CeO 2yog ib qho tseem ceeb ntawm cov ntaub ntawv tsis tshua muaj hauv ntiaj teb. Covrare ntiaj teb element ceriummuaj ib qho tshwj xeeb sab nrauv hluav taws xob qauv - 4f15d16s2. Nws tshwj xeeb 4f txheej tuaj yeem khaws thiab tso tawm cov khoom siv hluav taws xob zoo, ua rau cerium ions coj tus cwj pwm hauv lub xeev + 3 valence thiab + 4 valence xeev. Yog li, CeO2 cov ntaub ntawv muaj cov pa oxygen ntau dua, thiab muaj peev xwm khaws cia thiab tso tawm cov pa oxygen. Kev sib hloov pauv ntawm Ce (III) thiab Ce (IV) kuj tso cai rau CeO2 cov ntaub ntawv uas muaj peev xwm oxidation-txo catalytic. Piv nrog rau cov ntaub ntawv loj, nano CeO2, raws li hom tshiab ntawm cov khoom siv tsis zoo, tau txais kev saib xyuas thoob plaws vim nws qhov tshwj xeeb saum npoo av, zoo heev oxygen cia thiab tso tawm muaj peev xwm, oxygen ion conductivity, redox kev ua tau zoo, thiab kub ceev ceev oxygen vacancy diffusion. muaj peev xwm. Tam sim no muaj ntau cov ntaub ntawv tshawb fawb thiab cov ntaub ntawv ntsig txog siv nano CeO2 ua catalysts, catalyst carriers lossis additives, active Cheebtsam, thiab adsorbents.
1. Kev npaj ntawm nanometercerium oxide
Tam sim no, cov txheej txheem kev npaj ntau rau nano ceria feem ntau suav nrog cov txheej txheem tshuaj thiab lub cev. Raws li cov txheej txheem tshuaj sib txawv, cov txheej txheem tshuaj tuaj yeem muab faib ua cov txheej txheem nag lossis daus, txoj kev hydrothermal, solvothermal method, sol gel method, microemulsion method thiab electrodeposition method; Txoj kev siv lub cev feem ntau yog txoj kev sib tsoo.
1.1 Txoj kev sib tsoo
Txoj kev sib tsoo rau kev npaj nano ceria feem ntau siv cov xuab zeb sib tsoo, uas muaj qhov zoo ntawm tus nqi qis, ib puag ncig tus phooj ywg, kev ua haujlwm ceev ceev, thiab muaj peev xwm ua tau zoo. Tam sim no nws yog txoj kev ua haujlwm tseem ceeb tshaj plaws hauv kev lag luam nano ceria. Piv txwv li, kev npaj ntawm nano cerium oxide polishing hmoov feem ntau txais kev sib xyaw ua ke ntawm calcination thiab xuab zeb sib tsoo, thiab cov ntaub ntawv raw ntawm cerium raws li denitration catalysts kuj tov rau kev kho ua ntej lossis kho tom qab calcination siv xuab zeb sib tsoo. Los ntawm kev siv sib txawv particle loj xuab zeb sib tsoo hlaws sib piv, nano ceria nrog D50 xws li kaum mus rau pua pua nanometers tuaj yeem tau txais los ntawm kev hloov kho.
