Green gallate fluorescent powder and preparation and application thereof

Abstract

The application discloses a kind of green gallate fluorescent powder and preparation and application thereof, the chemical formula of this fluorescent powder is Y 3‑x GaO6:xTb 3+ Wherein x is 0-0.09, and not equal to 0.The preparation method comprises: Y2O3, Ga2O3 and Tb4O7 are mixed, anhydrous ethanol is added and grinded;in air atmosphere, the grinded powder is sintered and kept warm at a rate of 5 ℃ / min to 1300-1500 ℃, and then cooled to 800 ℃ at a rate of 5 ℃ / min, and then naturally cooled, grinded into powder, to obtain fluorescent powder.The application solves the problem that the preparation process of prior art is complex and needs non-air atmosphere sintering.The application uses high-temperature solid-phase synthesis method, material preparation is simple, period is short, cost is low, does not need inert atmosphere or reducing atmosphere treatment, the stress luminescence fluorescent powder prepared has good chemical stability, and is not easy to deliquesce, and green stress luminescence phenomenon can be generated under mechanical stimulation.

Description

TECHNICAL FIELD

[0001] The present application relates to a stress luminescent material, in particular to a green gallate fluorescent powder and its preparation and application. BACKGROUND

[0002] Stress luminescence, also known as mechanical luminescence, refers to the luminescence phenomenon generated by a material when it is stimulated by external mechanical force. The so-called mechanical stimulation includes many forms, such as stretching, rubbing, extrusion, impact, and even wind and raindrops. According to the different types of applied mechanical stimulation, it can be divided into deformation stress luminescence and friction stress luminescence. Stress luminescent material is an energy conversion material that converts force into light. Generally, the emission intensity of stress luminescence of the material has a precise linear relationship with the applied mechanical force within the elastic deformation range, and reliable stress distribution can be directly obtained by real-time monitoring of the luminescence intensity, which has great advantages in energy saving and environmental protection, and therefore has broad development prospects in the fields of stress sensors, crack monitoring, anti-counterfeiting encryption, etc.

[0003] Most stress luminescent materials are produced by doping rare earth ions (such as Eu 2+ , Tb 3+ , Nd 3+ ) or transition metal ions (such as Mn 2+ , Cu + ). 2+ , SrAl2O4:Eu 2+ , Sr3Al2O6:Eu 2+ and LiNbO3:Pr 3+ , can adjust the intensity and color of stress luminescence by doping different ions and different concentrations, and have no effect on the integrity of the host crystal.

[0004] The color of the stress luminescent material at the present stage has covered the entire visible light spectrum, and green light is the color that the human eye is most likely to capture, but the research on green stress luminescent material is still in the early stage. The existing document 1 (Qin S, Bian J, Han Y, et al. Intense and efficient green mechanoluminescence in CaLaAl3O7 through Tb 3+ doping [J]. Materials Research Bulletin, 2021, 145: 111535) discloses GaLaAl3O:Tb 3+SrAl2O4:Eu 2+ ,Dy 3+ has strong stress luminescence intensity, and is a stress luminescence material with good performance, but the material preparation condition is complex, nitrogen atmosphere sintering needs to be used, the preparation cost is high, and toxic substances are generated in the preparation process, which is harmful to human body and is not conducive to environmental protection. The SrAl2O4:Eu 2+ ,Dy 3+ fluorescent flexible film, but the preparation process is complex, the preparation period is long, reduction carbon atmosphere sintering is needed, the preparation cost is high, and the prepared fluorescent powder is easy to deliquesce and is not easy to store. Therefore, the preparation process of the prior art is complex and needs non-air atmosphere sintering. SUMMARY

[0005] The purpose of the present application is to provide a green gallate fluorescent powder and its preparation and application. The problem of complex preparation process and the need for non-air atmosphere sintering in the prior art is solved.

[0006] In order to achieve the above purpose, the present application provides a green gallate fluorescent powder, the chemical formula of which is Y 3-x GaO6:xTb 3+ , wherein x is 0-0.09 and not equal to 0.

[0007] Preferably, the x is 0.01, 0.03, 0.05, 0.07 or 0.09.

