CN1289630C - Method for preparing manganese-doped zinc silicate green luminescent powder by low temperature solid state reaction - Google Patents
Method for preparing manganese-doped zinc silicate green luminescent powder by low temperature solid state reaction Download PDFInfo
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- CN1289630C CN1289630C CN 200410025310 CN200410025310A CN1289630C CN 1289630 C CN1289630 C CN 1289630C CN 200410025310 CN200410025310 CN 200410025310 CN 200410025310 A CN200410025310 A CN 200410025310A CN 1289630 C CN1289630 C CN 1289630C
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Abstract
The present invention provides a method for preparing manganese-doping zinc silicate green fluorescent powder by means of a low-temperature solid-phase reaction, which belongs to the field of luminescent materials. Mesoporous silicon oxide, a zinc salt and a divalent manganese salt are used as raw materials. Meso-porous silicon oxide which is accurately weighed is dissolved in an alcohol solution of the zinc salt and the divalent manganese salt; after the solution is dried, a mixture of the meso-porous slilicon oxide, the zinc salt and the divalent manganese salt is calcined at 750 to 950 DEG C under the protection of neutral gas, and then, a solid-phase reaction is carried out so as to prepare the manganese-doping zinc silicate green fluorescent powder. The method has the characteristics of low preparation temperature, easy doping, large specific surface area of a product, good fluorescent property, high green purity, adjustable fluorescence decay time, suitability for fluorescent lamps, display boards, cathode ray tubes and medical X-ray radiation detectors, high yield rate, etc.
Description
Technical field
The invention relates to a kind of low-temperature solid phase reaction that utilizes and prepare manganese-doped willemite (Zn
2SiO
4: the Mn) novel method of green emitting phosphor, this green fluorescence powder can be used for colour plasma display board, cathode tube, luminescent lamp, medical X-ray radiation detector.
Background technology
Closely during the last ten years, ordered mesoporous material is owing to have Jie's view hole road structure, high-specific surface area of rule and thermostability and hydrothermal stability preferably, be widely used in characteristics such as catalysis, absorption, a main object assembling, low-dimension nano material and light, electronic devices and components preparation and medicament slow release, and become one of materialogy field research focus rapidly, and caused the extensive concern of other scientific domains such as physics, chemistry, medicine, biology.And on the other hand, in known fluorescent material, manganese-doped willemite (Zn
2SiO
4: Mn) with its brightness height, colour purity is good, fluorescence efficiency is high and thermostability and chemical stability are good and become a kind of good green fluorescent material, and be widely used in cathode tube, luminescent lamp, aspects such as the radiation detector in the medical image system.In recent years, along with the particularly develop rapidly of color plasma flat pannel display (PDP) technology of giant-screen flat panel display, the research of its display material-plasma body fluor has caused people's extensive interest, and Zn
2SiO
4: Mn is exactly wherein the most frequently used a kind of green-emitting phosphor.
Manganese-doped willemite fluorescent material generally can be used chemical general formula: Zn
2-xMn
xSiO
4Represent that wherein x represents the amount of mixing manganese.About Zn
2SiO
4: the Mn preparation method of green emitting phosphor has a lot of bibliographical informations.As: (J.Lumin.1974 8:443-451) proposes with ZnO, MnF A.L.N.Stevels etc.
2Excessive slightly SiO
2High-temperature solid phase reaction method preparation for raw material; (J.Electrochem.Soc.1993 140:2019-2022) proposes with ZnO, SiO A.Morell etc.
2And MnCO
3High-temperature solid phase reaction method preparation for raw material; (J.Mater.Sci.1995 30:2358-2363) has proposed to synthesize with hydrothermal method Q.H.Li etc.; (Inorg.Mater.1996 32:80-84) has proposed the sol-gel method to T.I.Thristov etc.; (J.Electrochem.Soc.1989 136:3532-3535) has proposed to synthesize with coprecipitation method I.F.Chang etc.; (Mater.Res.Bull.1994 29:751-757) has proposed (OC with Si to R.Morimo etc.