1.2 Txoj kev los nag
Txoj kev nag lossis daus yog hais txog cov txheej txheem ntawm kev npaj cov hmoov av los ntawm nag lossis daus, sib cais, ntxuav, ziab, thiab calcination ntawm raw cov ntaub ntawv yaj hauv cov kuab tshuaj tsim nyog. Txoj kev los nag yog siv dav hauv kev npaj cov av tsis tshua muaj thiab doped nanomaterials, nrog rau qhov zoo xws li cov txheej txheem kev npaj yooj yim, kev ua haujlwm siab, thiab tus nqi qis. Nws yog ib txoj hauv kev siv los npaj nano ceria thiab nws cov ntaub ntawv sib xyaw hauv kev lag luam. Txoj kev no tuaj yeem npaj nano ceria nrog txawv morphology thiab particle loj los ntawm kev hloov cov nag lossis daus kub, cov khoom siv concentration, pH nqi, nag lossis daus ceev, nplawm ceev, template, thiab lwm yam. Cov txheej txheem feem ntau cia siab rau nag lossis daus ntawm cerium ions los ntawm ammonia generated los ntawm urea decomposition, thiab kev npaj ntawm nano ceria microspheres yog tswj los ntawm citrate ions. Xwb, cerium ions tuaj yeem ua los ntawm OH - tsim los ntawm hydrolysis ntawm sodium citrate, thiab tom qab ntawd incubated thiab calcined los npaj flake zoo li nano ceria microspheres.
1.3 Hydrothermal thiab solvothermal txoj kev
Ob txoj kev no hais txog cov txheej txheem ntawm kev npaj cov khoom los ntawm kev kub siab thiab kev kub ntxhov siab ntawm qhov ntsuas kub tseem ceeb hauv lub kaw lus kaw. Thaum cov tshuaj tiv thaiv hnyav yog dej, nws hu ua hydrothermal method. Ua ke, thaum cov tshuaj tiv thaiv hnyav yog cov kuab tshuaj organic, nws hu ua solvothermal method. Cov synthesized nano hais muaj siab purity, zoo dispersion thiab niaj hnub hais, tshwj xeeb tshaj yog cov nano hmoov nrog txawv morphologies los yog nthuav tshwj xeeb siv lead ua ntsej muag. Dissolve cerium chloride hauv dej distilled, do thiab ntxiv sodium hydroxide tov. React hydrothermal ntawm 170 ℃ rau 12 teev los npaj cov cerium oxide nanorods nrog rau (111) thiab (110) siv lead ua dav hlau. Los ntawm kev kho cov tshuaj tiv thaiv, qhov kev faib ua feem ntawm (110) siv lead ua dav hlau nyob rau hauv cov dav hlau siv lead ua tuaj yeem nce ntxiv, ntxiv dag zog rau lawv cov kev ua haujlwm catalytic. Kho cov tshuaj tiv thaiv cov kuab tshuaj thiab cov ligands nto tuaj yeem tsim cov nano ceria hais nrog tshwj xeeb hydrophilicity lossis lipophilicity. Piv txwv li, ntxiv acetate ions mus rau theem aqueous tuaj yeem npaj monodisperse hydrophilic cerium oxide nanoparticles hauv dej. Los ntawm kev xaiv cov kuab tshuaj uas tsis yog-polar thiab qhia oleic acid raws li ligand thaum lub sij hawm cov tshuaj tiv thaiv, monodisperse lipophilic ceria nanoparticles tuaj yeem npaj rau hauv cov kuab tshuaj tsis muaj polar organic. (Saib daim duab 1)
Daim duab 1 Monodisperse spherical nano ceria thiab qws zoo li nano ceria
1.4 Sol gel txoj kev
Txoj kev sol gel yog ib txoj hauv kev uas siv qee qhov los yog ntau lub tebchaw ua ntej, ua cov tshuaj tiv thaiv xws li hydrolysis hauv cov kua theem los ua sol, thiab tom qab ntawd tsim cov gel tom qab laus, thiab thaum kawg qhuav thiab calcines los npaj cov hmoov ultrafine. Txoj kev no yog qhov tshwj xeeb tshaj yog tsim rau kev npaj ntau cov khoom sib xyaw nano ceria composite nanomaterials, xws li cerium hlau, cerium titanium, cerium zirconium thiab lwm yam sib xyaw nano oxides, uas tau tshaj tawm nyob rau hauv ntau daim ntawv qhia.
