二維Ti3C2納米結(jié)構(gòu)調(diào)控及其對電化學(xué)性能的影響二維Ti3C2納米結(jié)構(gòu)調(diào)控及其對電化學(xué)性能的影響

摘要：

二維材料，在電子器件、光電器件和傳感器等領(lǐng)域具有廣泛的應(yīng)用前景。Ti3C2納米片是新型二維材料中的一種，因其高度可控制的結(jié)構(gòu)和出色的電化學(xué)性能而備受關(guān)注。本文通過控制材料生長溫度和氧氣氣氛等方法，成功地制備了不同結(jié)構(gòu)的二維Ti3C2納米片。通過SEM、TEM、XRD、XPS等手段對樣品進(jìn)行了表征，結(jié)果表明制備得到了高質(zhì)量的Ti3C2納米片。此外，利用展寬電位掃描法（CV）和循環(huán)伏安法（CA）等技術(shù)，詳細(xì)研究了不同結(jié)構(gòu)的Ti3C2納米片在鋰離子儲能器件中的電化學(xué)性能。結(jié)果表明，材料的結(jié)構(gòu)類型對其電化學(xué)性能有明顯的影響，其中羥基化Ti3C2納米片表現(xiàn)出了較好的儲能性能。本研究為二維Ti3C2納米片的制備和儲能方面的應(yīng)用提供了有益的參考。

關(guān)鍵詞：二維材料；Ti3C2納米片；納米結(jié)構(gòu)調(diào)控；電化學(xué)性能

Abstract:

Two-dimensionalmaterialshavebroadapplicationprospectsinelectronics,optoelectronics,andsensors.Ti3C2nanosheetsareatypeofnewtwo-dimensionalmaterialthathasreceivedmuchattentionduetotheirhighlycontrollablestructureandexcellentelectrochemicalperformance.Inthispaper,wesuccessfullypreparedTi3C2nanosheetswithvariousstructuresbycontrollingthegrowthtemperatureandoxygenatmosphere.ThesampleswerecharacterizedbySEM,TEM,XRD,XPS,andothermethods,andhigh-qualityTi3C2nanosheetswereobtained.Inaddition,theelectrochemicalperformanceofTi3C2nanosheetswithdifferentstructuresinlithium-ionenergystoragedeviceswasstudiedindetailusingtechniquessuchascyclicvoltammetry(CV)andgalvanostaticcharge-discharge(CA).Theresultsshowedthatthetypeofstructureofthematerialhasasignificantimpactonitselectrochemicalperformance,andthehydroxylatedTi3C2nanosheetsexhibitedbetterenergystorageperformance.Thisstudyprovidesvaluablereferenceforthepreparationandenergystorageapplicationoftwo-dimensionalTi3C2nanosheets.

Keywords:two-dimensionalmaterials;Ti3C2nanosheets;nanostructurecontrol;electrochemicalperformance.Two-dimensional(2D)materialshaveattractedwideattentionduetotheiruniquephysicalandchemicalproperties,aswellastheirpotentialapplicationsinvariousfields.Amongvarious2Dmaterials,Ti3C2nanosheetsderivedfromtheMXenefamilyhavebeenwidelyinvestigatedforenergystorageapplication.However,theelectrochemicalperformanceofTi3C2nanosheetsstronglydependsontheirstructure,whichcanbecontrolledbyvarioussyntheticmethods.

Inthisstudy,hydroxylatedTi3C2nanosheetsweresynthesizedandtheirelectrochemicalperformancewascomparedwithpristineTi3C2nanosheets.ItwasfoundthatthehydroxylatedTi3C2nanosheetsexhibitedbetterenergystorageperformance,asrevealedbythehigherspecificcapacitanceandbetterratecapabilityinbothCVandCAmeasurements.Thiscanbeattributedtotheintroductionof-OHgroups,whichnotonlyincreasedthesurfacehydrophilicitybutalsoenhancedthepseudocapacitivecontributiontotheoverallcapacitance.

Moreover,thenanostructurecontrolofTi3C2nanosheetswasstudiedbyadjustingthesynthesisconditionsincludingtheetchingtimeandhydrothermaltemperature.ItwasfoundthatlongeretchingtimeandhigherhydrothermaltemperatureledtotheformationofthinnerandmoreuniformTi3C2nanosheets,whichshowedimprovedelectrochemicalperformanceduetotheincreasedspecificsurfaceareaandimprovedionaccessibility.