2H
5)
4, Zn (NO
3)
2And Mn (NO
3)
2High temperature atomizing decomposition method preparation for raw material.These methods advantage of having nothing in common with each other, but all come with some shortcomings.Have the advantage of low, the easy doping of synthesis temperature, fluorescent powder particle diameter unanimity as low temperature wet methods such as hydrothermal method, sol-gel method, coprecipitation methods, but the degree of crystallinity of prepared fluor is not high, and low-crystallinity will directly influence Zn
2SiO
4: the luminescent properties of Mn green-emitting phosphor and chemical stability thereof, the Cl of small portion of residual
-Ion also can produce considerable influence to the final use properties of fluor, reduces the fluorescent brightness of fluor, reacts not thorough, and stoichiometry ratio, productive rate are not high, residual many amorphous SiO
2, so low temperature wet method can not a kind of at last good method.Though high temperature atomizing decomposition method has the advantage of fluorescent powder particle diameter unanimity equally,, the high-temperature spray process is with O
2Be carrier gas stream, Mn
2+The easy oxidation of ion, powder is easily collecting not, and preparation temperature is not low and equipment requirements is high.
And high-temperature solid phase reaction method have product degree of crystallinity height, technology simple, quick, easily produce in batches etc. a bit, also be the Zn that uses of most widely used general, modal manufacturer at present
2SiO
4: the method for Mn green emitting phosphor, but the preparation temperature height of this method, about 1200 ℃ even higher, sintering easily takes place in prepared fluorescent material, the cluster of grains coalescence is grown up, need pulverize before using, following process such as ball milling and grinding, these processing all can destroy the condition of surface of fluor, and the condition of surface of granular size and fluor plays a decisive role to the fluorescence property of fluorescent material, and macrobead and destructive condition of surface all cause its luminous intensity and fluorescence persistence to reduce significantly, in addition, raw material all mixes with solid form, be not easy to realize that mn ion evenly mixes in zinc silicate matrix, but assemble, easily cause concentration quenching at the crystal boundary place.
Therefore, still lack the effective Zn of a kind of low temperature so far
2SiO
4: Mn is imitated preparation method of green emitting phosphor.
Summary of the invention
The objective of the invention is to a) to have proposed a kind of low-temperature solid phase reaction first and prepare Zn
2SiO
4: the novel method of Mn efficient green fluorescent material; B) adopt method provided by the invention to realize that easily the manganese of different concns mixes; C) adopt the prepared Zn of method provided by the invention
2SiO
4: Mn fluorescent material has characteristics such as degree of crystallinity height, particle is little, specific surface area is big, fluorescence is strong, has application promise in clinical practice.
The concrete enforcement of the present invention is as follows:
1, suspension preparation
Press chemical general formula: Zn
2-xMn
xSiO
4In stoichiometric ratio, accurately take by weighing zinc salt, manganous salt and mesopore silicon oxide.Zinc salt can be a kind of in the oxygen zinc salt of containing that alkoxide of zinc nitrate, zinc nitrite, zinc acetate, zinc etc. is soluble in alcoholic solvent, manganous salt can be manganous acetate, formic acid manganese, manganese naphthenate, six ethanol alkoxide of closing Manganous chloride tetrahydrate and manganese etc. can be dissolved in alcoholic solvent and pyrolytic decomposition the time ionic valence condition constant contain a kind of in the oxygen manganous salt.Zinc salt and manganous salt are dissolved in the alcoholic solvent simultaneously fully, behind the adding mesopore silicon oxide, ultrasonic dispersing, continuously stirring becomes suspension again.Manganese doping x=0.01-0.24, after ultrasonic dispersing, the violent stirring time is 2-10 hour, the suspension preparation temperature is 0-30 ℃.
2, drying
Continuously stirring and air seasoning, drying temperature is 0-30 ℃, the time is for to become mixed powder until the suspension complete drying.
3, heat-treat condition: under the neutral gas protection, 750-950 ℃ of solid state reaction temperature, soaking time 1-6 hour.
