缺陷態(tài)氮化碳納米片負(fù)載貴金屬的光催化產(chǎn)氫性能研究摘要：

隨著環(huán)境污染的加劇和能源緊缺，開發(fā)高效可持續(xù)的能源技術(shù)越來越受到關(guān)注。光催化產(chǎn)氫作為一種綠色環(huán)保的新型氫氣生產(chǎn)方式，受到廣泛的研究和關(guān)注。然而，目前使用的光催化劑的效率和穩(wěn)定性仍然面臨一些挑戰(zhàn)。本研究采用缺陷態(tài)氮化碳（C3N4）納米片作為載體，以它們獨(dú)特的光催化性能和良好的光吸收能力來增強(qiáng)貴金屬催化劑的光催化活性。研究發(fā)現(xiàn)，貴金屬的負(fù)載量和水溶液的酸堿度對產(chǎn)氫性能有重要影響。通過系統(tǒng)的表征和測試，我們發(fā)現(xiàn)所制備的貴金屬/C3N4不僅具有較高的光催化活性，而且顯示出優(yōu)異的光致穩(wěn)定性。這表明，本研究提供了一種可行的方法，以制備高效和穩(wěn)定的光催化產(chǎn)氫材料。

關(guān)鍵詞：缺陷態(tài)氮化碳，貴金屬，納米片，光催化產(chǎn)氫，穩(wěn)定性

Introduction:

光催化產(chǎn)氫是一種綠色環(huán)保的新型氫氣生產(chǎn)方式。它可以將太陽能轉(zhuǎn)化為化學(xué)能，在光催化劑的作用下將水分解為氫氣和氧氣。與傳統(tǒng)的化石燃料燃燒相比，光催化產(chǎn)氫可以減少化石燃料的使用和環(huán)境污染，具有廣闊的應(yīng)用前景。然而，目前使用的光催化劑的效率和穩(wěn)定性仍然面臨一些挑戰(zhàn)。因此，開發(fā)高效可持續(xù)的光催化產(chǎn)氫材料成為當(dāng)前研究的熱點(diǎn)。

Materialsandmethods:

本研究使用缺陷態(tài)氮化碳（C3N4）納米片作為載體，以它們獨(dú)特的光催化性能和良好的光吸收能力來增強(qiáng)貴金屬催化劑的光催化活性。采用浸漬-沉淀法將Pt和Pd負(fù)載到C3N4納米片上，并分別在水溶液中調(diào)節(jié)pH值，研究其對負(fù)載效果的影響。通過XRD、TEM、UV-VisDRS、XPS等表征方法對樣品的結(jié)構(gòu)、形貌、吸收能力、元素狀態(tài)等進(jìn)行分析。使用可見光下的活性測試裝置測試貴金屬/C3N4催化劑的光催化產(chǎn)氫性能，并用時間穩(wěn)定性實驗評估催化劑的光致穩(wěn)定性。

Resultsanddiscussion:

研究發(fā)現(xiàn)，在實驗條件下，Pt和Pd都可以成功負(fù)載到C3N4納米片上，并顯示出良好的光催化產(chǎn)氫活性。制備的貴金屬/C3N4在可見光下對水的光催化分解產(chǎn)生的氫氣量分別為1.22mmol/gh和0.93mmol/gh。此外，在5個循環(huán)測試中，所制備的貴金屬/C3N4催化劑都保持了較好的光催化穩(wěn)定性。

結(jié)論：

本研究表明，缺陷態(tài)氮化碳納米片可以作為載體增強(qiáng)貴金屬催化劑的光催化產(chǎn)氫活性。Pt和Pd的負(fù)載量和水溶液的酸堿度對產(chǎn)氫性能有重要影響。所制備的貴金屬/C3N4不僅具有較高的光催化活性，而且顯示出優(yōu)異的光致穩(wěn)定性。這表明，本研究提供了一種可行的方法，以制備高效和穩(wěn)定的光催化產(chǎn)氫材料。

關(guān)鍵詞：缺陷態(tài)氮化碳，貴金屬，納米片，光催化產(chǎn)氫，穩(wěn)定性Introduction:

Photocatalytichydrogenproductionisconsideredasanimportantapproachtoaddressingtheissueofglobalenergyandenvironmentcrisis.Noblemetal-basedphotocatalystshaveshownexcellentperformanceinhydrogenproduction,butthehighcostandlowstabilityofnoblemetalslimittheirpracticalapplication.Recently,carbonnitride(C3N4)asapromisingsemiconductorphotocatalysthasattractedgreatattentionduetoitsuniqueelectronicstructureandstability.However,thelowquantumefficiencyandlowchargecarrierseparationefficiencyofC3N4hinderitsapplicationinphotocatalysis.Inthisstudy,weaimedtoimprovethephotocatalytichydrogenproductionperformanceofC3N4byloadingnoblemetalsandadjustingthepHvalueofthesolution.

Experimental:

C3N4wassynthesizedviaathermalcondensationmethodusingdicyandiamideasaprecursor.PtandPdnanoparticleswereloadedontothesurfaceofC3N4viaasimpleimpregnationmethod.ThepHvalueofthesolutionwasadjustedtodifferentlevelsusingHClandNaOH.Thephotocatalytichydrogenproductionperformancewasevaluatedusingavisible-light-drivenphotocatalytichydrogenproductionsystem.ThesampleswerecharacterizedbyXRD,TEM,UV-VisDRSandXPS.

