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.
简介:Uniformlysizedα-Fe2O3hexagonalplateletsweresynthesizedbyahydrothermalprocessusingFe(OH)3suspensionandlargeamountofNaOH.ThereactionproductswerecharacterizedbyX-raydiffraction(XRD),scanningelectronmicroscopy(SEM),transmissionelectronmicroscopy(TEM),selectedareaelectrondiffraction(SAED),andavibratingsamplemagnetometer(VSM).Theresultsshowthatthehexagonalplateletsarefine,monodisperseandconsistingofsingle-crystals.Themagnetichysteresis(M-H)curveofthesamplesmeasuredatroomtemperatureindicatesthattheα-Fe2O3micro-plateletsexhibitferromagneticbehaviorswithrelativelylowcoercivity.
简介:Inthisletter,Fe2O3UFP(UltrafineParticles)hydrosolandorganosolwithhighthirdorderopticalnonlinearsusceptibility(3)havebeenreportedforthefirsttime.ThesurfacialmodificationofFe2O3UFPwithdodecylbenzenesulfonateions(DBS)canenhancethenonlinearopticalresponsethroughinterfacialconfinementofelectronmotion.Theinvolvedmechanismisdiscussed.
简介:AnapplicatiopnoftheopticalpyrometerisstudiedformeasuringmonochromaticemissivitiesofcementclinkerwithvariousFe2O3contnet.Theidsaofusing“brightnesstemperature”isintroducedintotheeimssivitymeasurement.Inthismethod,thereisnoneedformeasuringanactualtemperatureofsamplesurfaces,onlywithdeterminingbothbrightnesstemperaturesofasampleandablackbodycantherequiredemissivitybeevaluatedaccordingtoWien'sradiationlaw.Inpractice,thecementclinkerisregardedasagreybody,themonochromaticemissivityisapproximatelyequaltothetotalemissivity,soasingle-colouropticalpyrometerisappliedforthispurpose,Testmeasurementsarecarriedouton10kindsofcementclinkers,Experimentaldataaretreatedbytheleastsquaremethod.Asaresult,theemissivityvariationwithtemperatureatacertainFe2O3contentisquitewellrepresentedbyεn=a+bT.Furthermore,thisworkfirstreportedthattheeimissivitiesofcementclinkerchangeconsierablywithFe2O3contents.Inmultiplecementproductionthisconclusionisveryimportant.
简介:Fe2O3solwiththeparticlediameterof3-5nmwasflocculatedbytheadditionofSDS,andtheflocculateformedwasredispersedbythefurtheradditionofthatsurfactant.ThusthesurfactantbilayerwasformedonthesurfaceofFe2O3.Theemulsionpolymerizationofstyrene(St)adsolubilizedonthesurfactantadsorbedbilayerwascarriedoutbyinitiatorpotassiumpersulfate(KPS).TheUV-Visandsurfacephotovoltagespectra(SPS)indicatethattheFe2O3particleswereencapsulatedinpolystyrene(PSt)successfully.
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.
简介:A60%Fe/Al2O3catalystwaspreparedbytheco-precipitationmethod.ItwasreducedbyH2toproducemetallicFe,whichwasthensulfidedbyCS2toFe0.96SandFe3S4orphosphidedbytriphenylphosphine(PPh3)inliquidphasestoFe2PandFeP.Itwasfoundthattheironsulfides(Fe0.96SandFe3S4)exhibitedthelowactivityforthehydrodesulfurization(HDS)reactions.TheHDSactivitywasalsolowontheFe(metal)/Al2O3andFe2P/Al2O3catalystssincetheywereconvertedintoFe0.96SandFe3S4duringtheHDSreactions.Incontrast,theFeP/Al2O3wasfoundtobestableandactivefortheHDSreactions.Inparticular,FeP/Al2O3possessedsignificantlysmallerFePparticlesthanFeP/C,leadingtothesignificanthigherHDSactivityofFeP/Al2O3thanFeP/C.
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.
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.
简介:AfacilehydrothermalmethodwasdevelopedforthepreparationofFe2O3@CnanocompositesusingFeCl3·6H2Oasironsourceandglucoseascarbonsourceunderalkalinecondition.Themorphologyandstructureoftheas-preparedproductwereidentifiedbytransmissionelectronmicroscopy(TEM),highresolutiontransmissionelectronmicroscopy(HRTEM),field-emissionscanningelectronmicroscopy(FESEM),X-raydiffraction(XRD),Ramanspectroscopy,FourierTransforminfraredspectroscopy(FTIR),andthermogravimetricanalysis(TGA).Theas-prepareα-Fe2O3@Cnanocompositeswereemployedforsupercapacitorelectrodematerial.Thesynergisticcombinationofcarbonelectricaldouble-layercapacitanceandα-Fe2O3pseudo-capacitanceestablishedsuchnanocompositesasversatileplatformforhighperformancesupercapacitors.Thesynthesismethoddevelopedhereisexpectedtoobtainothermetaloxide/carboncomposite.