[0008] More preferably, the x is 0.07. The brightness of the fluorescent powder increases first and then decreases with the increase of the doping amount of Tb 3+ , and the brightness is the largest when x is 0.07; when x is 0.06 or 0.08, the brightness of the fluorescent powder is slightly lower than that when x is 0.07.

[0009] The present application provides a preparation method of the green gallate fluorescent powder as described, which comprises:

[0010] (1) mixing Y2O3, Ga2O3 and Tb4O7, adding anhydrous ethanol to grind, to obtain uniformly ground powder;

[0011] (2) under air atmosphere, sintering the uniformly ground powder at a rate of 5℃ / min to 1300-1500℃ (sintering temperature below 1300℃, a small amount of raw material components will exist in the obtained product) and holding, then reducing to 800℃ at a rate of 5℃ / min, and then naturally cooling, to obtain a sintered product;

[0012] (3) grinding the sintered product into powder, to obtain a fluorescent powder.

[0013] Preferably, in step (1), the substance amount ratio of Y2O3, Ga2O3 and Tb4O7 is (6-2x) : 2 : x, wherein x is 0-0.09, and not equal to 0. The substance amount ratio is the most important influencing factor, if the substance amount ratio is other values, the fluorescent powder material cannot be obtained.

[0014] Preferably, in step (1), the purity of Y2O3, Ga2O3 and Tb4O7 is all 99.99%; the purity of anhydrous ethanol is 99.5%; and the grinding time is 30min-60min. Too low reactant purity will make the product impure, too short grinding time will cause the raw materials to be mixed unevenly, and also can cause the production of impure product. Too short or too long holding time will cause incomplete or excessive crystallization, and the stress luminescence brightness of the obtained material is not ideal.

[0015] Reactant purity, grinding time, sintering temperature, holding time are important influencing factors,

[0016] Preferably, in step (2), the holding time is 5-7h. Too short or too long holding time will cause incomplete or excessive crystallization, and the stress luminescence brightness of the obtained material is not ideal.

[0017] Preferably, in step (2), the sintering temperature is 1450℃.

[0018] The application provides an application of the green gallate fluorescent powder as described in preparing a stress luminescence material.

[0019] Preferably, the prepared stress luminescence material will produce green stress luminescence phenomenon under mechanical stimulation.

[0020] The application discloses a green gallate fluorescent powder, and a preparation and application thereof.

[0021] 1. The application can produce green stress luminescence phenomenon under mechanical stimulation. 3+Tb 3+ substitutes Y 3+ , when Tb 3 + enters the lattice, a local energy level, i.e. a trap, is generated in the forbidden band region; the light emitting mechanism is that the electrons at the top of the valence band jump to the bottom of the conduction band, part of the carriers are captured and stored by the trap energy level, when a mechanical stimulus is applied, a piezoelectric field is generated, the carriers in the trap are released, the light emitting center obtains the energy of the electron and hole recombination, thereby stress luminescence is generated.

[0022] 2、The high-temperature solid-phase synthesis method is adopted in the application, material preparation is simple, the period is short, the cost is low, and the prepared stress luminescence fluorescent powder is good in chemical stability and not easy to deliquesce, and green stress luminescence phenomenon is generated under mechanical stimulation, and green is the color most easily captured by the human eye. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The XRD pattern of Y 3-x GaO6:xTb 3+ fluorescent powder prepared in the application examples 1-5.

[0024] Figure 2 The excitation spectrum diagram of Y 3-x GaO6:xTb 3+ fluorescent powder prepared in the application examples 1-5.

[0025] Figure 3 The emission spectrum diagram of Y 3-x GaO6:xTb 3+ fluorescent powder prepared in the application examples 1-5 under 542nm excitation.

[0026] Figure 4 The stress luminescence spectrum diagram of Y 2.93 GaO6:0.07Tb 3+ fluorescent powder prepared in the application example 4.

[0027] Figure 5 The XRD pattern of Y 2.93 GaO6:0.07Tb 3+ fluorescent powder prepared in the application examples 6 and 7.

