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500 个结果
  • 简介:HighactiveandstablegoldcatalystssupportedoncrystallineFe2O3andCeO2/Fe2O3werepreparedviathedeposition-precipitationmethod.ThecatalystwithaAuloadof1.0%calcinedat180°CshowedaCOconversionof100%at-8.9°C,whileAu/CeO2/Fe2O3convertedCOcompletelyat-16.1°C.Evenhavingbeencalcinedat500°C,Au/Fe2O3stillexhibitedsignificantcatalyticactivity,achievingfullconversionofCOat61.6°C.ThecatalystwithalowAuloadof0.5%couldconvertCOcompletelyatroomtemperatureandkepttheactivityunchangedforatleast150h.N2adsorption-desorptionmeasurementsshowthatthecrystallinesupportspossessedahighspecificsurfaceareaofabout200m2/g.CharacterizationsofX-raydiffractionandtransmissionelectronmicroscopyindicatethatgoldspecieswerehighlydispersedasnanoorsub-nanoparticlesonthesupports.Evenafterthecatalystwascalcinedat500°C,theAuparticlesremainedinanano-sizeofabout6―10nm.X-rayphotoelectronspectrarevealthatthesupportedAuexistedinmetallicstateAu0.ThemodificationofAu/Fe2O3byCeO2provedtobebeneficialtotheinhibitionofcrystallizationofFe2O3andthestabilizationofgoldparticlesindispersedstate,consequentlypromotingcatalyticactivity.

  • 标签: 金催化剂 CO氧化 氧化铁 Au/Fe2O3 去甲肾上腺素 X射线光电子能谱
  • 简介:Inthisletter,Fe2O3UFP(UltrafineParticles)hydrosolandorganosolwithhighthirdorderopticalnonlinearsusceptibility(3)havebeenreportedforthefirsttime.ThesurfacialmodificationofFe2O3UFPwithdodecylbenzenesulfonateions(DBS)canenhancethenonlinearopticalresponsethroughinterfacialconfinementofelectronmotion.Theinvolvedmechanismisdiscussed.

  • 标签: CONFINEMENT INTERFACIAL SUSCEPTIBILITY ULTRAFINE hinder coated
  • 简介:Fe2O3solwiththeparticlediameterof3-5nmwasflocculatedbytheadditionofSDS,andtheflocculateformedwasredispersedbythefurtheradditionofthatsurfactant.ThusthesurfactantbilayerwasformedonthesurfaceofFe2O3.Theemulsionpolymerizationofstyrene(St)adsolubilizedonthesurfactantadsorbedbilayerwascarriedoutbyinitiatorpotassiumpersulfate(KPS).TheUV-Visandsurfacephotovoltagespectra(SPS)indicatethattheFe2O3particleswereencapsulatedinpolystyrene(PSt)successfully.

  • 标签: FE2O3 nanoparticles Encapsulation Composite MICROSPHERES
  • 简介:Synthesisofinorganicnanostructureswithspecificsizeandwelldefinedmorphologieshasattractedconsiderableattentionduetotheirsuperiorelectrical,optical,magnetic,andchemical

  • 标签: 纳米结构 FE2O3 合成 笼状 自由 三维
  • 简介:Inthisarticle,nano-scaleAl/Fe2O3compositeswithdifferentmorphologiesweresuccessfullyobtainedbyasimpleelectrospinningtechnique,whichisbasedonasurfactant(polyvinylpyridine,PVP)inamixtureofN,N-dimethylformamide(DMF)and2-propanol.TheelectrospunAl/Fe2O3compositesexhibitedacrystalstructureandphasecompositionbyX-raydiffractionanalysis.ThedifferentmorphologiesoftheAl/Fe2O3compositeswerealsoobservedthroughscanningelectronmicroscopyandtransmissionelectronmicroscopy.Itwasfoundthattherathersimpleelectrospinningmethodusedtopreparethemorphology-controlledAl/Fe2O3compositesmayhavethepotentialforpreparationofpropellants,explosives,andpyrotechnicsinthefuture.