Insummary,thisstudydemonstratedtheimportantroleofnanostructurecontrolintheelectrochemicalperformanceofTi3C2nanosheets,andprovidedvaluableinsightsintothepreparationandenergystorageapplicationof2Dmaterials.FurtheroptimizationofthesyntheticconditionsandsurfacefunctionalizationstrategiesmayleadtoevenbetterperformanceofTi3C2nanosheetsinenergystoragedevices.OnepotentialapplicationofTi3C2nanosheetsisinsupercapacitors,whichareelectrochemicalenergystoragedevicesthatcanrapidlystoreandreleaseenergy.ThehighsurfaceareaandconductivityofTi3C2nanosheetsmakethempromisingcandidatesforimprovingtheperformanceofsupercapacitors.

TointegrateTi3C2nanosheetsintoasupercapacitorelectrode,severalstrategieshavebeenexplored,includingdirectlydepositingthenanosheetsontoacurrentcollector,embeddingthemintoaporouscarbonmatrix,orusingthemasatemplatetosynthesizecomplexnanostructures.Ingeneral,thespecificcapacitanceandratecapabilityoftheresultingsupercapacitorelectrodesarestronglyinfluencedbythemorphology,thickness,andsurfacechemistryoftheTi3C2nanosheets.

Forexample,arecentstudyreportedthesynthesisofTi3C2@carbonnanofiberscompositesviaelectrospinningandsubsequentcarbonization.Theresultingcompositesexhibitedahighspecificcapacitanceof149.7F/gatacurrentdensityof0.5A/g,andgoodcyclingstabilityover5000cycles.TheenhancedelectrochemicalperformancewasattributedtothehighlyinterconnectedTi3C2nanosheetsandtheimprovedelectronandiontransportpropertiesprovidedbythecarbonmatrix.

AnotherapproachinvolvesmodifyingthesurfaceofTi3C2nanosheetswithfunctionalgroupsormetalions,whichcanalterthesurfacecharge,wettability,andredoxpropertiesofthenanosheets.Forexample,N-dopedTi3C2nanosheetsweresynthesizedbyannealingTi3C2/CnanocompositesinanNH3atmosphere.Theresultingnanosheetsexhibitedahighspecificcapacitanceof205F/gatacurrentdensityof0.5A/g,andgoodcyclingstabilityover5000cycles.TheimprovedperformancewasattributedtotheenhancedsurfacechargedensityandthesynergisticeffectbetweenN-dopingandTi3C2nanosheets.

Inadditiontosupercapacitors,Ti3C2nanosheetshavealsoshownpromiseinotherenergystorageandconversionapplications,suchaslithium-ionbatteries,sodium-ionbatteries,andhydrogenevolutionreactions.Forinstance,Ti3C2@TiO2hybridnanowireswerefabricatedbyatemplate-assistedmethodandusedasanodesinlithium-ionbatteries.Theresultingelectrodesexhibitedhighspecificcapacityandexcellentcyclingstability,whichwereattributedtothesynergisticeffectbetweentheTi3C2nanosheetsandtheTiO2nanowires.

Overall,thedevelopmentofTi3C2nanosheetsandtheirhybridswithotherfunctionalmaterialsholdsgreatpotentialforadvancingtheperformanceanddiversityofenergystorageandconversiondevices.Furtherresearchisneededtofullyexploittheuniquepropertiesandapplicationsofthese2Dtransitionmetalcarbides,andtoaddressthechallengesandopportunitiesassociatedwiththeirlarge-scaleproduction,practicalintegration,andperformanceoptimization.Inadditiontoenergystorageandconversionapplications,Ti3C2nanosheetsandtheirhybridshavealsoshownpotentialinotherfields.Forexample,Ti3C2-basedcompositeshavebeenutilizedashigh-performanceelectromagneticinterferenceshieldingmaterialsduetotheirexcellentelectricalconductivityandstrongabsorptionproperties.Ti3C2nanosheetshavealsobeenexploredforapplicationsincatalysis,sensing,andbiomedicine.

Incatalysis,Ti3C2nanosheetshavebeenshowntoexhibitsuperiorperformanceinthehydrogenationofnitroarenes,theoxidationofalcohols,andthedegradationoforganicdyes.ThehighsurfaceareaandedgesitesofTi3C2nanosheetsprovideabundantactivesitesforcatalyticreactions,whilethemetallicconductivityofTi3C2enhanceselectrontransferduringthereactions.

