外场作用下由工业TiOSO4液合成介孔二氧化钛（稀有金属材料与工程论文）

外场作用下由工业TiOSO4液合成介孔二氧化钛（稀有金属材料与工程论文） 第36卷xx在增刊39月稀有金属材料与工程RARE ME1AL MATER【ALS ANDENGINEERING Vo136，Supp13SeptemberxxSynthesis ofM esoporousTiO2from Industrial TiOSO4Solution underPotential Outfield Tian Congxue一，Zhang Zhao，Shen Jun，Luo Ni(1Sichuan University，Chengdu610065，China)(2Panzhihua University,Panzhihua617000，China)AbstractThe precursors of mesoporous titania weresynthesized viaposite templatesroute from industrial TiOS04solution under ultrasonic，microwave and hydrothermal field effectThe rate of hydrolysis and condensation of TiOS04solution was controlled byadjusting the pH value of the reacting systemMesoporous titaniawith anatasephase wasobtained af ter templatesremoval by calcinationsThe asprepared powder was characterizedby XRD，N2isothermal adsorption and desorptionmethod，particle size distribution，SEM，TEM，SAD andXPSExternal field withenhancing polaraction and soft hydrothermal condition isadaptive to prepare bettermesoporous titaniaUltrasonic vibrationpromotes the formation of mesoporous structureUnder microwave irradiation，mesoporous Ti02was synthesizedwith BETsurface area1466mg，average pore diameter257nm andcrystal size1365nmUltrasonicmicrowave irradiationsand hydrothermal condition arebetter thanconventional methodin formingmesopore andstabilizing thestructureKey wordsmesoporous titania；potential outf ield effect；industrial TiOS04solution；posite templatesynthesis CLCnumberO6144l；TQ42425Document codeAArticle ID1002一l85X (xx)$363l一061intr0ducti0n sincethe discoveryof mesoporoussilicas m41s，increasing attentionhad beenfocused onthe synthesis of mesoporous materials for their potentialwide applicationsdavis reviewedthe synthesisstudies andemerging applicationsof orderedporous materials【j-m esoporoustransition metal oxides arepromising notonly ascatalysts and molecular sievesbut alsoas highlyfunctional materials with shapespecif icand quantumeffect characteristicsof theordered inorganicskeletonsas oneof transitionmetaloxides，mesoporous titaniahas attracteda greatdeal ofattention dueto itsapplications invarious fields such as photocatalysts，adsorbents，photovoltaic cells，self-cleaning panels，electrochemical sensorsand newfunctional materialsetcit was first synthesizedusing alkylphosphate surfactants and titanium isopropoxide asreactants in1995【刚howeverremaining phosphorusfrom the template limitedits possibleuse asa catalystor catalystsupportphosphor usf leemesoporous titniawas suessfullyprepared usingdodecylam ineas templateltj thedirect synthesisof mesoporous materials with a cr y stallinewall has been consideredto bedi fi cultf orseveral reasonsone majorreason isthat phasetransformation fromamorphous tocr y stalline byheat treatmentusually induces the collapseof mesoporebecause thewallis toothin to retain thethree dimensionalmesoporousmaterialsduring cr ystallizationand itisofimpor tanceto controlthe balancebetween hydrolysisand condensation rate in the synthesisof mesoporous titaniatraditionally,plexing agents were usedto f orm titaniumplexes to decrease the hydrolysis ratepotential outfield，such asultrasonic，m icrowaveandhydrothermalconditions，can inf luence thereaction system，change theproper tiesof reactantsand reactionm echanismsonochemical effecthas beenproven tobe auseful techniquef or preparing novelmaterialswithunusual property,the applicationof ultrasoundto synthesizea widerange of materials hasbeen reviewedby suslick9】wang usedsonochemical methodto receiveddatexx一l106foundat ionitemsuppor ted by thenational naturalscience foundationof china(50474071，50274056)biographytian congxue，candidate forphd，college ofchemical engineering，sichuan university,chengdu610065，p rchina，tel008628854052l3，emailtcx7311163632稀有金属材料与工程第36卷prepare mesoporous tio2f romtitaniumisopropoxide，with wormhole1ike framework10m icrowaveirradiation hasbeen introducedto synthesisordered mesoporoussilica11cubic mesoporoussilica sba1612and inmodif icationof tio2for enhancedsurface properties13the