  • 标签: 下线 服务 迁移
  • 简介:Fe2O3/activecarbon(Fe2O3/AC)nanocompositeswerereadilyfabricatedbypyrolyzingFe3+impregnatedactivecarboninanitrogenatmosphere.Theas-preparedcompositeswerestudiedbyX-raypowderdiffraction(XRD),X-rayphotoelectronspectroscopy(XPS)andtransmissionelectronmicroscopy(TEM).Thecapacitivepropertyofthecompositeswasinvestigatedbycyclicvoltammetry(CV)andgalvanostaticcharge-dischargetest.Physicalcharacterizationsshowthattheγ-Fe2O3finegrainsdispersedintheACwell,withameansizeof21.24nm.Electrochemicaltestsin6mol/LKOHsolutionsindicatethattheas-preparednanocompositesexhibitedimprovedcapacitiveproperties.Thespecificcapacitance(SC)ofFe2O3/ACnanocompositeswasupto188.4F/gthatwasderivedfrombothelectrochemicaldouble-layercapacitanceandpseudo-capacitance,whichwas78%largerthanthatofpristineAC.AsymmetriccapacitorwithFe2O3/ACnanocompositesaselectrodeshowedanexcellentcyclingstability.TheSCwasonlyreducedbyafactorof9.2%after2000cyclesatacurrentdensityof1A/g.

  • 标签: 纳米复合材料 电容特性 制备 X-射线光电子能谱 X-射线粉末衍射 透射电子显微镜
  • 简介:利用室温液相还原、晶种生长的方法,成功的制备了大小形貌均一、性能稳定且具有磁性的Fe3O4@Cu2O复合纳米粒子,并且对制备的Fe3O4@Cu2O纳米粒子进行了光催化性能的研究.在以紫外光为光源的照射下,合成的Fe3O4@Cu2O纳米粒子对有机染料甲基蓝溶液起到很好的降解作用.更重要的是,在外加磁场的作用下,Fe3O4@Cu2O纳米粒子容易回收,具有良好的可循环利用性能.

  • 标签: Fe3O4@Cu2O纳米粒子 晶种生长 催化剂 循环利用性
  • 简介:本文通过电化学测量(循环伏安法)和量子化学计算(CNDO/2法)对几种原子簇化合物[(MoS4)2FeL]3-(其中配位体L为O2CH3CN,O2,O)的氧化还原活性进行了研究.实验测量与理论计算所得结果相符.研究结果表明这几种阴离子的还原皆为不可逆的单电子转移过程.它们接受电子的能力按如下次序递增:[(MoS4)2FeO2CH3CN]3-<[(MoS4)2FeO2]3-<[(MoS4)2FeO]3-

  • 标签: 氧化还原活性 Mo-Fe-S MoS4 eL 原子簇 单电子转移
  • 简介:Anewμ3-Otriiron(Ⅲ)complex[Fe3O(OBz)6(CH3OH)3](NO3)(CH3OH)2(HOBZ=benzoicacid)hasbeensynthesized,itsstructurehasbeendeterminedandvariabletemperaturemagneticsusceptilityhasalsobeenmeasured.Inthemolecule,threeironatomsformedanequilateraltrianglewithu3-Oincenter.ThefittingtothemagneticsusceptibilityshowedthatanintramolecularantiferromagneticexchangeinteractionoccurredbetweenironatomswithJ=-25.51cm-1,andaweakerintermolecularantiferromagneticexchangeinteractionoccurredwithzJ’=-2.30cm-1.

