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：Wepresentanultrabroadband,high-speedwavelength-sweptsourcebasedonaself-modulatedfemtosecondoscillator.Photoniccrystalfiberwaspumpedbyamode-lockedYb:CaF2laser,resultinginastrongspectralbroadeningfrom485to1800nm.Thepumplasercavitycouldberealignedinordertoachievetotalmode-lockingofthelongitudinalandtransverseTEM00andTEM01electromagneticmodes.Thisledtospatialoscillationsoftheoutputbeam,whichinducedmodulationofthecouplingefficiencytothefiber.Duetothefactthatnonlinearspectralbroadeningwasintensitydependent,thismechanismintroducedwavelengthsweepingatthefiberoutput.Thesweepingratecouldbeadjustedbetween7and21.5MHzbychangingthegeometryofthepumpcavity.Bycontrollingtheratioofthetransversemodeamplitudes,wewereabletotunethesweepingbandwidth,eventuallycoveringboththe1300nmand1700nmbioimagingtransparencywindows.Whencomparedwithpreviouslydemonstratedwavelength-sweptsources,ourconceptoffersmuchbroadertunabilityandhigherspeed.Moreover,itdoesnotrequireanadditionalintensitymodulator.

简介：Aunanoparticles(AuNPs)wereelectrodepositedatthehighlyorderedanataseTiO2nanotubearray(TiO2NA)electrodeundersonicating,andtheAuNP-TiO2NAsensorwascharacterizedbyscanningelectronmicroscope(SEM),X-rayphotoelectronspectroscopy(XPS),X-raydiffraction(XRD).ThephotoelectrochemicalexperimentsindicatetheAuNP-TiO2NAsensorhaslowerphotoelectro-resistance,higherphotoelectrocatalyticalactivityandstabilitythanthatofpureTiO2NAsensorunderthesameconditions.Theas-preparedsensorcanbeusedforthedeterminationofchemicaloxygendemand(COD)inrealsamples,andtheobtainedresultsarecomparablewellwiththoseofbystandardK2Cr2O7method.Themethodproposedissimple,fast,costeffective,andenvironmentallyfriendly.

简介：Herein,wereportthevictorioussynthesisofmetal-organicframeworks(MOFs)onTiO2nanotubes(NTs)usingalayer-by-layer(LbL)approach.HighlycrystallineandhomogenousthinfilmsofMOFsweregrownandcharacterizedusingXRD,SEM,FT-IRandUV/Visspectroscopy.Moreover,theutilizationoftheMOFfilmsassensitizerswasprobedinbespokeGraetzeltypeliquidjunctionsolarcells.TheconstructedcellperformancerevealedanIscof1.16mAcm–2,Vocof0.63V,FFof0.33,andEffof0.42%.Further,pumpprobetransientlaserspectroscopywasperformedtoinvestigatetheenergyandchargetransferdynamicsoftheMOFs/TiO2NTsinterface.Theresultsindicated86%injectionefficiency.Theultrafastpump-probespectroscopyallowstheinvestigationofthisprocessandthedifferencesbetweenMOFs.ItalsoshowedthattherelaxationoftheMOFchromophoresisincompetitionwithelectroninjectionintheTiO2motif.Thusthisstudyprovidesanewinsightintoelectrontransferfromphotoexcitedmetal-organicframeworks(MOFs)intotitaniumdioxide.