reactingactivity isgreatly improvedand materialproper tiesare changedunder hydrother m alconditions，hydrother m al synthesisof mesoporoustitnia hasbeen repor tedby using organictitanate asreactant141w hilemost mesoporous titania isusually prepared byusingcostly organictitanium alkoxideand analyticalgrade inorgan ictitanate asprecursorsrecently，aqueous titanylsulfate(tioso4，ar)used asraw materialf or mesoporous titaniahasbeenreported16-18there isamount ofilmenite to prepare titaniumpigment viasulphate processin panzhihuaindustrial tioso4solution，the interm ediateproduct of the sulfateprocess，is cheapand available，with largeamount ofsulfuric acidtodecrease the hydrolysisand condensation rate，and isprom ising f orpreparing anatasephaseit isradically difficult to synthesis mesoporous titania via template routef rominorganic industrial tioso4solution f o rits highcontent oftitanium，iron andsulphuric acid，and itsrigorous hydrolysisconditionsthe self-assembly structure of surfactants，hydrolysisand condensationrateare ratherdi fi cultto cooperateposite surfactants were prom isingf or mesoporoustio2synthesis，f ornonionic surfactantdecreasetheexclusion ofnonpolar part ofionic surfactant，easier tof orm thehexagonal micelle；and wehad alreadyprepared mesoporous titania f romindustrialtioso4solution viaposite surfactantsself-assembly route19,20here，ultrasonic，microwave andhyd rotherm al methodswere usedtosynthesismesoporoustitaniafrom industrialtioso4solution toinvestigate the effect ofpotential outfields ontheformationof mesoporous struct u re2experimental procedures21synthesis industrialtioso4solution(from titaniumindust rycoof pangangcoltd，china)is posedof tio2=26025gl，2h2so4tio2=197，fetio2=019(叭)ethanol，trietha nolamine(tea)and cetyltrimethylammonium bromide(ctab)were allanalytical reagentseo2opotoeo2o(p一123)was amercial productfrom aldricha11these reactantswereused asreceived withoutf urther purif icationthe precursorsof m esoporoustitaniawere preparedasf o llowsctaband p123were dissolvedintheposite solutionof ethanoland waterunder vigoroussti ringf o r lhtea wasadded into the surfactantssolution andsti redfo r another30minthen，indust rialtioso4solution wasslowly dropwiseadded into the abovesolution underpotential outfield，such asultrasonic i radiation(cps一3sonif ierproduced byshanghai shengpuultrasonic equipmentfactory ofchina，ti horn，20khz，input power120wcmz)，microwave iradiation(microwave oven，2450mhz，input power100w)，hydrother m al synthesis(60ml autoclaveprovided thetef lonliner at393k，loading degree80)，and thecontrastive samplewas prepared withoutany potential outfieldin allconditions，the molarratio oftictabp一123was keptat101o1h20ti was41and theph valueof thereaction systemwascontrolledabout10by addingsulfuric acidaf terreacting fo r60min，the obtainedwhite sol was transfered fromreactor intoa closeiodimetric bottle，aging at293k for3h and then agingat333k for anotherl0hthe solwas washedwith distilledwater threetimes andethanol twice，then filtratedthe gelpowderwas prepared after thesolwasdried at373k for5h andgrounded topowderat last，the powderwas calcinedat673k for2h inair flow，and mesoporoustitania wasobtainedthe samplesprepared underultrasonic iradiation，microwaveiradiation，hydrother m alcondition and conventional method，were markedas a，b，c andd respectively22characterization lowangle(1。 10。 )and wideangle(20。 O。 )xray powderdiffraction(xrd)pat terns were obtained byusing aphilipsdif fractometer(xpertpro mpd)，with cuka irradiation(40kv and40ma)the nitrogenadsorptionanddesor ptionisother msweremeasured at77k usinga quantachromeanalyzer(nova1000e)，and themeasurements werecarried outafterdr ying the samples at573k for3h undervacuum conditionbrunauer-emmet tteller(bet)surface areas(et)were calculated from thelinear part ofthe betplot usingmultipoint methodporesizedistributions werecalculated usingt hebar retjoynerhalenda(bjh)model withhalsey增刊3tian congxueet alsynthesisofmesoporous tio2from industrialtioso4solution