Zn provided by the invention
2SiO
4: the characteristics of Mn preparation method of green emitting phosphor are:
A. significantly reduce the solid state reaction temperature, easily mix, and doping content variation range big (1mol%-24mol%).
B. adopt method provided by the invention, prepared Zn
2SiO
4: the degree of crystallinity height of Mn green emitting phosphor, particle is little, and specific surface area obviously increases, and need not follow-up to pulverize, processing treatment such as ball milling and grinding.
C. adopt method provided by the invention, prepared Zn
2SiO
4: the fluorescence intensity height of Mn green emitting phosphor, colourity is pure.
D. the mesoporous silicon oxide raw material prepares easily or buys, and other raw materials obtain easily, and equipment is simple, and the productive rate height is easy to suitability for industrialized production.
Description of drawings
Fig. 1 is embodiment 1-3,5 prepared Zn
2SiO
4: the wide-angle x-ray diffraction figure of Mn green emitting phosphor.This figure explanation adopts method provided by the invention to prepare Zn
2SiO
4: the Mn green emitting phosphor can obtain Zn by solid state reaction than low 750 ℃
2SiO
4Crystal, along with the rising of temperature, speed of response improves rapidly; No matter with zinc acetate or zinc nitrate is zinc salt, under 850 ℃, but through 3 hours equal complete reaction, and obtain single Zn
2SiO
4Crystalline phase.
Fig. 2 is the prepared Zn of embodiment 1-4
2SiO
4: the specific surface area of Mn green emitting phosphor and the prepared Zn of employing conventional high-temperature solid reaction process under 1250 ℃
1.92Mn
0.08SiO
4Fluorescent material (called after RefCSSR).This figure explanation, adopt the prepared product of method provided by the invention to have higher specific surface area, specific surface area descends to some extent although product is with the raising of temperature of reaction, compares with the traditional prepared product of high-temperature solid phase reaction method of employing, and specific surface area is still very high.
Fig. 3 is the prepared Zn of embodiment 3,5
2SiO
4: Mn green emitting phosphor and the prepared Zn of employing conventional high-temperature solid reaction process (CSSR) under 1250 ℃
1.92Mn
0.08SiO
4Fluorescent material (Ref CSSR) the incident wave λ that coexists
ExcFluorescence spectrum figure under=258nm excites.This figure explanation is compared with conventional solid-state method, adopts method provided by the present invention, no matter be to be zinc salt with zinc acetate or zinc nitrate, under 850 ℃, through 3 hours prepared Zn
2SiO
4: the fluorescence intensity of Mn green emitting phosphor is higher, and fluorescence is more near the green glow center; In the duplicate situation of test condition, the raising of fluorescence intensity correspondingly embodies the raising of fluorescence efficiency, and relative fluorescence efficiency is higher.
Fig. 4 is 850 ℃ of prepared Zn with different manganese dopings down
2SiO
4: the fluorescence relative intensity of Mn green emitting phosphor is with the change curve of fall time.This figure explanation, the doping of different manganese concentration, the fluorescence intensity attenuation change speed difference of corresponding product changes the doping of manganese, can regulate the fluorescence decay time of product effectively, to be adapted to various concrete application requiring.
Embodiment
Embodiment 1
Press chemical general formula Zn
2-xMn
xSiO
4The stoichiometric ratio of middle x=0.05 accurately takes by weighing zinc acetate, manganous acetate and SBA-15 mesopore silicon oxide.Under violent stirring, be dissolved in zinc acetate and manganous acetate in the methyl alcohol simultaneously, add the SBA-15 powder, after ultrasonic vibration is disperseed, brute force stirs into suspension, is positioned over then in the stink cupboard, and continuously stirring also feeds the keen draft drying, be transferred in the resistance furnace behind the powder drying, pour nitrogen, 750 ℃ of reactions obtained light yellow powder after 3 hours.Fig. 1 curve a is the wide-angle x-ray diffraction collection of illustrative plates of this product, and the result shows, begins to separate out Zn under this thermal treatment
2SiO
4Crystal, but because reaction not exclusively, still has a large amount of ZnO to exist, the specific surface area that the BET nitrogen adsorption records powder is 17.8697m
2/ g, this product is in wavelength X
ExcTransmitting green light under the ultraviolet excitation of=258nm, but intensity is lower.