  • 标签: Crystal STRUCTURE MAGNETIC exchange triiron complex.
  • 简介:Thesolidaddofthefirstprotonatedzincoborophosphate,(H3O)Zn(H2O)2BP2O8·H2O(1),wassoventothermallysyn-thesizedbythereactionofZn(NO3)2·6H2OandH3BO3withH3PO4inamixedsolvent,andstructurallycharacterizedbysingle-ystalX-raydiffractionanalysis.ItcrystallizesinthehexagonalP6122,a=0.9604(4)nm,c=1.5297(6)nm,V=1.2218(8)nm^3,Dc=2.921g/cm^3,Z=6,F(000)=1080,μ=3.495mm^-1.Thestmchwefeaturesthatthetetrahedra-te-trahedrahdlcesinterconnectedbyoctahedraandstronghydro-gembondinteractionsformathree-dimensionalframework.Theprotonatedwatermoleculesarelocatedatuniquepositions.othercharacterizationsbyIRandthermalanalysisarealsode-scribed.

  • 标签: (H3O)Zn(H2O)2BP2O8·H2O 合成 结构 质子化 螺旋带状物 硼磷酸锌化合物
  • 简介:归纳了从钛铁矿中分离铁和二氧化钛的方法,包括亚熔盐法、预氧化法、还原锈蚀法;其次,初步总结了目前国内外制备Fe3O4磁性纳米颗粒和TiO2纳米粒子的方法。最后,对Fe3O4/TiO2复合材料的制备方法包括溶胶-凝胶法、微乳液法、均匀沉淀法作了梳理。Fe3O4/TiO2复合纳米材料很好地解决了单独使用TiO2作为废水处理催化剂,在实际应用过程中易随水流失,难以回收利用的问题,具有一定的实用性。

  • 标签: 光催化活性 磁性纳米粒子 Fe3O4/TiO2复合粒子 钛铁矿
  • 简介:Thenanomaterialsoftenexhibitveryinterestingelectrical,optical,magnetic,andchemicalproperties,whichcannotbeachievedbytheirbulkcounterparts[1-7].Thedevelopmentofuniformnanometersizedparticleshasbeenintensivelypursuedbecauseoftheirtechnologicalandfundamentalscientificimportance[8-15].Itissignificantthatnanostructuredmaterialscanbecontrollablyassembledintotherequiredgeometryontosubstrates,becomingthebasisofthenextgenerationofcomponentsanddevices[16-31].Thedevelopmentofnewmethodsandstrategiesfororganizingthenanoparticlebasicbuildingblocksintothedesiredstructuresisrequired.Superlatticesmadefromthesebuildingblocksgiveustheopportunitytostudynotonlythepropertiesoftheindividualbuildingblocks,butalsocollectiveeffects.Thesuperparamagneticironoxidenanocrystals(NCs)havebeenusedinthefieldsofbio-medicine,ferrofluids,refrigerationsystem,catalysis,particularlyinmagneticresonanceimaging,tissueengineering,anddrugdeliveryapplications[32-42].

  • 标签: 纳米晶体 超晶格 自组装 四氧化三铁 纳米结构材料 超顺磁性氧化铁
  • 简介:采用一步法合成了氨基化四氧化三铁(NH2-Fe3O4)磁性纳米材料,并以XRD,IR等手段对其进行了表征.将NH2-Fe3O4组装到磁性玻碳电极表面,得了NH2-Fe3O4修饰的磁玻碳电极,并以该修饰电极为工作电极,研究了其电化学性能.利用差分脉冲溶出伏安法研究了铅(Ⅱ)离子和铜(Ⅱ)离子在该修饰电极上的电化学行为.结果表明:NH2-Fe3O4纳米粒子可显著提高Pb2+和Cu2+在电极表面的富集量,提高溶出峰电流.由于差分脉冲溶出伏安曲线中Pb2+和Cu2+的溶出峰电位差较大,且没有相互干扰,所以该电极可用于Pb2+和Cu2+的同时测定.

  • 标签: 氨基化Fe3O4 磁性玻碳电极 PB2+ Cu2+
  • 简介:Thecrystalandmolecularstructuresof[(C3H7O)2PS2]2(CCDCNo.217201)weredeterminedbymeansofX-raycrystallography.ItcrystallizedinatriclinicsystemwithspacegroupP1^-andlatticeparametersa=0.82794(3)nm,b=0.84764(2)nm,c=0.85034(3)nm,α=97.78(3)°β=110.77(3)°,γ=94.95(3)°,V=0.54701(9)nm^3,Z=1.Inthismolecule,thetwodiisopropyldithiophosphategroups,[(C3H7O)2PS2]2,whichareparalleltoeachother,arelinkedbyanS--Sbondandthereexistinversioncentersinthemolecule,Inthestructure,theP=Sbondsinthetwodithiophosphateunitsaretrans-orientedtoeachother.