underpotential outfield633equations，the porevolume()and averageporediameter(dp)wereobtainedfrom thebjh poresize distribution21particle sizedistributions weremeasured usingparticle sizeanalyzer(jl一1166)scanning electron microscopy(sem)studies werecarried outonajeol electronmicroscope(jsm一5900lv)transmission electronmicroscopy(jemi oocx)was usedto detectthe morphologyoftheparticle anddetermine the crystal formthe binding energy ofti ando wasmeasured onthe xray photoelectronspectroscopy(xsam800，kratos)3results anddiscussion31structure analysis of mesoporoustitania the lowangle xrd patterns of m esoporoustitania are showed in fig1aall thesamples haveobvious peaksat about2。 which rangef rom179。 to216。 corresponding thedspace from493nm to408nm(1isted inTable1)，indicating their mesoporous structureThelowangle peaksof ultrasonicandmicrowave irradiationsare sharp asa resultof itshigh mesoporousorder，and sample Bs is the narrowestFig1b showsthe wideangle powderXRD patterns of mesoporoustitaniaAll thepeaks arein aordancewith the standard anatase(JCPDS211272)，meaning thatthey areanatase withtetragonal phaseThe diffractionintensity of sample Cis the largest，indicating sampleC has the岛占a量20(。 )Fig1XRDpaernsof mesoporousTiO2Lowangle(a)and(b)wideangle highestcr ystalline，which attributestothehigh reactingtemperature quickeningup the cr y stallization rateThe crystallinityof sample A and B isbetter thansample D，indicating thermal effect ofultrasound and microwave aeleratescrystal growthThe grainsize Looo aordingto Sche rers equationcalculatedfrom latticeplane (101)of anataseis listedin table1，and the results confirmsthediscussion abovenitrogen isothermsand poresize distributionare showing in fig2a andfig2band thecalculated poreparameters(abet，and dp)are listedin table1一g笔relative pressure，p qpore diameternm fig2nitrogen isotherms(a)and poresize distribution(b)ofmesoporous titama table1physicochemical characteristicsfor mesoporousti02all isothermsshow typeiv curveswith aclear typeh1hysteresis loop，characterizing theyare mesoporousmaterials，withanarrow poresize distributionand dplarger than22nmthe abetof sample b isthelargest，while sampleds isthe smallestthe mesoporous str u ctureofthesamplesprepared underpotential outfie1d isbetter thanthat ofconventiona1methodg0，pqj0g三o o o o ooooo634稀有金属材料与工程第36卷m icrowaveand ultrasonicirradiations can aelerate positesurfactant templateself-assemble toform micellefortheirpolar effect，and metatitanic acid hydrolyzedfrom industrialtioso4congregates onthe micellevia molecularinteraction toform mesoporousorganic-inorganic positethrough cooperativeroutew hilehydrother mal treatmentspeeded upthe crystallizationrate，the poly-condensationrate of metatitanicacid wasfaster thanthe micellecongregation rate，the mesoporousorder ispoorthe thermal effect aeleratesthe cry stallizationrateof mesoporoustitania，as showsobvious in fig1bthe collapseof bubblespromoted byultrasound generateslocalized hotspots withtransient temperatureat about5000k，pressure atabout20m pa，and heatingand coolingrates greaterthan10ks一【22these conditionsaelerate thehydrolysis reaction，and ultrasonicvibration aeleratesthe self-assembly rateof positesurfactantsandclose linkbetween ti and hydroxyl(-oh)of micelle，benef icialfor synthesisofmesoporousmaterialsther male fect of microwave mayunifor mly heatthe reactingsystem ina very shorttime，shor tenthe inductionperiod ofnucleation process，promote buddingof crystalnucleus andspeed upcrystal growthratearafat studiedthe synthesisof yand zsm-5zeolites undermicrowave irradiation【23contrast toconventionalmethodnonthermal effectof microwavecanaeleratethe extentof self-polymerization oftitanium andsurfactants，stabilizing mesoporous structurehydrother mal synthesis is caried outin nonequilibriumstate，changing theproper tiesof reactants，developing reactivityand promotingfor mationofmetastable phaseand themolecule ofp-123acted asatemplatewith lotsof hydroxyl(-oh)in itsmolecular chainin thehyd rothermalsystem，theeffectof