[0028] Figure 6 The ML spectrum of Y 2.93 GaO6:0.07Tb 3+ fluorescent powder prepared in the application examples 6 and 7.

[0029] Figure 7The light emission diagram of the material prepared in Example 4 and Comparative Examples 1-2 under a pulling force of 5N is shown in the following figure. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0031] Example 1

[0032] A green gallate fluorescent powder Y 2.99 GaO6:0.01Tb 3+ (Y 3-x GaO6, x=0.01) is prepared by the following method, which comprises:

[0033] (1) 0.7795 g of Y2O3 (purity 99.99%), 0.2164 g of Ga2O3 (purity 99.99%) and 0.0043 g of Tb4O7 (purity 99.99%) weighed according to the stoichiometric ratio are put into an agate mortar, 10 mL of anhydrous ethanol (purity 99.95%) is added (the amount of anhydrous ethanol added is just enough to cover the raw materials to ensure that the raw materials are fully mixed), and grinding is performed for 30-60 min to obtain uniformly ground powder.

[0034] (2) The uniformly ground powder is loaded into a corundum crucible, dried in an oven at 50°C for 30 min, loaded into a muffle furnace, heated to 1450°C at a rate of 5°C / min and kept for 5 h, then cooled to 800°C at a rate of 5°C / min, and then naturally cooled.

[0035] (3) The sintered product after cooling is ground (for 10 min) into powder in an agate mortar to obtain the fluorescent powder.

[0036] Example 2

[0037] A green gallate fluorescent powder Y 2.97 GaO6:0.03Tb 3+ (Y 3-x GaO6, x=0.03) is prepared by the method basically same as that in Example 1, with the difference being that:

[0038] In step (1), the mass of Y2O3 is adjusted from 0.7795 g to 0.7718 g, the mass of Ga2O3 is adjusted from 0.2164 g to 0.2157 g, and the mass of Tb4O7 is adjusted from 0.0043 g to 0.0129 g.

[0039] Example 3

[0040] A green gallate fluorescent powder Y 2.95 GaO6:0.05Tb 3+ (Y 3-x GaO6, x=0.05) is basically the same as that of Example 1, except that:

[0041] In step (1), the mass of Y2O3 is adjusted from 0.7795 g to 0.7641 g, the mass of Ga2O3 is adjusted from 0.2164 g to 0.2150 g, and the mass of Tb4O7 is adjusted from 0.0043 g to 0.0214 g.

[0042] Example 4

[0043] A green gallate fluorescent powder Y 2.93 GaO6:0.07Tb 3+ (Y 3-x GaO6, x=0.07) is basically the same as that of Example 1, except that:

[0044] In step (1), the mass of Y2O3 is adjusted from 0.7795 g to 0.7565 g, the mass of Ga2O3 is adjusted from 0.2164 g to 0.2143 g, and the mass of Tb4O7 is adjusted from 0.0043 g to 0.0299 g.

[0045] Example 5

[0046] A green gallate fluorescent powder Y 2.91 GaO6:0.09Tb 3+ (Y 3-x GaO6, x=0.09) is basically the same as that of Example 1, except that:

[0047] In step (1), the mass of Y2O3 is adjusted from 0.7795 g to 0.7489 g, the mass of Ga2O3 is adjusted from 0.2164 g to 0.2136 g, and the mass of Tb4O7 is adjusted from 0.0043 g to 0.0383 g.

[0048] Example 6

[0049] A green gallate fluorescent powder Y 2.93 GaO6:0.07Tb 3+ (Y 3-x GaO6, x=0.07) is basically the same as that of Example 1, except that:

[0050] In step (2), the holding temperature is adjusted from 1450°C to 1300°C.

[0051] Example 7

[0052] A green gallate fluorescent powder Y 2.93 GaO6:0.07Tb 3+ (Y 3-x GaO6, x = 0.07) is basically the same as that of Example 1, except that:

[0053] In step (3), the holding temperature is adjusted from 1450°C to 1500°C.