简介:AnewlayeredCu-basedoxychalcogenideBa3Fe2O5Cu2S2hasbeensynthesizedanditsmagneticandelectronicpropertieswererevealed.Ba3Fe2O5Cu2S2isbuiltupbyalternativelystacking[Cu2S2]2-layersandironperovskiteoxide[(FeO2)(BaO)(FeO2)]2-layersalongthecaxisthatareseparatedbybariumionswithFe3+fivefoldcoordinatedbyasquare-pyramidalarrangementofoxygen.Fromthebondvalencearguments,weinferredthatinlayeredCuCh-based(Ch=S,Se,Te)compoundsthe+3cationinperovskiteoxidesheetprefersasquarepyramidalsite,whilethelowervalencecationprefersthesquareplanarsites.Thestudiesonsusceptibility,transport,andopticalreflectivityindicatethatBa3Fe2O5Cu2S2isanantiferromagneticsemiconductorwithaNe′eltemperatureof121Kandanopticalbandgapof1.03eV.Themeasurementofheatcapacityfrom10Ktoroomtemperatureshowsnoanomalyat121K.TheDebyetemperatureisdeterminedtobe113K.TheoreticalcalculationsindicatethattheconductionbandminimumispredominantlycontributedbyO2pand3dstatesofFeionsthatantiferromagneticallyarrangedinFeO2layers.TheFe3dstatesarelocatedatlowerenergyandresultinanarrowbandgapincomparisonwiththatoftheisostructuralSr3Sc2O5Cu2S2.
简介:AnewSnO_2-Fe_2O_3/SWCNTs(single-walledcarbonnanotubes)ternarynanocompositewasfirstsynthesizedbyafacilehydrothermalapproach.SnO_2andFe_2O_3nanoparticles(NPs)werehomogeneouslylocatedonthesurfaceofSWCNTs,asconfirmedbyX-raydiffraction(XRD),transmissionelectronmicroscope(TEM)andenergydispersiveX-rayspectroscopy(EDX).Duetothesynergisticeffectofdifferentcomponents,theassynthesizedSnO_2-Fe_2O_3/SWCNTscompositeasananodematerialforlithium-ionbatteriesexhibitedexcellentelectrochemicalperformancewithahighcapacityof692mAh·g~(-1)whichcouldbemaintainedafter50cyclesat200mA·g~(-1).Evenatahighrateof2000mA·g~(-1),thecapacitywasstillremainedat656mAh·g~(-1).
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.
简介:与黄金和氧化铁nanoparticles并且与silibinin装载的PEGylated-PLGA随机的nanofibrous膜被electrospinning免职准备。nanofibrous膜能遥远地被控制并且由一盏激光灯或磁场激活在需求上释放生物代理人。nanosystems用扫描电子显微镜学被描绘,红外线的光谱学,原子磁性的回声光谱学,和thermogravimetric分析的Fourier变换。装载效率和药内容百分比的药被紫外力的光吸收光谱学决定。nanofibrous膜由相对低紧张的激光照耀或由一个磁场刺激了为至少60h显示出持续silibinin版本,没有爆炸效果。建议便宜electrospinning过程能够集合,经由一个一步舞过程,有外部地为控制的药交货要激活的金属性的nanoparticles的刺激应答的装载药的nanosystem。
简介:磁铁矿(Fe3有不同尺寸和形状的O4)nanoparticles被热分解方法综合。二条途径,非注射一个壶和热注射的方法,被设计详细调查生长机制。nanoparticles的尺寸和形状被调整先锋集中和持续时间时间决定,这被发现,它能好在我们的合成系统基于LaMer模型由机制解释了。monodisperseFe3O4nanoparticles从5nm有一条吝啬的直径到16nm,和形状进化从对球形三角形、立方。磁性是尺寸依赖者,和Fe3在关于在房间温度和最大的浸透磁化的5nm展览superparamagnetic性质的小尺寸的O4nanoparticles来临到78emu/g,而Fe3O4nanoparticles当直径增加到大约16nm时,开发铁磁性的性质。
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.