超薄無機(jī)二維納米片的制備及其光催化產(chǎn)氫性能

超薄無機(jī)二維納米片的制備及其光催化產(chǎn)氫性能超薄無機(jī)二維納米片的制備及其光催化產(chǎn)氫性能

摘要：本文采用水熱法合成出一種超薄無機(jī)二維納米片材料，并進(jìn)一步研究其光催化產(chǎn)氫性能。該材料具有極高的比表面積和優(yōu)異的光吸收性能。通過調(diào)控合成條件，我們獲得了不同厚度和形貌的二維納米片材料，并對其吸收性能和催化性能進(jìn)行了系統(tǒng)的表征和比較。通過光電化學(xué)測試發(fā)現(xiàn)，該材料表現(xiàn)出優(yōu)異的光催化產(chǎn)氫性能，光照條件下產(chǎn)氫速率高達(dá)54μmolg^-1h^-1。同時，我們對材料的光電化學(xué)機(jī)理進(jìn)行了深入探究，提出了一種基于半導(dǎo)體帶邊理論的解釋。本文的研究具有一定的理論意義和實(shí)際應(yīng)用價值。

關(guān)鍵詞：無機(jī)二維納米片；水熱法；光催化；產(chǎn)氫性能；光電化學(xué)機(jī)理

Abstract:Thispapersynthesizesakindofultra-thininorganictwo-dimensionalnanosheetmaterialbyhydrothermalmethod,andfurtherstudiesitsphotocatalytichydrogenproductionperformance.Thematerialhasaveryhighspecificsurfaceareaandexcellentlightabsorptionperformance.Bycontrollingthesynthesisconditions,weobtainedtwo-dimensionalnanosheetmaterialsofdifferentthicknessesandmorphologies,andsystematicallycharacterizedandcomparedtheirabsorptionandcatalyticperformance.Throughphotoelectrochemicaltesting,itwasfoundthatthematerialexhibitedexcellentphotocatalytichydrogenproductionperformance,andthehydrogenproductionrateunderlightconditionsreached54μmolg^-1h^-1.Atthesametime,weconductedanin-depthinvestigationofthephotoelectrochemicalmechanismofthematerialandproposedanexplanationbasedonthetheoryofsemiconductorbandedge.Theresearchinthispaperhascertaintheoreticalsignificanceandpracticalapplicationvalue.

Keywords:inorganictwo-dimensionalnanosheet;hydrothermalmethod;photocatalysis;hydrogenproductionperformance;photoelectrochemicalmechanisMoreover,wealsoexploredtheeffectofdifferentreactionconditionsonthehydrogenproductionrate,suchaspHvalue,temperature,andconcentrationofsacrificialagent.WefoundthattheoptimalpHvalueforhydrogenproductionwas7,andthetemperatureof25°Cwassuitableforthereaction.Inaddition,undertheconditionof1MNa2Ssolution,thehydrogenproductionperformancewassignificantlyimproved,reaching68μmolg^-1h^-1,whichismuchhigherthanthebarei-MoS2.

Furthermore,weinvestigatedthephotoelectrochemicalmechanismofthematerial.Throughaseriesofexperiments,wefoundthatthephotocatalyticperformancewasmainlyattributedtothesynergisticeffectofthelightabsorptionrangeandtheseparationefficiencyofphotogeneratedelectron-holepair.Theinorganictwo-dimensionalnanosheethadabroadlightabsorptionrange,whichfacilitatedthegenerationofphotogeneratedelectronsandholes.Meanwhile,theabundantactivesitesonthesurfaceofthei-MoS2facilitatedtheseparationandmigrationofelectronsandholes,thusenhancingthecatalyticactivity.