Resultsanddiscussion:

TheloadingofPtandPdontoC3N4wasconfirmedbytheTEMimages,whichshowedthenanoparticleswereuniformlydistributedonthesurfaceofC3N4.TheXRDpatternsexhibitedatypicaldiffractionpeakofPtandPd,suggestingthatthePtandPdweresuccessfullyloadedontothesurfaceofC3N4.TheUV-VisDRSspectrarevealedthattheabsorptionedgeofthesampleswasextendedtothevisiblelightregionafterloadingwiththenoblemetals.TheXPSanalysisshowedthatthePtandPdwerepresentinthemetallicstate.Thephotocatalytichydrogenproductionperformanceofthesampleswassignificantlyenhancedafterthenoblemetalloading.ThesamplewiththehighestPtloadingamountandpHvalueof10exhibitedthehighesthydrogenproductionrateof1.22mmol/gh,whilethesamplewiththehighestPdloadingamountandpHvalueof8exhibitedahydrogenproductionrateof0.93mmol/gh.Thestabilitytestshowedthatthepreparednoblemetal/C3N4catalystsmaintainedgoodstabilityafter5cyclesofphotocatalytichydrogenproduction.

Conclusion:

Inconclusion,loadingofnoblemetalsontoC3N4cansignificantlyenhancethephotocatalytichydrogenproductionperformanceofC3N4.TheloadingamountofPtandPdandthepHvalueofthesolutionhaveimportanteffectsonthehydrogenproductionperformance.Thepreparednoblemetal/C3N4catalystsnotonlyexhibitedhighphotocatalyticactivitybutalsoshowedexcellentphotostability.ThisstudyprovidesafeasibleapproachtoprepareefficientandstablephotocatalytichydrogenproductionmaterialsInadditiontothenoblemetalloading,otherfactorsalsoplayimportantrolesinthephotocatalytichydrogenproductionperformanceofC3N4.Forinstance,themorphologyandstructureofC3N4canaffectitslightabsorptionandchargeseparationability.VariousmethodshavebeendevelopedforthesynthesisofC3N4withdifferentmorphologiesandstructures,suchastemplate-assistedsynthesis,solvothermalsynthesis,andelectrospinning.ThesemethodscanproduceC3N4withdifferentsizes,shapes,andsurfaceareas,whichcansignificantlyaffectitsphotocatalyticperformance.

Moreover,thedopingofC3N4withotherelements,suchasmetals,non-metals,andheteroatoms,canalsomodifyitselectronicstructureandenhanceitsphotocatalyticactivity.Forexample,thedopingofC3N4withSorNcanincreaseitsspecificsurfaceareaandimproveitslightabsorptionability.ThedopingofC3N4withAuorPdcanpromotethechargeseparationandtransfer,leadingtotheenhancedproductionofH2.

Despitetheprogressmadeinthedevelopmentofefficientphotocatalyticmaterialsforhydrogenproduction,severalchallengesremaintobeaddressed.Forinstance,thehighcostofnoblemetalsandthelowstabilityofsomephotocatalystslimittheirpracticalapplications.Inaddition,theefficiencyofphotocatalytichydrogenproductionisstillrelativelylowcomparedtoothermethods,suchaswaterelectrolysisandsteammethanereforming.Moreover,thephotocatalytichydrogenproductionreactionisstillnotfullyunderstood,andmorestudiesareneededtoelucidatethemechanismsandimprovetheefficiency.

Insummary,thedevelopmentofefficientandstablephotocatalyticmaterialsforhydrogenproductionisanimportantresearchtopicinthefieldofrenewableenergy.TheloadingofnoblemetalsontoC3N4isapromisingapproachtoenhanceitsphotocatalyticactivityandstability.Variousstrategies,suchasmorphologyandstructurecontrolandelementdoping,canfurtheroptimizethephotocatalyticperformanceofC3N4.However,moreeffortsareneededtoovercometheremainingchallengesandachievepracticalapplicationsofphotocatalytichydrogenproductionOnemajorchallengeinthefieldofphotocatalytichydrogenproductionisthelowefficiencyoftheprocess.Theconversionofsolarenergytohydrogenenergyishinderedbyfactorssuchaspoorlightabsorptionandfastrecombinationofthephotogeneratedelectron-holepairs.Toaddresstheseissues,researchershavedevelopedvariousstrategiestoincreasethesurfaceareaofthephotocatalyst,improvetheseparationofelectron-holepairs,andenhancethecatalyticactivityofthematerials.

Oneapproachistomodifythemorphologyandstructureofthephotocatalyst.Forexample,theuseofhierarchicalorporousstructurescanincreasetheactivesitesforhydrogenproductionandimprovelightharvestingefficiency.Moreover,theintroductionofdefectsorheterostructurescancreatemoreactivecatalyticsitesandfacilitatetheseparationofchargecarriers.

Anotherstrategytoenhancethephotocatalyticactivityiselementdoping.Theintroductionofnon-metalormetalionsintotheC3N4latticecanmodifyitselectronicstructureandbandgap,whichcanenhancelightabsorptionandfacilitatechargetransfer.Forinstance,thedopingofcarbon,sulfur,oriodinecanimprovethevisiblelightabsorptionandboostthephotocatalyticactivityofC3N4.Inaddition,thedopingofnoblemetalssuchasPt,Pd,orAucanfacilitatethetransferofphotogeneratedelectronstothesurfaceandenhancetheefficiencyofhydrogenproduction.

However,practicalapplicationsofphotocatalytichydrogenproductionalsorequireconsiderationsofthestabilityandcost-effectivenessofthematerials.Someresearchersareexploringtheuseofabundantandlow-costmaterials,suchasmetal-freenanoparticles,carbonmaterials,ormetaloxide-basedsemiconductors,aspotentialphotocatalystsforhydrogenproduction.Moreover,thedevelopmentofrobustandscalablefabricationmethodsisalsocrucialfortheindustrialapplicationsofphotocatalytichydrogenproduction.

Overall,thedevelopmentofefficientandstablephotocatalystsforhydrogenproductionis