparedCo–TiO2photocatalystswerecharacterizedbyX-raydiffraction(XRD),scanningelectronmicroscopy(SEM),transmissionelectronmicroscopy(TEM),Ramanspectroscopy,X-rayphotoelectronspectroscopy(XPS)andUV–Visdiffusereflectancespectroscopy(UV–VisDRS).ThephotocatalyticactivitiesofCo–TiO2photocatalystswereevaluatedbyphotocatalyticdegradationofisopropanolalcohol(IPA),atypicalvolatileorganiccompound(VOC),undervisiblelight.TheinfluencesofdifferentCodopingrates,initialconcentrationsofIPAgasandtheamountsofphotocatalystadditionwerealsostudied.Atthesametime,theenhancementmechanismofcobaltionsasatrapforphotogeneratedholeswasdiscussed.Thus,wefoundtheoptimumdopingrate,initialconcentrationofIPAgasandamountofphotocatalysttoadd.TheresultsshowthatthemesoporousCo–TiO2photocatalystspossesssmallersizeparticles,largerspecificsurfacearea,lowerforbiddenbandgapenergy(Eg)andbetterphotocatalyticactivitythanpurebrookiteTiO2.WhenthedopingofCowas7%bymass,theinitialconcentrationofIPAgaswas1.0×10?6mol/LandtheadditionofCo–TiO2photocatalystswas50mg,thebestphotocatalyticactivitywasachieved.Furthermore,thedegradationrateofIPAwasupto91%,whichshowsgreatpotentialforwastewatertreatment.

  • 标签: Hydrothermal method CO-DOPED BROOKITE TITANIA VISIBLE-LIGHT