CN103087716A

CN103087716A - Synthesis method of rare earth doped hexagonal-phase cerium sodium fluoride nanocrystalline

Info

Publication number: CN103087716A
Application number: CN2013100263464A
Authority: CN
Inventors: 刘丽琴; 陈学元; 涂大涛; 刘永升; 朱浩淼
Original assignee: Fujian Institute of Research on the Structure of Matter of CAS
Current assignee: Fujian Institute of Research on the Structure of Matter of CAS
Priority date: 2013-01-21
Filing date: 2013-01-21
Publication date: 2013-05-08

Abstract

The invention provides a synthesis method of rare earth doped hexagonal-phase cerium sodium fluoride nanocrystalline. The synthesis method comprises the following steps of: using oleic acid and octadecene as solvents, mixing the cerium chloride and rare-earth chloride under the atmosphere of nitrogen, maintaining the temperature at 120-160 DEG C, stirring for a certain peroid of time, cooling the mixture to the room temperature, adding a methanol solution containing sodium hydroxide and ammonium fluoride to the cooled mixture, stirring for a certain peroid of time, heating the stirred mixture under the atmosphere of nitrogen so as to remove methanol, heating to 250-320 DEG C under the atmosphere of nitrogen to react for a certain peroid of time, cooling to room temperature, carrying out centrifugal separation to obtain a reactant, and washing and drying the reactant to obtain the rare earth doped hexagonal-phase cerium sodium fluoride nanocrystalline. The rare earth doped hexagonal-phase cerium sodium fluoride nanocrystalline prepared by using the synthesis method is better in uniform dispersity and excellent in down-conversion and up-conversion luminescence properties.

Description

The synthetic method of rear-earth-doped six side's phase fluorination cerium natrium nanocrystallines

Technical field

The present invention relates to a kind of method of synthetic rare earth doped inorganic nano-crystal, especially relate to a kind of method of synthetic rare earth doped six side's phase fluorination cerium natrium nanocrystallines.

Background technology

Rear-earth-doped inorganic nano-crystal has wide purposes in fields such as green illumination light source, nano photoelectronic devices, flat pannel display, biomarkers owing to having the comprehensive advantages such as high photochemical stability, narrow emission live width, long fluorescence lifetime, high-luminous-efficiency, almost non-toxic property and tunable fluorescent emission wavelength in over half a century in the past.Along with the appearance of the fast development of nanotechnology, particularly novel material and novel synthesis, people are more and more denseer to the interest of rare earth mixing with nano luminescent material.

In recent years, lot of documents has been reported the synthetic of the nano materials such as rear-earth-doped oxide compound, phosphoric acid salt, vanadate and fluorochemical and spectrum property research, particularly fluorochemical has than low phonon energy as a class, stablize the luminous host of physicochemical property and be subject to people's favor, wherein rare earth doped cerium fluoride sodium (NaCeF ₄) nano material is due to the limitation of synthesizing mean, research is less at present.It should be noted that Ce ³⁺Ion can be used as that sensitized ions absorbs ultraviolet photon and by transmission ofenergy and then activate other rare earth ions (as Eu ³⁺, Tb ³⁺And Dy ³⁺Deng), thereby can realize conversion luminescence under the polychrome of single wavelength under exciting; In addition, Ce ³⁺It is near-infrared luminous (as Er that unique level structure also is conducive to produce stronger upper conversion ³⁺, Tm ³⁺And Ho ³⁺Deng), these characteristics show rear-earth-doped NaCeF ₄Nano material has important researching value and practical prospect.Recently, the seminar such as Jeong and Li Yadong has reported respectively to synthesize by solvent-thermal method and has obtained rear-earth-doped NaCeF ₄Nanocrystalline, but the solvent-thermal method reaction times grow (being generally 24 hours), power consumption is higher thus, not only size is larger by the resulting particle of the method, and easily reunites, these factors have all limited rear-earth-doped NaCeF ₄Nano material further developing and using (reference: Jeong et al., Controlled Fabrication and Shape-Dependent Luminescence Properties of Hexagonal NaCeF ₄, NaCeF ₄: Tb ³⁺Nanorods via Polyol-Mediated Solvothermal Route. Inorganic Chemistry, 2011,50,3387-3393; Li et al., Nucleation and Growth of CeF ₃And NaCeF ₄Nanocrystals. Chemistry-a European Journal, 2009,15,2512-2517).For above problem, the present invention adopts coprecipitation method to synthesize rear-earth-doped six side's phase NaCeF take oleic acid and octadecylene as reaction solvent ₄Nanocrystalline.This method is the reaction times shorter (in a few hours) not only, and can synthesize and obtain homodisperse nano particle, by the different rare earth ion that adulterates, the utilizing emitted light that can regulate nano particle from ultraviolet, can see near infrared, thereby be with a wide range of applications in fields such as flat pannel display and biomarkers.