Insensing,Ti3C2-basednanocompositeshavebeenusedassensitivematerialsforthedetectionofvariousanalytes,suchasheavymetals,gases,andbiomolecules.TheuniquesurfacechemistryandelectronicpropertiesofTi3C2nanosheetsenableselectiveandsensitivedetectionoftargetmoleculeswithhighaccuracyandfastresponse.

Inbiomedicine,Ti3C2nanosheetshaveattractedattentionduetotheirbiocompatibilityanduniquephysicochemicalproperties.Ti3C2-basednanocompositeshavebeenexploredasdrugdeliverysystems,contrastagentsformedicalimaging,andscaffoldsfortissueengineering.ThehighsurfaceareaandporousstructureofTi3C2nanosheetsenableefficientdrugloadingandcontrolledrelease,whiletheirnear-infrared(NIR)absorbanceandmagneticpropertiesmakethempromisingcandidatesforimagingandtherapy.

Inconclusion,Ti3C2nanosheetsandtheirhybridshaveshowngreatpotentialinvariousfieldsduetotheiruniquepropertiesandversatileapplications.FurtherresearchisneededtoadvancethedevelopmentandoptimizationofTi3C2-basedmaterials,andtoexploretheirfullpotentialinenergy,catalysis,sensing,andbiomedicine.Withcontinuedprogress,Ti3C2nanosheetsandtheirhybridshavethepotentialtorevolutionizemanytechnologicalandbiomedicalfields.Ti3C2納米片和其混合物由于其獨(dú)特的性質(zhì)和多功能應(yīng)用而在多個領(lǐng)域顯示出巨大的潛力。在能源方面，Ti3C2納米片可以作為電池電極材料，顯示出良好的儲能性能和循環(huán)穩(wěn)定性。在催化方面，Ti3C2納米片的復(fù)合材料可以作為高效的催化劑。在感知方面，Ti3C2納米片可以作為傳感器，用于檢測有機(jī)分子、金屬離子和氣體。在生物醫(yī)學(xué)方面，Ti3C2納米片的生物相容性和低細(xì)胞毒性使其成為良好的生物醫(yī)學(xué)材料，可以用于藥物輸送和治療。

然而，目前還存在一些挑戰(zhàn)，需要進(jìn)一步的研究和改進(jìn)。例如，Ti3C2納米片的制備方法需要進(jìn)一步優(yōu)化，以提高制備效率和控制其尺寸和形貌。另外，對Ti3C2納米片的物理和化學(xué)性質(zhì)的研究也需要更深入的探索，以便更好地理解其性質(zhì)和應(yīng)用。在生物醫(yī)學(xué)方面，需要進(jìn)一步評估Ti3C2納米片的生物安全性和生物活性，以確保其在生物醫(yī)學(xué)應(yīng)用中的安全性和有效性。

總之，Ti3C2納米片及其混合物由于其獨(dú)特的性質(zhì)和多功能應(yīng)用，在各個領(lǐng)域都顯示出了巨大的潛力。需要進(jìn)一步研究和改進(jìn)，以發(fā)掘其全部潛力，從而推動其在能源、催化、感知和生物醫(yī)學(xué)領(lǐng)域的革命性應(yīng)用。除了上述提及的應(yīng)用領(lǐng)域外，Ti3C2納米片還在其他許多領(lǐng)域展現(xiàn)出了潛力。例如，在環(huán)境治理領(lǐng)域，Ti3C2納米片的復(fù)合材料可以作為高效的吸附劑，用于除去水中的污染物。在電子器件方面，Ti3C2納米片可以作為導(dǎo)電材料，用于制造柔性電子器件。

此外，Ti3C2納米片的層間距可以通過插入分子或離子來調(diào)控，這為其在電子器件、傳感器和催化劑等領(lǐng)域的使用提供了更多可能性。例如，研究人員已經(jīng)成功地將金屬離子（如Cu2+、Pb2+和Mo6+等）和大分子（如聚乙烯醇和聚丙烯酸等）插入Ti3C2納米片層間距中，從而制備出具有不同性質(zhì)和應(yīng)用的復(fù)合材料。

盡管Ti3C2納米片及其混合物在多個領(lǐng)域展現(xiàn)出巨大潛力，但其應(yīng)用還面臨一