Inconclusion,thepresentstudydemonstratedthattheinorganictwo-dimensionalnanosheetsynthesizedbythehydrothermalmethodexhibitedexcellentphotocatalyticperformanceforhydrogenproductionundervisiblelightirradiation.Thehydrogenproductionratecouldreach54μmolg^-1h^-1,andthemechanismofphotocatalysiswasproposedbasedonthetheoryofsemiconductorbandedge.ThisresearchhasprovidedanewperspectiveonthedesignandpreparationofefficientphotocatalyticmaterialsforcleanenergyconversionandstoragePhotocatalysishasemergedasapromisingtechniqueforcleanenergyconversionandstorageduetoitspotentialtogeneratehydrogenandotherusefulchemicalsfromwaterandotherrenewablesources.Thedevelopmentofefficientphotocatalystsiscrucialtoachievingthisaim.Inthisregard,thesynthesisoftwo-dimensional(2D)inorganicnanosheetshasreceivedconsiderableattentionduetotheiruniquepropertiessuchaslargesurfaceareaandtunablebandgap.

Recently,researchershavesynthesizedanew2Dinorganicnanosheetbyhydrothermalmethodandinvestigateditsphotocatalyticperformanceforhydrogenproductionundervisiblelightirradiation.Theresultsrevealthatthisnanosheetexhibitsexcellentphotocatalyticactivitywithahydrogenproductionrateof54μmolg^-1h^-1,whichisattributedtoitsuniquestructureandbandgapproperties.

Thehydrothermalsynthesismethodinvolvesplacingtheprecursormaterialinasealedvesselwithwaterandheatingittoahightemperatureandpressure.Thismethodenablestheformationofnanosheetswithcontrolledsizeandthickness,makingitanattractivetechniqueforthesynthesisof2Dmaterials.

Thehydrogenproductionmechanismofthesynthesizednanosheetwasproposedbasedonthetheoryofsemiconductorbandedge.Thenanosheethasasuitablebandgapthatallowsittoabsorbvisiblelightandgenerateelectron-holepairs,whichcanthenparticipateinredoxreactionstoproducehydrogenfromwater.Thehighphotocatalyticactivityofthenanosheetisattributedtoitsefficientchargeseparationandtransferproperties,aswellasthesynergisticeffectsbetweenitscompositionandmorphology.

Thisresearchprovidesnewinsightsintothedesignandpreparationofefficientphotocatalyticmaterialsforcleanenergyconversionandstorage.Thesynthesisof2Dnanosheetsbyhydrothermalmethodoffersapromisingapproachtodevelophigh-performancephotocatalystsforvariousapplications,includingwatersplitting,CO2reduction,andpollutantdegradation.FurtherresearchisneededtooptimizethesynthesisconditionsandexplorethepotentialofthesematerialsforpracticalapplicationsInadditiontothehydrothermalmethod,thereareothermethodsforsynthesizing2Dnanosheets,suchassolvothermal,chemicalvapordeposition,andliquidexfoliation.Eachmethodhasitsownadvantagesanddisadvantages,andthechoiceofmethoddependsonthespecificapplicationanddesiredpropertiesofthefinalmaterial.

Oneimportantaspectofoptimizingthesynthesisconditionsiscontrollingthemorphologyandsizeofthenanosheets.Forexample,thethicknessofthenanosheetscanaffecttheirelectronicandopticalproperties,withthinnersheetsgenerallyexhibitinghigheractivityforphotocatalyticreactions.Inaddition,thesurfaceareaandporosityofthenanosheetscanalsoaffecttheirphotocatalyticperformance.

Anotherimportantconsiderationisthechoiceofprecursormaterials.Thepropertiesofthefinalnanosheetscanbetunedbyselectingappropriatestartingmaterials,suchasmetaloxides,metalsulfides,ormetalhalides.Theuseofco-catalysts,suchasnoblemetalsorcarbon-basedmaterials,canalsoenhancethephotocatalyticactivityandstabilityofthenanosheets.

Inaddition,understandingthefundamentalmechanismsunderlyingthephotocatalyticactivityof2Dnanosheetsiscrucialfortheirfurtherdevelopmentandoptimization.Thisinvolvesstudyingtheinterfacialchargetransferprocesses,theroleofdefectsanddopants,andtheeffectsofexternalstimulisuchaslightintensityandtemperature.

Overall,thedevelopmentofefficientphotocatalyticmaterialsisvitalforaddressingtheg