Summary of the invention

The object of the invention is to synthetic homodisperse rear-earth-doped six side's phase fluorination cerium sodium nano materials.

The present invention adopts following technical scheme: the component of the nano material that the present invention is prepared is xLn ³⁺-(1-x) NaCeF ₄, 0＜x＜=50 mol%, wherein Ln ³⁺Be selected from Er ³⁺, Ce ³⁺, Eu ³⁺, Yb ³⁺, Gd ³⁺, Tm ³⁺, Ho ³⁺, Tb ³⁺, Nd ³⁺, Pr ³⁺, Dy ³⁺And Sm ³⁺In one or both.

The preparation method of rear-earth-doped six side's phase fluorination cerium natrium nanocrystallines comprises the steps: at first to take Cerium II Chloride and rare earth chloride and is dissolved in the mixed solvent of oleic acid and octadecylene, then at N ₂Under atmosphere, heated and stirred is cooled to room temperature after for some time; Take in addition Neutral ammonium fluoride and sodium hydroxide and be dissolved in methyl alcohol, stirring is added drop-wise in mentioned solution after making it form settled solution, heats to get rid of methyl alcohol under the atmosphere of nitrogen after stirring for some time, then is warming up to certain temperature and is incubated for some time; Be cooled to room temperature, white precipitate occurs, centrifugal with supernatant liquid and precipitate and separate, with the washing of precipitate that obtains repeatedly with the by product except dereaction; Can obtain rear-earth-doped six side's phase fluorination cerium natrium nanocrystallines after last vacuum-drying.

Rear-earth-doped six side's phase NaCeF ₄Nanocrystalline sign.Detect by X-ray powder diffraction (XRD) and show the NaCeF for preparing ₄Nano particle is pure six side's phase structures.Transmission electron microscope (TEM) test shows that what obtain is the homodisperse nano particle of 100 nm left and right, and its selected area electron diffraction (SEAD) pattern has presented the electron diffraction point that rule is arranged, and shows that the particle that obtains is single crystal samples.The NaCeF of doping with rare-earth ions not ₄Nanocrystalline, its excitation spectrum exists at 225-275 nm place and significantly excites wide bag, and its emission spectrum is observed stronger emission band at 275-375 nm place, and the excitation peak that these are wider and emission peak are by Ce ³⁺4f-5d between transition of electron cause.

After doping with rare-earth ions, utilize Ce ³⁺Transition of electron between the 4f → 5d of ion can realize the transmission ofenergy from matrix to the rare earth ion, and then realizes conversion luminescence under the polychrome of single wavelength under exciting; For example at Eu ³⁺, Tb ³⁺And Dy ³⁺The ion list is mixed NaCeF ₄In nanocrystalline excitation spectrum, we have observed Ce ³⁺4f → 5d transition peak, excite by 252.6 nm, can realize respectively Eu ³⁺, Tb ³⁺And Dy ³⁺Characteristic emission.In addition, Ce ³⁺ ²F _5/2With ²F _7/2Energy level spacing only has ~ 2100 cm ^-1, therefore can be used as the quencher of some doping with rare-earth ions high-energy energy level, be conducive to produce stronger upper conversion near-infrared luminous, for example pass through Yb ³⁺With Er ³⁺, Tm ³⁺Or Ho ³⁺Deng codoped, under 980 nm excite, we observed respectively be positioned at ~ 1500,800,1200 nm near stronger upper switching emission.

The rear-earth-doped six side's phase NaCeF that synthesize by the present invention ₄Nano material, preparation process is simple, synthesis condition is easily controlled, good reproducibility.Utilize the rare earth ion of doping can obtain good upper conversion or lower conversion luminescence performance, therefore in fields such as lighting source and bioanalysiss, application potential is preferably arranged.

Description of drawings

Accompanying drawing 1:NaCeF ₄: Dy ³⁺Nanocrystalline X-ray powder diffraction figure.The instrument model is MiniFlex2, and producer is Rigaku, and copper target emanation wavelength is λ=0.154187 nm.

Accompanying drawing 2:NaCeF ₄: Dy ³⁺Nanocrystalline transmission electron microscope picture, illustration are nanocrystalline selected area electron diffraction pattern.The instrument model is JEM-2010, and producer is JEOL.

Accompanying drawing 3:NaCeF ₄Nanocrystalline room temperature excitation spectrum and emission spectrum.The instrument model is FLS920, and producer is Edinburgh, and excitation light source is xenon lamp.

Accompanying drawing 4: at NaCeF ₄In nanocrystalline, Ce ³⁺Ion sensitized Eu ³⁺, Tb ³⁺And Dy ³⁺The energy level schematic diagram of ion.

