A long-lasting luminescent material capable of emitting ultraviolet light and a preparation method thereof

Abstract

The present invention discloses a long-lasting luminescent material capable of emitting ultraviolet light and a preparation method thereof, belonging to the technical field of long-lasting luminescent materials. The long-lasting luminescent material capable of emitting ultraviolet light has the general formula shown in formula (I): Na2M 1‑x Ge2O6:xBi 3+ Formula (I); wherein M is selected from one or more of Ca, Sr, and Ba, and 0.0001≤x≤0.1. The long-afterglow luminescent material capable of emitting ultraviolet light uses Na2MGe2O6 as a matrix and trivalent Bi ions as luminescent centers, enabling the material to be effectively excited by ultraviolet light, particularly 254nm ultraviolet light, and exhibiting a bright afterglow with a long afterglow duration, which can last up to 24 hours. Furthermore, the preparation process of the long-afterglow material is simple, the raw material cost is low, and the product has stable chemical properties, is fluffy, easy to grind, non-radioactive, and has minimal environmental pollution.

Description

Technical Field

[0001] The present invention relates to the technical field of long-afterglow luminescent materials, and in particular to a long-afterglow luminescent material capable of emitting ultraviolet light and a preparation method thereof. Background Art

[0002] Long afterglow luminescence is an interesting optical phenomenon, that is, the luminescence can still be maintained for a considerable period of time after the excitation light source is removed. Due to its unique properties, long afterglow materials are widely used in many fields such as AC-LED, biological imaging, emergency lighting and information storage. In recent years, visible and near-infrared long afterglow materials have been rapidly developed and even commercialized in some application fields. The best of these phosphors is CaAl2O4:Eu 2+ 、Nd 3+ (blue), SrAl2O4:Eu 2+ 、Dy 3 + (green), Y2O2S:Eu 3+ Mg 2+ 、Ti 4+ (red), Zn3Ga2Ge2O 10 :Cr 3+ (Near infrared). In particular, near-infrared long afterglow materials have attracted great attention in recent years due to their outstanding tissue penetration ability, and have promoted the development of bioimaging or biomedicine in some aspects. Although these visible light and near-infrared long afterglow materials have made some breakthroughs, people have not paid enough attention to ultraviolet long afterglow materials. It is known that ultraviolet long afterglow materials have potential application prospects in photodynamic therapy, 3D printing and photocatalysis. However, due to the lack of suitable luminescent centers and matrices, the development of ultraviolet long afterglow materials has encountered various obstacles and limitations. At present, only a few ultraviolet long afterglow phosphors have been reported, which cannot meet current needs. Therefore, it is urgent to design and explore excellent ultraviolet long afterglow materials with suitable emission wavelength, luminous intensity and duration. Summary of the Invention

[0003] In view of this, the technical problem to be solved by the present invention is to provide a long-lasting luminescent material capable of emitting ultraviolet light and a preparation method thereof. The long-lasting luminescent material capable of emitting ultraviolet light has a bright afterglow under the excitation of 254nm ultraviolet light and a long afterglow time, which can last up to 24 hours.

[0004] In order to achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0005] The present invention provides a long-lasting luminescent material capable of emitting ultraviolet light, having the general formula (I):

[0006] Na2M 1-xGe2O6:xBi 3+ Formula (I)

[0007] The long afterglow luminescent material uses Na2MGe2O6 as a matrix and trivalent Bi ions as luminescent centers.

[0008] Among them, preferably, M is selected from one or more of Ca, Sr, and Ba.

[0009] X represents the molar ratio of dopant ions (trivalent Bi ions) to M atoms.

[0010] Preferably, 0.0001≤x≤0.1.

[0011] More preferably, in the present invention, the M is selected from Ca, Sr or Ba.

[0012] The above-mentioned long afterglow luminescent material is preferably Na2Ca 1-x Ge2O6:xBi 3+ or Na2Sr 1-x Ge2O6:xBi 3+ or Na2Ba 1- x Ge2O6:xBi 3+ More preferably, the M is selected from Ca or Sr; more preferably, the M is selected from Ca. 1-x Ge2O6:xBi 3+ With a better afterglow duration, in some specific embodiments of the present invention, the long afterglow luminescent material Na2Ca 0.999 Ge2O6:0.001Bi 3+ The afterglow can last for more than 24 hours.

[0013] More preferably, the 0.0005≤x≤0.01; further preferably, the 0.0007≤x≤0.005. In some specific embodiments of the present invention, the x is preferably 0.001 or 0.0005 or 0.01.

[0014] Preferably, the molecular formula of the long-lasting luminescent material capable of emitting ultraviolet light is as shown in any one of Formulas (I-1) to (I-5):

[0015] Na2Ca 0.999 Ge2O6:0.001Bi 3+ Formula (I-1);

[0016] Na2Ca 0.9995 Ge2O6:0.0005Bi 3+ Formula (I-2);

[0017] Na2Ca 0.99 Ge2O6:0.01Bi 3+ Formula (I-3);

[0018] Na2Sr 0.999 Ge2O6:0.001Bi 3+ Formula (I-4);

[0019] Na2Ba 0.999 Ge2O6:0.001Bi 3+ Formula (I-5).