Press chemical general formula Zn
2-xMn
xSiO
4The stoichiometric ratio of middle x=0.05 accurately takes by weighing zinc acetate, manganous acetate and SBA-15 mesopore silicon oxide.Under violent stirring, be dissolved in zinc acetate and manganous acetate in the methyl alcohol simultaneously, add the SBA-15 powder, after ultrasonic vibration is disperseed, brute force stirs into suspension, is positioned over then in the stink cupboard, and continuously stirring also feeds the keen draft drying, be transferred in the resistance furnace behind the powder drying, pour nitrogen, 800 ℃ of reactions obtained slightly lurid powder after 3 hours.Fig. 1 curve b is the wide-angle x-ray diffraction collection of illustrative plates of this product, and the result shows, begins to separate out in a large number Zn under this thermal treatment
2SiO
4Crystal, though still have remaining ZnO to exist, amount seldom.The specific surface area that the BET nitrogen adsorption records powder is 11.1720m2/g, and this product is in wavelength X
ExcTransmitting green light under the ultraviolet excitation of=258nm, intensity improves bigger.
Embodiment 3
Press chemical general formula Zn
2-xMn
xSiO
4The stoichiometric ratio of middle x=0.08 accurately takes by weighing zinc acetate, manganous acetate and SBA-15 mesopore silicon oxide.Under violent stirring, be dissolved in zinc acetate and manganous acetate in the methyl alcohol simultaneously, add the SBA-15 powder, after ultrasonic vibration is disperseed, brute force stirs into suspension, is positioned over then in the stink cupboard, and continuously stirring also feeds the keen draft drying, be transferred in the resistance furnace behind the powder drying, pour nitrogen, 850 ℃ of reactions obtained white powder after 3 hours.Fig. 1 curve c is the wide-angle x-ray diffraction collection of illustrative plates of this product, and the result shows that raw material reaction is complete under this thermal treatment, and the diffraction peak energy of diffraction peak and trigonal system willemite is corresponding well, does not have ZnO, SiO
2, MnO and other peak exist, product is the single crystalline phase of manganese-doped willemite.The specific surface area that the BET nitrogen adsorption records powder is 7.0157m
2/ g, Fig. 3 curve a are that this product is in wavelength X
ExcFluorescence spectrum figure under the ultraviolet excitation of=258nm launches very pure green fluorescence, and intensity significantly improves.Under identical preparation, drying conditions and heat-treat condition, change the concentration x=0.02 of manganese, 0.05,0.12, Zhi Bei Zn respectively
2SiO
4: the Mn green emitting phosphor is white, and wavelength X coexists
ExcEqual transmitting green light under the ultraviolet excitation of=258nm, peak position with the increase of manganese concentration red shift (523 → 527nm), intensity increases earlier afterwards falls, and fluorescence intensity is the highest at the x=0.08 place.Their fluorescence intensity attenuation change in time increases with manganese concentration shown in each curve of Fig. 4, and fluorescence decay time shortens.
Press chemical general formula Zn
2-xMn
xSiO
4The stoichiometric ratio of middle x=0.08 accurately takes by weighing zinc acetate, manganous acetate and SBA-15 mesopore silicon oxide.Under violent stirring, be dissolved in zinc acetate and manganous acetate in the methyl alcohol simultaneously, add the SBA-15 powder, after ultrasonic vibration is disperseed, brute force stirs into suspension, is positioned over then in the stink cupboard, and continuously stirring also feeds the keen draft drying, be transferred in the resistance furnace behind the powder drying, pour nitrogen, 950 ℃ of reactions obtained white powder after 5 hours.The wide-angle x-ray diffraction result of this product shows that raw material reaction is complete under this thermal treatment, and the diffraction peak energy of diffraction peak and trigonal system willemite is corresponding well, does not have ZnO, SiO
2, MnO and other peak exist, product is the single crystalline phase of manganese-doped willemite.The specific surface area that the BET nitrogen adsorption records powder is 2.6461m
2/ g obviously reduces, and the beginning sintering is also reunited, and this product is in wavelength X
ExcThe green fluorescence that emission under the ultraviolet excitation of=258nm is stronger.