[0054] Comparative Example 1

[0055] Reference 1 (Understanding the mechanoluminescent mechanisms of manganese-doped zinc sulfide based on load effects [J]. Journal of Luminescence, 2018, 203: 683-688) prepared ZnS:Mn 2+ fluorescent powder, the method comprises:

[0056] (1) 0.9518 g of ZnS (≥99.99%), 2.0719 g of MnCl2·4H2O (≥99.0%), 0.18 g of MgCl2·6H2O (≥98.0%) and 0.27 g of NaCl (≥99.5%) were weighed according to the stoichiometric ratio, and 0.18 g of MgCl2·6H2O (≥98.0%) and 0.27 g of NaCl (≥99.5%) were used as fluxing agent, accounting for 15wt% of the raw materials, the molar ratio of MgCl2·6H2O to NaCl was 2:3; the weighed raw materials were placed in an agate mortar and ground with anhydrous ethanol until fully mixed;

[0057] (2) The mixture was loaded into a corundum crucible and placed in a muffle furnace, and then the mixture was sintered at 900°C for 1 h under a nitrogen atmosphere, and cooled to room temperature.

[0058] (3) The material was taken out and washed with deionized water three times to remove chlorides, and then placed in an oven to dry, to obtain ZnS:Mn 2+ fluorescent powder.

[0059] Comparative Example 2

[0060] Reference 2 (Qin S, Bian J, Han Y, et al. Intense and efficient green mechanoluminescence in CaLaAl3O7 through Tb 3+doping[J].Materials Research Bulletin,2021,145:111535) to prepare doped GaLaAl3O:Tb 3+ fluorescent powder, the method comprises:

[0061] (1) 0.2691 g of CaCO3 (99.99%), 0.4381 g of La2O3 (99.99%), 0.4113 g of Al2O3 (99.99%), and 0.0050 g of Tb4O7 (99.99%) were weighed according to the stoichiometric ratio, and the weighed raw materials were put into an agate mortar and ground with anhydrous ethanol until they were thoroughly mixed.

[0062] (2) The mixture was transferred to a corundum crucible and placed in a muffle furnace, and the mixture was kept in a reducing atmosphere composed of nitrogen and hydrogen (volume ratio of 90% N2 and 10% H2) for 5 h, and the sample was taken out after cooling to room temperature, and finally GaLaAl3O:Tb 3+ was obtained.

[0063] Experimental Example 1 characterization

[0064] As Figure 1 shown, Y 3-x GaO6:xTb 3+ fluorescent powder prepared by examples 1-5 of the present application has XRD patterns as shown in the figure, wherein the abscissa is 2θ and the ordinate is the relative intensity; x=0.01 is the fluorescent powder Y 2.99 GaO6:0.01Tb 3+ prepared by example 1; x=0.03 is the fluorescent powder Y 2.97 GaO6:0.03Tb 3+ prepared by example 2; x=0.05 is the fluorescent powder Y 2.95 GaO6:0.05Tb 3+ prepared by example 3; x=0.07 is the fluorescent powder Y 2.93 GaO6:0.07Tb 3+ prepared by example 4; x=0.09 is the fluorescent powder Y 2.91 GaO6:0.09Tb 3+ It can be seen from Figure 1 that the diffraction peaks of Y 3-x GaO6:xTb 3+ fluorescent powder prepared by examples 1-5 of the present application correspond well to the standard card, indicating that the Y 3-x GaO6:xTb 3+ fluorescent powder is a pure phase.

[0065] As Figure 2 shown, Y 3-xGaO6:0.01Tb 3+ The excitation spectrum of the fluorescent powder, wherein the abscissa is wavelength and the ordinate is relative intensity; x=0.01 is the fluorescent powder Y prepared in Example 1 2.99 GaO6:0.01Tb 3+ ; x=0.03 is the fluorescent powder Y prepared in Example 2 2.97 GaO6:0.03Tb 3+ ; x=0.05 is the fluorescent powder Y prepared in Example 3 2.95 GaO6:0.05Tb 3+ ; x=0.07 is the fluorescent powder Y prepared in Example 4 2.93 GaO6:0.07Tb 3+ ; x=0.09 is the fluorescent powder Y prepared in Example 5 2.91 GaO6:0.09Tb 3+ It can be seen from Figure 2 that the Y 3-x GaO6:xTb 3+ fluorescent powder prepared in Examples 1-5 has the optimal excitation wavelength of 542 nm.