[0020] The present invention also provides a method for preparing a long-lasting luminescent material capable of emitting ultraviolet light, comprising the following steps:

[0021] Mixing a sodium source, an M source, a germanium source and a bismuth source, and calcining the mixture to obtain a long-lasting luminescent material capable of emitting ultraviolet light;

[0022] The M source is selected from one or more of a calcium source, a strontium source, and a barium source.

[0023] The present invention has no particular limitation on the mixing process. The sodium source, M source, germanium source and bismuth source are mixed using a mixing method well known to those skilled in the art.

[0024] Preferably, the molar ratio of the sodium element in the sodium source, the M element in the M source, the germanium element in the germanium source, and the bismuth element in the bismuth source is 2:(0.9-0.9999):2:(0.0001-0.01); more preferably, it is 2:(0.99-0.9995):2:(0.0005-0.01).

[0025] In some specific embodiments of the present invention, the molar ratio of the sodium element in the sodium source, the M element in the M source, the germanium element in the germanium source, and the bismuth element in the bismuth source is 2:0.999:2:0.001 or 2:0.9995:2:0.0005 or 2:0.99:2:0.01.

[0026] Preferably, the sodium source is selected from sodium carbonate and / or nitrate; more preferably, Na2CO3 or NaNO3.

[0027] Preferably, the M source is selected from one or more of M oxides, carbonates, hydroxides, and nitrates; more preferably, the M source is selected from CaCO3, SrCO3, BaCO3, or CaO.

[0028] Preferably, the germanium source is selected from germanium oxides and / or nitrates; more preferably, the germanium source is selected from GeO2 or Ge(NO3)4.

[0029] Preferably, the bismuth source is selected from bismuth oxides and / or nitrates; more preferably, the bismuth source is selected from Bi2O 3。

[0030] The Na2CO3, NaNO3, CaCO3, SrCO3, BaCO3, CaO, GeO2 or Ge(NO3)4 are all analytically pure, and Bi2O3 is spectrally pure.

[0031] The calcination in the above preparation method is carried out under a certain atmosphere.

[0032] Preferably, the calcination is carried out in an atmosphere of air, hydrogen, carbon monoxide, nitrogen or a nitrogen-hydrogen mixture; more preferably, the calcination is carried out in an atmosphere of air.

[0033] The present invention has no special limitation on the above-mentioned roasting device, and any roasting device well known to those skilled in the art can be used.

[0034] In the present invention, a high temperature furnace is preferably used for calcination.

[0035] Preferably, the calcination temperature is 800°C to 1100°C, more preferably 900°C to 1050°C, and even more preferably 1000°C. In some specific embodiments of the present invention, the calcination temperature is preferably 900°C, 1000°C, or 1100°C.

[0036] Preferably, the calcination time is 1 to 24 hours; more preferably 3 to 8 hours; further preferably 6 hours.

[0037] After the calcination is completed, the calcined product is naturally cooled to room temperature.

[0038] The room temperature is preferably 20°C to 30°C.

[0039] Then, the product obtained by calcination is ground to obtain ultraviolet long afterglow phosphor.

[0040] Compared with the prior art, the long afterglow luminescent material capable of emitting ultraviolet light provided by the present invention has the general formula shown in formula (I): Na2M 1-x Ge2O6:xBi 3+ Formula (I); wherein M is selected from one or more of Ca, Sr, and Ba, and 0.0001≤x≤0.1. The long-afterglow luminescent material capable of emitting ultraviolet light uses Na2MGe2O6 as a matrix and trivalent Bi ions as luminescent centers, enabling the material to be effectively excited by ultraviolet light, particularly 254nm ultraviolet light, and exhibiting a bright afterglow with a long afterglow duration, which can last up to 24 hours. Furthermore, the preparation process of the long-afterglow material is simple, the raw material cost is low, and the product has stable chemical properties, is fluffy, easy to grind, non-radioactive, and has minimal environmental pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 The XRD powder diffraction pattern of the ultraviolet long afterglow phosphor prepared in Example 1;

[0042] Figure 2 is the excitation-emission spectrum of the ultraviolet long afterglow phosphor prepared in Example 1;

[0043] Figure 3 is the afterglow luminescence spectrum of the ultraviolet long afterglow phosphor prepared in Example 1;

[0044] Figure 4 This is the afterglow decay curve of the ultraviolet long afterglow phosphor prepared in Example 1. DETAILED DESCRIPTION

[0045] To further illustrate the present invention, the long afterglow luminescent material capable of emitting ultraviolet light and the preparation method thereof provided by the present invention are described in detail below with reference to the embodiments.

