简介：Ultrafastfiberlasersareingreatdemandforvariousapplications,suchasopticalcommunication,spectroscopy,biomedicaldiagnosis,andindustrialfabrication.Here,wereportthehighlystablefemtosecondpulsegenerationfromaMXenemode-lockedfiberlaser.Wehavepreparedthehigh-qualityTi3C2Txnanosheetsviatheetchingmethod,andcharacterizedtheirultrafastdynamicsandbroadbandnonlinearopticalresponses.Theobviousintensity-andwavelength-dependentnonlinearresponseshavebeenobservedandinvestigated.Inaddition,ahighlystablefemtosecondfiberlaserwithsignal-to-noiseratioupto70.7dBandcentralwavelengthof1567.3nmhasbeendelivered.Thestudymayprovidesomevaluabledesignguidelinesforthedevelopmentofultrafast,broadbandnonlinearopticalmodulators,andopennewavenuestowardadvancedphotonicdevicesbasedonMXenes.

简介：Inthispaper,AgBF4/[emim][BF4]supportedionicliquidmembranes(SILMs)werepreparedsuccessfullyforCO/N2separationusingnitrogenpressureimmobilizationprocedures.TheincorporationofAgBF4coulddecreasemembraneweightloss,improvethepressure-resistantability,andkeepthecriticalpressure(0.45MPa)oftheSILMs.ThehighviscosityandundissolvedAgBF4solidsinmembraneliquidwoulddisturbgasmoleculartransportthroughmembraneandgiverisetothegastransportresistance.Therefore,thegaspermeabilitydecreasedremarkablywithincreasingAgBF4carriercontentinthemembrane.WhenthemolarratioofAgBF4to[emim][BF4]increasedfrom0:1to0.3:1,theCO/N2selectivityoftheSILMsshowedagreatincreasefrom~1to~9at20°Cand0.4MPa,suggestingthatAgBF4wasaneffectivecarrierforCOfacilitatedtransport.ThepermeabilitiesofN2andCOincreasedathighertransmembranepressure,indicatingthatmoleculartransportwoulddominatethetransportprocessathighpressure.Thetemperature-dependentgaspermeabilityfollowedtheArrheniusequation.Moreover,thedifferencesbetweentheactivationenergiesofCOandN2becamelargerafterintroducingAgBF4,resultinginmoreobviousdecreaseintheCO/N2selectivityathigheroperatingtemperature.

简介：WehavesynthesizedandinvestigatedphysicalpropertiesoftwonewquaternarycompoundsGd2CoAl4T2(T=Si,Ge)singlecrystals,whichareisostructuraltoTb2NiAl4Ge2andEr2CoAl4Ge2.Themostimportantstructuralfeatureofthesematerialsistheanti-CaF2-typeCoAl4T2slabs.Thesematerialsshowmetallicbehaviorbelow300Kandthereisalong-rangeantiferromagnetic(AFM)transitionappearingat20and27KforGdCoAl4Ge2andGd2CoAl4Si2,respectively.ResistivityandheatcapacitymeasurementsalsoconfirmthesebulkAFMtransitions.Furtheranalysisindicatesthatthislong-rangeantiferromagnetismshouldresultfromthemagneticinteractionbetweenlocalmomentsofGd^3+ions.

简介：Severecapacityfadingandpoorhighrateperformanceoflithiumsulfur(Li-S)batterycausedby"shuttleeffect"andlowconductivityofsulfurhampersitsfurtherdevelopmentsandapplications.Li4Ti50i2(LTO)possesseshigh1whiumionconductivity,anditisalsocanbeusedasanactiveadsorbentforpolysulfide.Herein,fineLTOparticlecoatedcarbonnanofibers(CNF)werepreparedandaconductivenetworkbothforelectronandlithiumionwasbuilt,whichcangreatlypromotetheelectrochemicalconversionofpolysulfideandimprovetherateperformanceofLi-Sbatteries.Meanwhile,aquantityofadsorptionsitesisconstructedbydefectsofthesurfaceofLTO-CNFmembranetoeffectivelyimmobilizepolysulfide.ThemultifunctionalLTO-CNFinterlayercouldimpedetheshuttleeffectandenhaneecomprehensiveelectrochemicalperformanceofLi-Sbatteries,especiallyhighrateperformanee.WithsuchLTO-CNFinterlayer,theLi-Sbatterypresentsaspecificcapacityof641.9mAh/gat5Crate.After400cyclesat1C,acapacityof618.0mAh/gisretained.ThisworkprovidesafeasiblestrategytoachievehighperformanceofLi-Sbatteryforpracticalutilization.

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.

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.

简介：Uptothisdate,researchersarestillfacingdifficultiestoexpandthetechnologyofdirectmethanolfuelcells(DMFCs)becauseofthehighoverpotentialrequiredtooxidizethemethanolanditsrelativelypoorperformanceduetoCOpoisoningoftheleading-highcostanodecatalyst.Inlinewiththis,wehavesuccessfullymodifiedthemorphologicalstructureandcompositionoflowcostcobaltbased-metaloxides,MCo2O4(M=ZnandNi),withthesimpleandnobleuseofpolyvinylpyrrolidone(PVP)asgrowthmodifierandsurfacestabilizerduringthesynthesisofnanoparticlesinourpreviousreports,whichshownhighelectrocatalyticactivityandstrongstability.DuetothegoodperformanceofourPVPmodifiedMCo2O4towardspseudocapacitorandoxygenevolutionreactionapplications,wedecidedtoextendourresearchstudytomethanoloxidationreaction.Remarkably,PVPmodifiedNiCo2O4electrodedirectlygrownonnickelfoamsubstrateviaasimplehydrothermalprocessexhibitedbetterperformancecomparedwithPVPmodifiedZnCo2O4andNiCo2O4withoutPVP.Ithadobtainedaremarkablylowonsetpotentialof0.285Vandhighcurrentdensityof280mAcm-2,andshowngreatstabilityandhighpoisontoleranceduringacontinuousCVcyclingandChronoamperometrytest,whichattainedhighefficiencyof86.86%and98.52%,respectively.ThesepositiveresultsofPVPmodifiedNiCo2O4electrodetowardsMORmightbeattributedtoitshierarchical3Dnanostructureswithhighlymesoporoussurfaceandlargesurfaceareawhichmayhaveprovidednumerouselectroactivesites,andtheexceptionalcorrosionstabilityofNiCo2O4electrodeinalkalinesolution.