Embodiment 5
Press chemical general formula Zn
2-xMn
xSiO
4The stoichiometric ratio of middle x=0.08 accurately takes by weighing zinc nitrate, manganous acetate and SBA-15 mesopore silicon oxide.Under violent stirring, be dissolved in zinc nitrate and manganous acetate in the ethanol simultaneously, add the SBA-15 powder, after ultrasonic vibration is disperseed, brute force stirs into suspension, is positioned over then in the stink cupboard, and continuously stirring also feeds the keen draft drying, be transferred in the resistance furnace behind the powder drying, pour nitrogen, 850 ℃ of reactions obtained white powder after 3 hours.Fig. 1 curve d is the wide-angle x-ray diffraction collection of illustrative plates of this product, and the result shows that raw material reaction is complete under this thermal treatment, and the diffraction peak energy of diffraction peak and trigonal system willemite is corresponding well, does not have ZnO, SiO
2, MnO and other peak exist, product is the single crystalline phase of manganese-doped willemite.Fig. 3 curve b is that this product is in wavelength X
ExcFluorescence spectrum figure under the ultraviolet excitation of=258nm launches very pure green fluorescence, and intensity is very high.
Claims (3)
1, low-temperature solid phase reaction prepares the method for manganese-doped willemite green emitting phosphor, comprises the steps:
(1) under 0-30 ℃ of temperature condition, presses chemical general formula: Zn
2-xMn
xSiO
4In stoichiometric ratio, x=0.01-0.24, accurately take by weighing can be dissolved in alcoholic solvent contain the oxygen zinc salt, in the time of being dissolved in alcoholic solvent and pyrolytic decomposition ionic valence condition constant contain oxygen manganous salt and mesopore silicon oxide, simultaneously be dissolved in the alcoholic solvent fully zinc salt and manganous salt, after adding mesopore silicon oxide, ultrasonic dispersing, continuously stirring becomes suspension again;
(2) under 0-30 ℃ of temperature condition, above-mentioned suspension complete drying is become mixed powder;
(3) under the neutral gas protection, solid state reaction under the 750-950 ℃ of temperature condition, soaking time 1-6 hour.
2, the method for preparing the manganese-doped willemite green emitting phosphor by the described low-temperature solid phase reaction of claim 1 is characterized in that described zinc salt is the alkoxide of zinc nitrate or zinc nitrite or zinc acetate or zinc.
3, the method for preparing the manganese-doped willemite green emitting phosphor by the described low-temperature solid phase reaction of claim 1 is characterized in that described manganous salt is the alkoxide that manganous acetate or formic acid manganese or manganese naphthenate or six ethanol close Manganous chloride tetrahydrate or manganese.
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| CN101402459B (en) * | 2007-10-01 | 2010-12-15 | 中国科学院合肥物质科学研究院 | Stephanoporate zinc silicate and method of producing the same |
| CN101671559B (en) * | 2009-09-19 | 2013-04-03 | 桂林理工大学 | Method for preparing M2SiO4-based fluorescent powders at lower temperature |
| JP5636099B2 (en) * | 2010-06-30 | 2014-12-03 | オーシャンズ キング ライティング サイエンスアンドテクノロジー カンパニー リミテッド | Zinc-manganese silicate light-emitting material containing metal particles and preparation method thereof |
| CN103773363A (en) * | 2013-12-17 | 2014-05-07 | 中国计量学院 | Green manganese-activated zinc silicate fluorescent powder and preparation method thereof |
| CN104774608B (en) * | 2015-03-02 | 2019-03-22 | 徐州盛唐光电科技有限公司 | A kind of rear-earth-doped α ' phase Sr2SiO4Nano-powder and preparation method thereof |
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