hydrogenbond wasstrengthened and(ho)3-(ti-o)-h solcould formaround themicelle tofor mthe mesoporous structuresample chasthelargest anddpthe mostlikely reasonfor thatmay attributetothefact thatmetastable phaseis form edunder hydrothermalcondition，high reactingtemperature urgesthecrystallization step，and mesoporousstruct ureis morestable duringcalcinationthe porestr ucturalproper tiesof sampled arethe poorestultrasonic vibrationandmicrowaveiradiationmay impeloriented polymerizationof titania andthemicelle，har monize thehydrolysis rateof industrialtioso4solution andself-assembly rateof positesurfactants，promising forthe synthesisofmesoporoustitaniahydrother mal effectimproves thestability ofmesoporousstr ucture32m orphologyand microstructureanalysisofmesoporoustitania theaverage particle size(dav)is listedin table1，all ofthem arealmost thesamethe particlesize distributionof sample a isca011m，and samplebsisca0312pmthe sem micrographs ofsample aandbare giveninfig3，the dispersedpar ticlesand agglomeratescan obviouslybe seendue tothermaleffectofmicrowave，t hem orphologyofsampleb(fig3b)is moreorbicular thansample as(fig3a)high synthesistemperature increasesthecrystallizationand particle growthrates，resulting inday ofsampleblarger thanasbecause surfaceoh onmetatitanicacidtends tobe boundtogetherthe primary par ticles agglomeratethe larger par ticlesshown inf ig3the aggregatedparticlesare allwith iregular morp hologythe temmicrograph andselected areadiffraction fsad)pattern ofsampleaareshowedinfig4aandfig4bfrom fig4a，the primary particles rangefrom10nm to50nm，and theycongregate thelargerparticles asshowinginf ig2asad pattern(fig4b)includes aseries ofcontinuous debyeschererrings，denoting anatasecrystal latticeplanes respectivelythe ringpattern confirms thepolycr ystalline anatasespecimen，fig3semmicrographsfor mesoporoustio2(a)sampleaand(b)sampleb增刊3tian congxueet alsynthesisofmesoporous tio2from industrialtioso4solution underpotential outfield635consistent withtheresultof xrdanalysisaf terusing xpspeak fitting programto distinguishpeaks，the bindingenergy valueof o for otiand ti for tio ismarked out(fig5)the bindingenergy oftio bondisthesame asstandard anatase(2p23is4587ev,2p12is4644ev)(fig5b)while thebindingenergy of o=ti is52964ev(fig5a)，paring withthestandard0一yisofanatase(5299ev)indicating thatmesoporousstructurehas someinfluenceonmicroarea stru ctureof atomom esoporousstru cture formedunderultrasonicirradiation inducedthe changeof atomarrangement，along withstructure rebuildingphenomenon amongmolecules，resulting inthe discriminationofmicroarea inforrnation0fti ando fig4tem micrographs(a)and sadpatterns(b)for mesoporoustio2(sample a)j童兽磐fig5the bindingenergyofoforoti(a)andtifortio(b)(sample a14conclusions anatasemesoporoustitaniawith surfacearea ashigh as140mg waspreparedbythehydrolysisandcondensationof industrialtioso4solution viaposite templateroute underpotentialoutfield，suchasultrasonic，microwave andhydrothermal effectby controllingthephvalueofthereactingsystem，the precursorofmesoporoustitania wasobtained throughsupramolecular selassembly mechanismm esoporoustio2waspreparedbycalcinationto removethetemplateultrasonic wave，microwave andhydrothermalconditionwere adaptivetopreparemesoporoustitania，the formertwo promoteforming bettermesoporousstru cturem icrowavecan notonly strengthenthe actionbetween inorganictitania andsurfactants，but alsoaelerate condensationand crystallizationrateoftitania，resulting instabilizing themesoporousstructureexternal field withenhancing polarefectandsoft hydrothermaleffect ispromisingtopreparemesoporoustitaniathis opensa newway forpreparingporousmaterialsand moredetailed workare undergoingr eferences【1】kresge c丁leonowicz me，roth wj el a1nature fj，1992，359 (6397)710【21Beck JS，Vartuli JC，Roth WJ eta1JAm ChemSocJ，1992，114(27110834【3】Mark EDavisNatureJ，xx，417 (6891)813【4】Hoffmann MR，Martin ST et a1Chem Rev【J】，1995，95 (1)69【5】Puzenat E，Pichat PJ PhotochemPhotobiol J】，xx，160(1-2)127【6】Feringa BL，H