[0066] As shown in Figure 3 , the Y 3-x GaO6:xTb 3+ fluorescent powder prepared in Examples 1-5 has the emission spectrum under the excitation of 542 nm, wherein the abscissa is wavelength and the ordinate is relative intensity; x=0.01 is the fluorescent powder Y prepared in Example 1 2.99 GaO6:0.01Tb 3+ ; x=0.03 is the fluorescent powder Y prepared in Example 2 2.97 GaO6:0.03Tb 3+ ; x=0.05 is the fluorescent powder Y prepared in Example 3 2.95 GaO6:0.05Tb 3+ ; x=0.07 is the fluorescent powder Y prepared in Example 4 2.93 GaO6:0.07Tb 3+ ; x=0.09 is the fluorescent powder Y prepared in Example 5 2.91 GaO6:0.09Tb 3+ It can be seen from Figure 3 that the Y 3-x GaO6:xTb 3+ fluorescent powder prepared in Examples 1-5 has four emission peaks, and the four emission peaks all correspond to the characteristic emission of Tb 3+ , and the emission intensity first increases and then decreases with the increase of the doping concentration of Tb 3+ . When the doping concentration of Tb 3+ is 0.07, the emission intensity of the material is the strongest.

[0067] As shown in Figure 5 , the Y 2.93 GaO6:0.07Tb 3+ XRD patterns of the phosphor, wherein 130℃ is the sintering temperature of Example 6, and 1500℃ is the sintering temperature of Example 7. It can be seen from Figure 5 that when the sintering temperature is 1300℃, the sample prepared in Example 6 is not a pure phase; and when the sintering temperature is 1500℃, the sample prepared in Example 7 is a pure phase.

[0068] As shown in Figure 6 , the Y 2.93 GaO6:0.07Tb 3+ ML patterns of the phosphor, wherein 130℃ is the sintering temperature of Example 6, 1500℃ is the sintering temperature of Example 7, and 1450℃ is the sintering temperature of Example 1. It can be seen from Figure 6 that the stress luminescence intensity of the materials prepared in Example 6 and Example 7 is far lower than that of the sample prepared in Example 1 (sintering temperature of 1450℃).

[0069] Stress luminescence performance of the phosphor prepared in Example 4 of Experimental Example 2

[0070] Before the stress luminescence performance is characterized, the phosphor (phosphor prepared in Example 4 or material prepared in Comparative Example 1) with a mass ratio of 1.4:1.6:0.16, polydimethylsiloxane A and B (the components of polydimethylsiloxane A and B are both polydimethylsiloxane, and A and B alone cannot form curing, but curing occurs when they are mixed) are poured into a small petri dish, stirred with a glass rod for 30-40 min, mixed uniformly and no bubbles are generated, poured into a dumbbell-shaped polytetrafluoroethylene mold and evenly laid, placed in a 60℃ oven for 2h, and demolded to obtain a stress luminescence material.

[0071] The materials of Comparative Example 1 and Example 4 of the present application do not need to be pre-irradiated, and stress luminescence can be generated directly by applying stress, while Comparative Example 2 needs to be pre-irradiated to generate stress luminescence phenomenon, and if not pre-irradiated, stress will not generate light.

[0072] Test and pre-irradiation steps of Comparative Example 2: SrAl2O4:Eu 2+ ,Dy 3+ phosphor prepared in Comparative Example 2 is mixed with polydimethylsiloxane (PDMS) to prepare SrAl2O4:Eu 2+ ,Dy 3+The flexible film emits fluorescence. Before testing, the material needs to be irradiated by a 385 nm ultraviolet lamp for 5 minutes, then placed for 3 minutes, and then the material is stretched.