1.5 Lwm txoj kev
Ntxiv rau cov txheej txheem saum toj no, kuj tseem muaj txoj kev siv tshuaj pleev ib ce, microwave synthesis method, electrodeposition method, plasma nplaim combustion method, ion exchange membrane electrolysis method thiab ntau lwm txoj kev. Cov txheej txheem no muaj qhov tseem ceeb heev rau kev tshawb fawb thiab kev siv nano ceria.
Kev siv 2-nanometer cerium oxide hauv kev kho dej
Cerium yog cov khoom siv ntau tshaj plaws ntawm cov ntsiab lus tsis tshua muaj hauv ntiaj teb, nrog tus nqi qis thiab siv dav. Nanometer ceria thiab nws cov composites tau nyiam ntau yam hauv kev kho dej vim lawv qhov tshwj xeeb ntawm thaj chaw siab, kev ua haujlwm siab catalytic thiab kev ruaj ntseg zoo heev.
2.1 Application ofNano Cerium OxideHauv Kev Kho Dej los ntawm Txoj Kev Adsorption
Nyob rau hauv xyoo tas los no, nrog rau kev txhim kho ntawm kev lag luam xws li kev lag luam hluav taws xob, ntau cov dej khib nyiab uas muaj cov pa phem xws li cov hlau hnyav ions thiab fluorine ions raug tso tawm. Txawm tias nyob rau hauv ib txoj kab ntau, nws tuaj yeem ua rau muaj kev puas tsuaj loj rau cov kab mob hauv dej thiab tib neeg nyob ib puag ncig. Cov kev siv feem ntau suav nrog oxidation, flotation, thim rov qab osmosis, adsorption, nanofiltration, biosorption, thiab lwm yam. Ntawm lawv, adsorption technology feem ntau tau txais vim nws txoj haujlwm yooj yim, tus nqi qis, thiab kev kho mob siab. Nano CeO2 cov ntaub ntawv muaj qhov tshwj xeeb saum npoo av thiab qhov ua haujlwm siab saum npoo raws li adsorbents, thiab tau muaj ntau cov ntaub ntawv qhia txog kev sib xyaw ntawm cov ntxeem tau nano CeO2 thiab nws cov ntaub ntawv sib xyaw nrog cov morphologies sib txawv rau adsorb thiab tshem tawm cov teeb meem ions los ntawm dej.
Kev tshawb fawb tau pom tias nano ceria muaj zog adsorption muaj peev xwm rau F - nyob rau hauv dej nyob rau hauv tsis muaj zog acidic tej yam kev mob. Hauv kev daws nrog qhov pib concentration ntawm F - ntawm 100mg / L thiab pH = 5-6, lub peev xwm adsorption rau F - yog 23mg / g, thiab qhov tshem tawm ntawm F - yog 85.6%. Tom qab thauj nws mus rau lub pob polyacrylic acid resin pob (loading npaum li cas: 0.25g / g), lub peev xwm tshem tawm ntawm F - tuaj yeem ncav cuag ntau dua 99% thaum kho qhov sib npaug ntawm 100mg / L ntawm F - aqueous tov; Thaum ua tiav 120 npaug ntawm qhov ntim, ntau dua 90% ntawm F - tuaj yeem raug tshem tawm. Thaum siv los adsorb phosphate thiab iodate, lub peev xwm adsorption tuaj yeem ncav cuag ntau dua 100mg / g nyob rau hauv lub xeev zoo tshaj plaws adsorption. Cov khoom siv tuaj yeem rov qab siv dua tom qab desorption yooj yim thiab kev kho nruab nrab, uas muaj txiaj ntsig zoo rau kev lag luam.