Accompanying drawing 5: under room temperature, Eu ³⁺, Tb ³⁺And Dy ³⁺The ion list is mixed NaCeF ₄Nanocrystalline excitation spectrum (left side) and emission spectrum (right side), doping content is 5 mol%.The instrument model is FLS920, and producer is Edinburgh, and excitation light source is xenon lamp.In excitation spectrum, Eu ³⁺, Tb ³⁺, and Dy ³⁺The monitoring wavelength of ion is respectively 616.6 542.8 and 572.3 nm; And in emission spectrum, excitation wavelength is 252.6 nm.

Accompanying drawing 6: at Er ³⁺, Tm ³⁺Or Ho ³⁺Ion and Yb ³⁺Ion is mixed NaCeF altogether ₄In nanocrystalline, 980 nm excite down, Er ³⁺, Tm ³⁺And Ho ³⁺The energy level schematic diagram of ion.

Accompanying drawing 7: under room temperature, Er ³⁺, Tm ³⁺Or Ho ³⁺Ion and Yb ³⁺Ion is mixed NaCeF altogether ₄Nanocrystalline emission spectrum, wherein, Yb ³⁺Ion doping concentration is 20 mol%, Er ³⁺, Tm ³⁺Or Ho ³⁺The doping content of ion is respectively 2,1,2 mol%; The instrument model is FSP920-C, and producer is Edinburgh, and excitation light source is the 980-nm semiconductor laser.

Embodiment

Rare earth doped cerium fluoride sodium preparations of nanomaterials method provided by the present invention, its substantive features can further be embodied by following examples.

Example 1:NaCeF ₄: at first the preparation that 0.02Eu is nanocrystalline takes 0.348 g CeCl ₃6H ₂O and 0.007 g EuCl ₃6H ₂O is dissolved in the mixed solvent of 4 mL oleic acid and 16 mL octadecylenes, then at N ₂Be heated to 160 ° of C under atmosphere, stirring is cooled to room temperature after making it form settled solution; Take in addition 0.148 g NH ₄F and 0.1 g NaOH are dissolved in 10 mL methyl alcohol, and stirring is added drop-wise in mentioned solution after making it form settled solution, at room temperature continue to stir 30 min; Then at N ₂Under atmosphere, heated solution to 60 ° C is to get rid of methyl alcohol, and then the heat-up rate with 10-15 ° of C/min is heated to 300 ° of C, insulation 1 h; Be cooled to room temperature, white precipitate occurs, centrifugal with supernatant liquid and precipitate and separate, the precipitation that obtains is used hexanaphthene and absolute ethanol washing repeatedly, with the by product except dereaction; To be deposited in vacuum-drying under 50 ° of C, namely obtain six side's phase NaCeF ₄: 0.02Eu is nanocrystalline.

Example 2:NaCeF ₄: at first the preparation that 0.1Dy is nanocrystalline takes 0.319 g CeCl ₃6H ₂O and 0.037 g DyCl ₃6H ₂O is dissolved in the mixed solvent of 5 mL oleic acid and 15 mL octadecylenes, then at N ₂Be heated to 150 ° of C under atmosphere, stirring is cooled to room temperature after making it form settled solution; Take in addition 0.148 g NH ₄F and 0.1 g NaOH are dissolved in 10 mL methyl alcohol, and stirring is added drop-wise in mentioned solution after making it form settled solution, at room temperature continue to stir 30 min; Then at N ₂Under atmosphere, heated solution to 60 ° C is to get rid of methyl alcohol, and then the heat-up rate with 10-15 ° of C/min is heated to 310 ° of C, insulation 0.5 h; Be cooled to room temperature, white precipitate occurs, centrifugal with supernatant liquid and precipitate and separate, the precipitation that obtains is used hexanaphthene and absolute ethanol washing repeatedly, with the by product except dereaction; To be deposited in vacuum-drying under 50 ° of C, namely obtain six side's phase NaCeF ₄: 0.1Dy is nanocrystalline.

Example 3:NaCeF ₄: at first the preparation that 0.05Tb is nanocrystalline takes 0.337 g CeCl ₃6H ₂O and 0.019 g TbCl ₃6H ₂O is dissolved in the mixed solvent of 6 mL oleic acid and 14 mL octadecylenes, then at N ₂Be heated to 120 ° of C under atmosphere, stirring is cooled to room temperature after making it form settled solution; Take in addition 0.148 g NH ₄F and 0.1 g NaOH are dissolved in 10 mL methyl alcohol, and stirring is added drop-wise in mentioned solution after making it form settled solution, at room temperature continue to stir 30 min; Then at N ₂Under atmosphere, heated solution to 60 ° C is to get rid of methyl alcohol, and then the heat-up rate with 10-15 ° of C/min is heated to 290 ° of C, insulation 2 h; Be cooled to room temperature, white precipitate occurs, centrifugal with supernatant liquid and precipitate and separate, the precipitation that obtains is used hexanaphthene and absolute ethanol washing repeatedly, with the by product except dereaction; To be deposited in vacuum-drying under 50 ° of C, namely obtain six side's phase NaCeF ₄: 0.05Tb is nanocrystalline.