[0073] As shown in Figure 4 Fig. 4, the Y 2.93 GaO6:0.07Tb 3+ The stress luminescence spectrum of the fluorescent powder, wherein the abscissa is wavelength and the ordinate is relative intensity. It can be seen from Figure 4 that the Y 2.93 GaO6:0.07Tb 3+ The green gallate stress luminescence material Y 2.99 GaO6:0.01Tb 3+ Without radiation, when stretched (when the elastomer is stretched, a quantitative stretching is adopted, and the deformation amount of the elastomer is 50%, and when the deformation amount exceeds 50%, the elastomer is easy to break), it emits dazzling green light, and the brightness is enough to be captured by the naked eye, and it has self-recovery performance, and the stress luminescence spectrum and the photoluminescence spectrum both have four emission peaks.

[0074] As shown in Figure 7 Fig. 5, the luminescence diagrams of the materials prepared in Example 4 and Comparative Examples 1-2 under a tensile force of 5 N. Wherein a is the luminescence diagram of the material prepared in Example 4 under a tensile force of 5 N; b is the luminescence diagram of the material prepared in Comparative Example 1 under a tensile force of 5 N; and c is the luminescence diagram of the material prepared in Comparative Example 2 under a tensile force of 5 N. It can be seen from Figure 7 that the color of the material prepared in Example 4 is green, the color of Comparative Example 1 is blue-green, and the color of Comparative Example 3 is green. The different colors of the materials prepared in Example 4 and Comparative Examples 1-2 are related to the matrix and the doping elements of the materials, and different matrixes and doping elements will lead to different luminescence centers, thereby emitting light of different wavelengths, thereby leading to different luminescence colors. Compared with Comparative Example 1, the defect of Comparative Example 1 is that it contains a sulfur source, and the material in Example 4 of the present application does not need to be sintered in a non-air atmosphere during preparation, and no toxic substances are released during preparation; compared with Comparative Example 2, the material in Example 4 of the present application does not need to be sintered in a non-air atmosphere during preparation, and the prepared material can realize stress luminescence without ultraviolet irradiation under stress stimulation.

[0075] Under the test conditions of Comparative Example 2, the stress luminescence phenomenon of the material prepared in Example 4 of the present application will not change. Therefore, whether or not pre-irradiation, the material prepared in Example 4 of the present application will not be affected.

[0076] While the application has been described in detail by reference to preferred embodiments thereof, it should be recognized that the description set forth herein is by way of example and that modifications of the procedures described can be employed without departing from the scope of the application. Accordingly, the scope of the application should be determined by the appended claims and equivalents thereof.

Claims

1. Use of a green gallate phosphor in the preparation of a stress luminescence material, characterized in that, The chemical formula of the green gallate fluorescent powder is Y 3-x GaO6:xTb 3+ wherein x is 0-0.09 and not equal to 0.

2. Use according to claim 1, characterized in that, The prepared stress luminescent material can produce green stress luminescence phenomenon under mechanical stimulation.

3. Use according to claim 1, characterized in that, The x is 0.01, 0.03, 0.05, 0.07 or 0.

09.

4. Use according to claim 3, characterized in that, The x is 0.

07.

5. The use according to claim 1, characterized in that, The preparation method of the green gallate fluorescent powder comprises: (1) mixing Y2O3, Ga2O3 and Tb4O7, adding anhydrous ethanol and grinding to obtain uniformly ground powder; (2) sintering the uniformly ground powder under air atmosphere at a rate of 5 ℃ / min to 1300-1500 ℃ and keeping temperature, then cooling at a rate of 5 ℃ / min to 800 ℃, and then naturally cooling to obtain sintered product; (3) grinding the sintered product into powder to obtain fluorescent powder.

6. Use according to claim 5, characterized in that, In step (1), the molar ratio of Y2O3, Ga2O3 and Tb4O7 is (6-2x) : 2 : x, wherein x is 0-0.09 and not equal to 0.

7. Use according to claim 5, characterized in that, In step (1), the purity of Y2O3, Ga2O3 and Tb4O7 is 99.99%; the purity of anhydrous ethanol is 99.5%; and the grinding time is 30-60 min.

8. Use according to claim 5, characterized in that, In step (2), the keeping temperature time is 5-7 h.

9. Use according to claim 5, characterized in that, In step (2), the sintering temperature is 1450 ℃.

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