简介：WhileFe-basedoxygencarriers(OC)areregardedtobepromisingforchemicalloopingcombustion(CLC),thedecreaseofCO2selectivityduringdeepreductionprocessandthesevereagglomerationofFe2O3oftenoccuraftermultipleredoxcyclesduetothelowoxygenmobility.Herein,Fe-substitutedBahexaaluminates(BaFexAl12–xO19,denotedasBFxA-H,x=1and2)preparedbyamodifiedtwo-stepmethodexhibitednotonlyhigheramountofconvertedoxygen(Ot)andCH4conversion(77%and81%vs.17%and75%)thanthosepreparedbythetraditionalco-precipitationmethod(BFxA-C,x=1and2)butalsohighCO2selectivityabove92%duringthenearlywholereductionfromFe3+toFe2+.Furthermore,theBFxA-Hexhibitedtheexcellentrecyclabilityduring50cycles.ThebetterperformancewasascribedtothemarkedlyenhancedoxygenmobilitywhichresultedfromdominantoccupancyofFecationsinAl(5)sites(Fe5:71%and70%vs.49%and41%)inmirrorplanesofhexaaluminateleadingtolargeramountoflatticeoxygencoordinatedwithFe5(O–Fe5)(0.45and0.85mmol/gvs.0.31and0.50mmol/g).TheimprovementofoxygenmobilityalsofavoredthepreservationofchemicalstateofFecationsinhexaaluminatestructureinthere-oxidationstep,resultingintheexcellentrecyclabilityofBFxA-H.

简介：Two-dimensional(2D)materialshavebeendemonstratedtoexhibituniquepropertiesoriginatingfromits2Dnature.Inrecentyears,theconstructionof2Dmaterialshasbecomeatopicofgreatinterest.Thisarticlesummarizestherecentadvanceof2Dsupramolecularorganicframeworks(SOFs)whicharehomogeneouslyconstructedinsolutionphasethroughself-assemblyofrationallydesignedbuildingblocks.These2DSOFsaresolubleandstillmaintainstablenetworkstructuresinsolutions,whichexhibituniquenessnotonlyinstructuresbutalsoinproperties.Inthisconcisereview,theSOFs-relatedbackgroundisbrieflyintroducedfirstly,followedbyoutliningtheresearchprogressofsoluble2DSOFsfromtheperspectiveofmonomerdesign,assembly,andstructuralcharacterization.Thearticleendswithapersonaloutlookonthefuturedevelopmentofthisnewclassofsupramolecularpolymers.

简介：研究了考虑溶剂效应后2,1,3-苯并噻二唑衍生物中S原子被CH2—、O—和NH—取代引起的电子性质和光谱性质的变化,结果表明,与母体分子相比,O—取代引起的最高占据轨道能量(EHOMO)和最低空轨道能量(ELUMO)的变化很小,而CH2—和NH—取代引起的EHOMO和ELUMO的变化较明显,且CH2—和NH—取代后分子EHOMO的变化小于ELUMO的变化.CH2—取代导致最大吸收波长(λabs)和最大发射波长(λem)明显红移,而O—和NH—取代导致λabs和λem明显蓝移;而且取代后分子的吸收和发射光谱的振子强度都增大.

简介：TheSiO2nanoparticleswerecoatedonthesurfaceofgrapheneoxide(GO)bysol-gelmethodtogettheSiO2-Gcompound.TheSiO2-GwasrestoredandoleophylicallymodifiedtopreparehydrophobicmodifiedSiO2-G(HM-SiO2-G)whichwassubsequentlyaddedtosiliconerubbermatrixtopreparetwo-componentroomtemperaturevulcanized(RTV-2)thermalconductivesiliconerubber.Themorphology,chemicalstructureanddispersityofthemodifiedgraphenewerecharacterizedwithSEM,FTIR,Raman,andXPSmethods.Inaddition,theheat-resistancebehavior,mechanicalproperties,thermalconductivity,andelectricalconductivityoftheRTV-2siliconerubberwerealsostudiedsystematically.TheresultsshowedthattheSiO2nanoparticleswerecoatedongrapheneoxidesuccessfully,andHM-SiO2-GwasuniformlydispersedinRTV-2siliconerubber.TheadditionofHM-SiO2-Gcouldeffectivelyimprovethethermalstability,mechanicalpropertiesandthermalconductivityofRTV-2siliconerubberandhadnogreatinfluenceontheelectricalinsulationperformance.

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：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.