Example 4:NaCeF ₄: at first the preparation that 0.02Er/0.18Yb is nanocrystalline takes 0.284 g CeCl ₃6H ₂O, 0.007 g ErCl ₃6H ₂O and 0.07 g YbCl ₃6H ₂O is dissolved in the mixed solvent of 3 mL oleic acid and 17 mL octadecylenes, then at N ₂Be heated to 160 ° of C under atmosphere, stirring is cooled to room temperature after making it form settled solution; Take in addition 0.148 g NH ₄F and 0.1 g NaOH are dissolved in 10 mL methyl alcohol, and stirring is added drop-wise in mentioned solution after making it form settled solution, at room temperature continue to stir 30 min; Then at N ₂Under atmosphere, heated solution to 60 ° C is to get rid of methyl alcohol, and then the heat-up rate with 10-15 ° of C/min is heated to 300 ° of C, insulation 1 h; Be cooled to room temperature, white precipitate occurs, centrifugal with supernatant liquid and precipitate and separate, the precipitation that obtains is used hexanaphthene and absolute ethanol washing repeatedly, with the by product except dereaction; To be deposited in vacuum-drying under 50 ° of C, namely obtain six side's phase NaCeF ₄: 0.02Er/0.18Yb is nanocrystalline.

Example 5:NaCeF ₄: at first the preparation that 0.01Tm/0.29Yb is nanocrystalline takes 0.498 g CeCl ₃6H ₂O, 0.007 g TmCl ₃6H ₂O and 0.225 g YbCl ₃6H ₂O is dissolved in the mixed solvent of 10 mL oleic acid and 30 mL octadecylenes, then at N ₂Be heated to 150 ° of C under atmosphere, stirring is cooled to room temperature after making it form settled solution; Take in addition 0.296 g NH ₄F and 0.2 g NaOH are dissolved in 20 mL methyl alcohol, and stirring is added drop-wise in mentioned solution after making it form settled solution, at room temperature continue to stir 30 min; Then at N ₂Under atmosphere, heated solution to 60 ° C is to get rid of methyl alcohol, and then the heat-up rate with 10-15 ° of C/min is heated to 310 ° of C, insulation 0.5 h; Be cooled to room temperature, white precipitate occurs, centrifugal with supernatant liquid and precipitate and separate, the precipitation that obtains is used hexanaphthene and absolute ethanol washing repeatedly, with the by product except dereaction; To be deposited in vacuum-drying under 50 ° of C, namely obtain six side's phase NaCeF ₄: 0.01Tm/0.29Yb is nanocrystalline.

Example 6:NaCeF ₄: at first the preparation that 0.05Ho/0.15Yb is nanocrystalline takes 0.142 g CeCl ₃6H ₂O, 0.009 g HoCl ₃6H ₂O and 0.029 g YbCl ₃6H ₂O is dissolved in the mixed solvent of 3 mL oleic acid and 7 mL octadecylenes, then at N ₂Be heated to 120 ° of C under atmosphere, stirring is cooled to room temperature after making it form settled solution; Take in addition 0.074 g NH ₄F and 0.05 g NaOH are dissolved in 5 mL methyl alcohol, and stirring is added drop-wise in mentioned solution after making it form settled solution, at room temperature continue to stir 30 min; Then at N ₂Under atmosphere, heated solution to 60 ° C is to get rid of methyl alcohol, and then the heat-up rate with 10-15 ° of C/min is heated to 290 ° of C, insulation 2 h; Be cooled to room temperature, white precipitate occurs, centrifugal with supernatant liquid and precipitate and separate, the precipitation that obtains is used hexanaphthene and absolute ethanol washing repeatedly, with the by product except dereaction; To be deposited in vacuum-drying under 50 ° of C, namely obtain six side's phase NaCeF ₄: 0.05Ho/0.15Yb is nanocrystalline.

Claims

1. the method for synthetic rare earth doped six side's phase fluorination cerium natrium nanocrystallines, it is characterized in that: utilize oleic acid and octadecylene to be solvent, under the atmosphere of nitrogen, Cerium II Chloride and rare earth chloride are mixed, be incubated and stir for some time at 120-160 ° of C, after it is cooled to room temperature, the methanol solution that adds wherein sodium hydroxide and Neutral ammonium fluoride, heat to get rid of methyl alcohol after stirring for some time under the atmosphere of nitrogen, then be warming up to 250-320 ° of C under the atmosphere of nitrogen, be cooled to room temperature after reaction for some time, centrifugation obtains reaction product, can obtain rear-earth-doped six side's phase fluorination cerium natrium nanocrystallines after washing drying.