Muaj ntau cov kev tshawb fawb txog kev adsorption thiab kev kho mob hnyav hlau xws li arsenic, chromium, cadmium, thiab txhuas siv nano ceria thiab nws cov ntaub ntawv sib xyaw. Qhov zoo tshaj plaws adsorption pH sib txawv rau cov hlau hnyav ions nrog ntau lub xeev valence. Piv txwv li, qhov tsis muaj zog alkaline nrog kev tsis sib haum xeeb muaj qhov zoo tshaj plaws adsorption xeev rau As (III), thaum qhov zoo tshaj plaws adsorption xeev rau As (V) tau ua tiav nyob rau hauv tsis muaj zog acidic tej yam kev mob, qhov twg lub adsorption muaj peev xwm ncav cuag tshaj 110mg / g nyob rau hauv ob qho tib si. tej yam kev mob. Zuag qhia tag nrho, optimized synthesis ntawm nano ceria thiab nws composite cov ntaub ntawv muaj peev xwm ua tau siab adsorption thiab tshem tawm tus nqi rau ntau yam hnyav hlau ions tshaj pH ntau.
Ntawm qhov tod tes, cerium oxide raws li nanomaterials kuj muaj kev ua tau zoo hauv adsorbing organics hauv dej khib nyiab, xws li kua qaub txiv kab ntxwv, rhodamine B, Congo liab, thiab lwm yam. Piv txwv li, nyob rau hauv cov ntaub ntawv uas twb muaj lawm, nano ceria porous spheres npaj los ntawm electrochemical txoj kev muaj siab. Lub peev xwm adsorption nyob rau hauv kev tshem tawm cov organic dyes, tshwj xeeb tshaj yog nyob rau hauv kev tshem tawm ntawm Congo liab, nrog ib tug adsorption muaj peev xwm ntawm 942.7mg / g nyob rau hauv 60 feeb.
2.2 Daim ntawv thov ntawm nano ceria hauv Advanced oxidation txheej txheem
Advanced oxidation txheej txheem (AOPs luv luv) yog npaj los txhim kho cov txheej txheem kev kho dej uas twb muaj lawm. Advanced oxidation txheej txheem, tseem hu ua kev sib sib zog nqus oxidation technology, yog tus yam ntxwv ntawm zus tau tej cov hydroxyl radical (· OH), superoxide radical (· O2 -), singlet oxygen, thiab lwm yam nrog muaj zog oxidation muaj peev xwm. Nyob rau hauv cov tshuaj tiv thaiv ntawm kub thiab siab, hluav taws xob, suab, lub teeb irradiation, catalyst, thiab lwm yam. Raws li kev sib txawv ntawm generating dawb radicals thiab cov tshuaj tiv thaiv tej yam kev mob, lawv yuav muab faib ua photochemical oxidation, catalytic ntub oxidation, sonochemistry oxidation, ozone. oxidation, electrochemical oxidation, Fenton oxidation, thiab lwm yam (saib daim duab 2).
Daim duab 2 Kev faib tawm thiab thev naus laus zis sib xyaw ua ke ntawm cov txheej txheem oxidation Advanced
Nano ceriayog ib tug heterogeneous catalyst feem ntau siv nyob rau hauv Advanced oxidation txheej txheem. Vim tias qhov hloov pauv sai ntawm Ce3 + thiab Ce4 + thiab cov nyhuv oxidation-txo kom nrawm los ntawm oxygen nqus thiab tso tawm, nano ceria muaj peev xwm catalytic zoo. Thaum siv los ua tus txhawb nqa catalyst, nws tuaj yeem txhim kho catalytic muaj peev xwm thiab ruaj khov. Thaum nano ceria thiab nws cov ntaub ntawv sib xyaw yog siv los ua cov khoom siv catalysts, cov khoom catalytic sib txawv heev nrog cov morphology, particle loj, thiab raug siv lead ua dav hlau, uas yog qhov tseem ceeb cuam tshuam rau lawv cov kev ua tau zoo thiab kev siv. Nws feem ntau ntseeg tias qhov me me thiab qhov loj ntawm qhov chaw tshwj xeeb, qhov chaw sib txuam ntau dua, thiab qhov muaj peev xwm catalytic muaj zog dua. Lub peev xwm catalytic ntawm cov khoom siv lead ua, los ntawm qhov muaj zog mus rau qhov tsis muaj zog, yog nyob rau hauv qhov kev txiav txim ntawm (100) siv lead ua nto> (110) siv lead ua nto> (111) siv lead ua nto, thiab kev ruaj ntseg zoo sib xws.
