简介:ThehighlydispersedPt–ReOX(x≤1)sitesca.0.5nminsizewereformedviaasuccessiveandstronginteractionoftheReprecursorwithtitaniaandthenofthePtcomplexwithdepositedlow-valentrheniumoxideclusters.Thesize,chargeandchemicalcompositionwerecharacterizedbymeansofHRTEM/STEMwithEDXmapping,XPS,andFTIRS.ThesesiteswithRe/Pt=2wereshowntobehighlyactiveandselectiveinthehydrogenationofcarboxylicacidtoalcoholunderverymildconditions(T=130°C,P=50bar).ThereactionrateconstantforthehydrogenationofhexanoicacidincreasedlinearlywiththePtcontent.Asforthehomogeneouspincer-typeRu-organiccomplexes,theactivePt–ReOXsitescandissociateheterolyticallythemolecularhydrogenwiththeformationofhydroxylgroupsandPthydrideforhydrogenationofthecarboxylicgroup.Indeed,TOFof20h-1andselectivityof98%–99%areapproachingthevaluestypicalofhomogeneouscatalysts.Thefirstorderkineticsdescribedwelltheexperimentaldataobtainedinawiderangeofreactionconditions.
简介:Nickel-TiO2hybridcatalystsaresynthesizedbyelectrodepositionandtheircatalyticactivitywithrespecttothehydrogenevolutionreactionisanalyzed.Twotypesoftitaniumoxideparticles,whicharecommercialparticlesofdenseTiO2andmesoporousTiO2particlessynthesizedbyanaerosolmethod,areincorporatedintothematrixofthenickelcatalyst.BothnickelcatalystscontainingTiO2particlespresentedhighercatalyticactivitythantheconventionalnickelWattscatalyst.MesoporousTiO2-modifiednickelcatalystshowedthehighestcatalyticactivitytowardsHERinalkalinemedium.Inaddition,thistypeofnickelcatalystincreasesitscatalyticactivityafterageingtreatment,whichisanindicationofanincreaseintheelectro-activeareaoftheelectrode.
简介:TheeffectsofUVAphotoirradiatedCe(Ⅳ)dopedTiO2nanoparticle(CDTP)onratcoloncarcinomacellline(C26)growth,cellcycledistribution,andmorphologywerestudiedbyMTTassay,FlowCytometry,andfluorescentstaining.Theresultsindicatethatabout64.6%cellsarekilledafter24hby180μg·ml-1CDTPwhen8minexposedtoUVA,over90%deadfor30mingroup,relativeto18.7%,41.5%ofTiO2atthesameconditionrespectively.Hoe33258stainingofthefixedcellsrevealstypicalapoptoticstructures(apoptoticbodies),andcellsarearrestedinG0/G1phase.
简介:在经过NaOH-HCl预处理的镍钛合金基体上,采用溶胶-凝胶法制备纳米多孔TiO2薄膜;当涂覆一层致密内膜和一层多孔外膜时,可得到无裂纹的薄膜(试样TC1+1)。X射线衍射表明,TiO2薄膜由锐钛矿组成,在热处理的基体中还检测到少量的Ni4Ti3相。X射线光电子谱分析表明,试样TC1+1的TiO2薄膜完全覆盖了镍钛合金基体。试样TC1+1的表面亲水,接触角约为20°,紫外光照处理15min后接触角降低到(9.2±3.2)°。在0.9%NaCl溶液中的动电位极化实验表明,试样TC1+1的耐蚀性高于抛光的镍钛合金试样的。
简介:Inthispaper,athiol-functionalizednanophotocatalystMPTES/TiO_2wasfirstsynthesizedbyone-potmethodusingP123asatemplate.X-raydiffractionconfirmsthecompleteanatasecrystallineofthiol-functionalizedTiO_2,N_2adsorption-desorptionisothermdemonstratedthatthesematerialspossesshighsurfaceareaandmesoporousstructure.TheresultsofXPSshowthatMPTEShasbeensuccessfullypolymerizedinmesoporousstructuredTiO_2.Thephotodegradationofphenanthrene(PHE)wasinvestigatedundervisiblelightirradiation(λ>420nm)toevaluatethephotocatalyticactivityofthesematerials.BasedtheexperimentresultsofGC-Massanalysis,apossiblemechanismwasproposed.
简介:ZnOnanoconearrays(NCAs)decoratedwithblackTiO2nanoparticles(BTiO2NPs)wereuniformlyanchoredonthesurfaceofcarboncloth(CC)directlybyasimplyelectrochemicaldepositionmethod.ThusanovelB-TiO2NPs/ZnONCAs-CChierarchicalheterostructurewasformed.Itdisplayedsuperiorperformanceandachievedahigherphotocurrentover0.4mA·cm^-2beforetheonsetofthedarkcurrent,attributedtotheseparationofthephotogeneratedelectron-holepair.BasedontheB-TiO2NPs/ZnONCAs-CCheterostructure,thecatalystwasfabricatedforpromotingtheseparationofchargecarriers.Moreover,theintroductionofTi^3+andoxygenvacanciesonthesurfaceofTiO2NPsexpandedtheabsorptionbandedgeandenhancedtheelectricalconductivityaswellasthechargetransportationonthecatalyticsurface.ItindicatesthattheB-TiO2NPs/ZnONCAs-CCcompositeisbeneficialtotheimprovementofthephotoelectrochemical(PEC)activity.
简介:为使TiO2能够在可见光下发挥其于紫外激发下的高光催化活性,且易于从处理废水中分离,采用溶胶-凝胶法将TiO2与掺杂稀土离子Er3+的上转换发光剂Er3+:YAlO3结合,再将其负载到球形活性炭(SAC)表面,制备出可见光响应的负载型Er3+:YAlO3/TiO2-SAC光催化剂。通过XRD、EDS、SEM与FSA等手段对制备的光催化剂进行晶相、表面结构与元素分布、发光光谱等表征。以甲基橙为目标污染物,研究制备的光催化剂在可见光下的催化活性。结果表明,Er3+:YAlO3可以作为上转换发光材料,它吸收可见光并发射紫外光进而激发TiO2。700°C煅烧制备的催化剂具有最佳的光催化活性,可见光下表观反应速率常数可达0.0197min-1。
简介:InorganicbufferlayerssuchasSiO2orTiO2andtransparentconductiveindium-tin-oxide(ITO)filmswerepreparedonpolyethyleneterephthalate(PET)substratesbyionassisteddeposition(IAD)atroomtemperature,andtheeffectsofSiO2andTiO2onthebendingresistanceperformanceofflexibleITOfilmswereinvestigated.TheresultsshowthatITOfilmswithSiO2orTiO2bufferlayerhavebetterresistancestabilitiescomparedtooneswithoutthebufferlayerwhentheITOfilmsareinwardsbentatabendingradiusmorethan1.2cmandwhentheITOfilmsareoutwardsbentatabendingradiusfrom0.8cmto1.2cm.ITOfilmswithSiO2bufferlayerhavebetterresistancestabilitiescomparedtooneswithTiO2bufferlayeraftertheITOfilmsarebentseveralhundredsofcyclesatthesamebendingradius,fortheadhesionofSiO2isstrongerthanthatofTiO2.ThecompressivestressresultedfrominwardbendingleadstotheformationofmoredefectsintheITOfilmscomparedwiththetensilestressarisingfromoutwardbending.SiO2andTiO2bufferlayerscaneffectivelyimprovethecrystallinityofITOfilmsin(400),(440)directions.