  • 标签: X射线结晶学 二烃基二硫代磷酸盐 中心对称 2 晶体结构 O'-二异丙基二硫代磷酸盐
  • 简介:在亲水性Fe3O4磁流体中,以甲基丙烯酸(MAA)为单体,N,N’-亚甲基双丙烯酰胺(MBA)为交联剂,采用光化学方法在水溶液体系中首先合成磁性聚甲基丙烯酸(PMAA)微球,进而在60℃下PMAA与稀土元素Dy离子反应合成具有荧光特性的磁性微球(FMPMs).运用振动样品磁强计(VSM),光子相关光谱仪,傅立叶变换红外光谱仪(FTIR)和热重-差热分析(TG-DTA)分别对微球的磁性能,平均水合粒径,化学组成和表面形貌进行了检测.结果表明,荧光磁性高分子微球有超顺磁性,呈很好的球形,表面含有丰富的稀土羧酸盐.

  • 标签: 荧光磁性高分子微球 甲基丙烯酸 光化学合成 制备 表征
  • 简介:Yb3+complexeswithtwonitrilotriaceticacidmoleculeswerepreparedandtheircompositionsweredeterminedasK3[Yb(nta)2(H2O)]*5H2OandNa3[Yb(nta)2]*6H2Obyelementalanalyses.Theirstructureswerecharacterizedbysingle-crystalX-raydiffractionanalyses.IncomplexK3[Yb(nta)2(H2O)]*5H2O,theYbN2O7partformsanine-coordinatemonocappedsquareantiprismaticstructure.IncomplexNa3[Yb(nta)2]*6H2O,theYbN2O6partformsaneight-coordinatesquareantiprismaticstructure.Itcanbeseenthattheoutercations(K+andNa+)greatlyaffectthecoordinationnumberandcoordinatestructurefromtheseresults.

  • 标签: 次氮基三乙酸 镱配合物 合成 晶体结构 X射线衍射
  • 简介:用离子交换法将具有Keggin结构TBA4H3PW7Mo3Cu2O38(H2O2(M=Fe2+,Co2+,Cu2+,Ni2+和Mn2+)嵌入到Zn2A1黏土中,得到层状化合物LDH-PW7Mo3Cu2O38(H2O2(M=Fe2+,Co2+,Cu2+,Ni2+和Mn2+),并用XRD,IR,uV对其进行了表征.结果表明:杂多阴离子进入黏土后,仍保留了其Keggin结构.利用合成的层状化合物为催化剂,以顺丁烯二酸与HzO。的环氧化反应为模型反应考察其催化活性,结果表明:层状化合物在环氧化反应中显示优良的催化性能.

  • 标签: 三元杂多阴离子 层状化合物 KEGGIN结构 环氧化反应
  • 简介:利用2-羟甲基吡啶(Hhmp)、三乙胺和Mn(CH3COO)2在室温下反应,合成了2D分子基磁性配位聚合物[Mn3Ⅱ(CH3COO)6(H2O)4·(H2O)2]n,其结晶为单斜空间群P21/c.在标题化合物中,Mn2+通过乙酸根离子连接形成线性三核Mn3(CH3COO)6单元;这些单元进一步通过乙酸根离子连接形成1个具有4-连接节点的二维层状44拓扑结构;最后,层与层之间通过氢键连接形成3D超分子网络结构.磁性研究表明,由于缺少反转中心,标题化合物在低温时表现出自旋倾斜反铁磁有序,这在纯乙酸基团构筑的体系中比较少见.

  • 标签: 配合物 晶体结构 磁性 自旋倾斜