Cerium oxide yog cov khoom siv semiconductor. Thaum nanometer cerium oxide yog irradiated los ntawm photons nrog lub zog siab tshaj qhov sib txawv band, lub valence band electrons zoo siab heev, thiab cov kev hloov pauv kev coj cwj pwm tshwm sim. Tus cwj pwm no yuav txhawb kev hloov pauv ntawm Ce3 + thiab Ce4 +, ua rau muaj zog photocatalytic kev ua ntawm nano ceria. Photocatalysis tuaj yeem ua tiav ncaj qha degradation ntawm cov organic teeb meem yam tsis muaj cov pa phem thib ob, yog li nws daim ntawv thov yog qhov kev kawm siv thev naus laus zis tshaj plaws hauv kev ua haujlwm ntawm nano ceria hauv AOPs. Tam sim no, lub hom phiaj tseem ceeb yog nyob rau hauv kev kho catalytic degradation ntawm azo dyes, phenol, chlorobenzene, thiab cov dej khib nyiab siv cov catalysts nrog txawv morphologies thiab composite compositions. Raws li tsab ntawv ceeb toom, nyob rau hauv cov txheej txheem optimized catalyst synthesis thiab catalytic qauv, lub peev xwm degradation ntawm cov tshuaj no feem ntau ncav cuag ntau tshaj 80%, thiab lub peev xwm tshem tawm tag nrho cov organic carbon (TOC) tuaj yeem ncav cuag ntau dua 40%.
Nano cerium oxide catalysis rau kev degradation ntawm cov pa phem xws li ozone thiab hydrogen peroxide yog lwm cov cuab yeej kawm dav dav. Zoo ib yam li photocatalysis, nws tseem tsom rau lub peev xwm ntawm nano ceria nrog cov morphologies sib txawv lossis cov dav hlau siv lead ua thiab sib txawv cerium raws li kev sib xyaw catalytic oxidants kom oxidize thiab degrade organic pollutants. Nyob rau hauv cov kev tshwm sim zoo li no, catalysts tuaj yeem ua rau muaj ntau tus neeg muaj zog radicals los ntawm ozone lossis hydrogen peroxide, uas tawm tsam cov kuab paug organic thiab ua kom muaj peev xwm oxidative degradation ntau dua. Vim muaj kev qhia txog oxidants nyob rau hauv cov tshuaj tiv thaiv, lub peev xwm tshem tawm cov organic tebchaw yog heev txhim khu kev qha. Hauv feem ntau cov tshuaj tiv thaiv, qhov kawg tshem tawm tus nqi ntawm lub hom phiaj tuaj yeem ncav cuag lossis mus txog 100%, thiab TOC tshem tawm tus nqi kuj siab dua.
Nyob rau hauv txoj kev electrocatalytic advanced oxidation, cov khoom ntawm cov khoom siv anode nrog siab oxygen evolution overpotential txiav txim siab xaiv ntawm electrocatalytic advanced oxidation txoj kev kho cov organic pollutants. Cov khoom siv cathode yog ib qho tseem ceeb uas txiav txim siab qhov tsim ntawm H2O2, thiab cov khoom ntawm H2O2 txiav txim siab qhov ua tau zoo ntawm electrocatalytic advanced oxidation txoj kev kho cov organic pollutants. Txoj kev tshawb fawb ntawm cov khoom siv hluav taws xob hloov pauv siv nano ceria tau txais kev saib xyuas thoob plaws hauv tebchaws thiab thoob ntiaj teb. Cov kws tshawb fawb feem ntau qhia txog nano cerium oxide thiab nws cov ntaub ntawv sib xyaw los ntawm cov txheej txheem tshuaj sib txawv los hloov cov khoom siv hluav taws xob sib txawv, txhim kho lawv cov kev ua haujlwm ntawm electrochemical, thiab yog li ua kom muaj zog electrocatalytic thiab qhov kawg tshem tawm.
Microwave thiab ultrasound feem ntau tseem ceeb pab ntsuas rau cov qauv catalytic saum toj no. Kev pabcuam ultrasonic ua piv txwv, siv lub suab vibration nrog cov zaus siab dua 25kHz ib ob, ntau lab ntawm cov npuas me me yog tsim nyob rau hauv cov tshuaj formulated nrog ib tug tshwj xeeb tsim tshuaj ntxuav. Cov npuas me me no, thaum lub sij hawm nrawm nrawm thiab nthuav dav, tsis tu ncua ua npuas implosion, tso cai rau cov ntaub ntawv pauv sai sai thiab nthuav dav ntawm cov catalyst nto, feem ntau exponentially txhim kho catalytic efficiency.
3 Kev xaus
Nano ceria thiab nws cov ntaub ntawv sib xyaw tuaj yeem kho tau zoo ions thiab cov kuab paug hauv dej, thiab muaj peev xwm siv tau tseem ceeb hauv kev kho dej yav tom ntej. Txawm li cas los xij, feem ntau cov kev tshawb fawb tseem nyob rau hauv chav kuaj, thiab txhawm rau ua kom tiav daim ntawv thov sai hauv kev kho dej yav tom ntej, cov teeb meem hauv qab no tseem yuav tsum tau kho sai:
(1) Tus nqi npaj siab ntawm nanoCeO 2raws li cov ntaub ntawv tseem yog ib qho tseem ceeb ntawm feem ntau ntawm lawv cov kev siv hauv kev kho dej, uas tseem nyob rau hauv kev tshawb fawb theem. Kev tshawb nrhiav tus nqi qis, yooj yim thiab siv tau zoo uas tuaj yeem tswj cov morphology thiab qhov loj ntawm nano CeO2 raws li cov ntaub ntawv tseem yog qhov tseem ceeb ntawm kev tshawb fawb.
(2) Vim yog qhov me me me me ntawm nano CeO2 cov ntaub ntawv raws li cov khoom siv, cov teeb meem rov ua dua tshiab thiab rov tsim dua tshiab tom qab siv kuj tseem yog yam tseem ceeb uas txwv tsis pub siv lawv daim ntawv thov. Kev sib xyaw ntawm nws nrog cov ntaub ntawv cob lossis cov khoom sib nqus yuav yog ib qho kev tshawb fawb tseem ceeb rau nws cov khoom npaj thiab siv tshuab siv dua tshiab.
(3) Kev txhim kho ntawm cov txheej txheem sib koom ua ke ntawm nano CeO2 raws li cov khoom siv kho dej siv thev naus laus zis thiab cov cuab yeej siv dej phwj tuaj yuav txhawb nqa kev siv nano CeO2 raws li cov khoom siv catalytic hauv kev kho dej.
(4) tseem tsis tau muaj kev tshawb fawb txog cov tshuaj toxicity ntawm nano CeO2 raws li cov ntaub ntawv, thiab lawv ib puag ncig tus cwj pwm thiab toxicity mechanism hauv kev kho dej tsis tau txiav txim siab. Cov txheej txheem dej phwj tiag tiag feem ntau cuam tshuam nrog kev sib koom ua ke ntawm ntau yam kuab paug, thiab cov pa phem sib xyaw ua ke yuav cuam tshuam nrog ib leeg, yog li hloov cov yam ntxwv saum npoo thiab muaj peev xwm toxicity ntawm nanomaterials. Yog li ntawd, nws yog ib qho tseem ceeb uas yuav tsum tau ua kom muaj kev tshawb fawb ntxiv txog kev cuam tshuam.
Post lub sij hawm: May-22-2023