[0046] Example 1

[0047] The raw materials are Na2CO3 (analytical grade), CaCO3 (analytical grade), GeO2 (analytical grade), and Bi2O3 (spectrally pure). The molar ratio between them is 1:0.999:2:0.0005. The raw materials are weighed according to the above ratio, mixed and placed in a corundum crucible. Then, the crucible is placed in a high-temperature furnace and calcined at 1000℃ in an air atmosphere for 6 hours. After cooling naturally to room temperature, a long-lasting ultraviolet phosphor is obtained. The obtained phosphor is a white powder with the molecular formula of Na2Ca 0.999 Ge2O6:0.001Bi 3+ , Figure 1 The maximum excitation peak of the prepared ultraviolet long afterglow phosphor is located at about 315nm. Figure 2 As shown in the figure, under 315nm excitation, the emission wavelength peak of the phosphor is located near 375nm; the afterglow luminescence spectrum and afterglow decay curve of the material are shown in the figure. Figure 3 、 4 As shown in FIG, under the excitation of 254nm ultraviolet light, the afterglow of the ultraviolet long afterglow phosphor can last for more than 24 hours.

[0048] Example 2

[0049] The raw materials are Na2CO3 (analytical grade), CaCO3 (analytical grade), GeO2 (analytical grade), and Bi2O3 (spectrally pure). The molar ratio between them is 1:0.999:2:0.0005. The raw materials are weighed according to the above ratio, mixed and placed in a corundum crucible. Then, the crucible is placed in a high-temperature furnace and calcined at 1000℃ in a nitrogen atmosphere for 6 hours. After cooling naturally to room temperature, a long-lasting ultraviolet phosphor is obtained. The obtained phosphor is a white powder with the molecular formula of Na2Ca 0.999 Ge2O6:0.001Bi 3+ The maximum excitation peak of its excitation spectrum is located at around 315nm. Under 315nm excitation, the emission wavelength peak of the phosphor is located near 375nm. Under 254nm ultraviolet light excitation, the afterglow of the ultraviolet long afterglow phosphor can last for more than 20 hours.

[0050] Example 3

[0051] The raw materials are Na2CO3 (analytical grade), CaCO3 (analytical grade), GeO2 (analytical grade), and Bi2O3 (spectrally pure). The molar ratio between them is 1:0.999:2:0.0005. The raw materials are weighed according to the above ratio, mixed and placed in a corundum crucible. Then, the crucible is placed in a high-temperature furnace and calcined at 1000℃ in a nitrogen-hydrogen mixed gas atmosphere for 6 hours. After cooling naturally to room temperature, a UV long afterglow phosphor is obtained. The obtained phosphor is a white powder with the molecular formula of Na2Ca 0.999 Ge2O6:0.001Bi 3+ The maximum excitation peak of its excitation spectrum is located at around 315nm. Under 315nm excitation, the emission wavelength peak of the phosphor is located near 375nm; under 254nm ultraviolet light excitation, the afterglow of the ultraviolet long afterglow phosphor can last for more than 18 hours.

[0052] Example 4

[0053] The raw materials are Na2CO3 (analytical grade), CaCO3 (analytical grade), GeO2 (analytical grade), and Bi2O3 (spectrally pure). The molar ratio between them is 1:0.999:2:0.0005. The raw materials are weighed according to the above ratio, mixed and placed in a corundum crucible. Then, the crucible is placed in a high-temperature furnace and calcined at 900℃ in air atmosphere for 6 hours. After cooling naturally to room temperature, a long-lasting ultraviolet phosphor is obtained. The obtained phosphor is a white powder with the molecular formula of Na2Ca 0.999 Ge2O6:0.001Bi 3+ The maximum excitation peak of its excitation spectrum is located at around 315nm. Under 315nm excitation, the emission wavelength peak of the phosphor is located near 375nm; under 254nm ultraviolet light excitation, the afterglow of the ultraviolet long afterglow phosphor can last for more than 18 hours.

[0054] Example 5

[0055] The raw materials are Na2CO3 (analytical grade), CaCO3 (analytical grade), GeO2 (analytical grade), and Bi2O3 (spectrally pure). The molar ratio between them is 1:0.999:2:0.0005. The raw materials are weighed according to the above ratio, mixed and placed in a corundum crucible. Then, the crucible is placed in a high-temperature furnace and calcined at 1100℃ in air atmosphere for 6 hours. After cooling naturally to room temperature, a long-lasting ultraviolet phosphor is obtained. The obtained phosphor is a white powder with the molecular formula of Na2Ca 0.999 Ge2O6:0.001Bi 3+ The maximum excitation peak of its excitation spectrum is located at around 315nm. Under 315nm excitation, the emission wavelength peak of the phosphor is located near 375nm; under 254nm ultraviolet light excitation, the afterglow of the ultraviolet long afterglow phosphor can last for more than 18 hours.

[0056] Example 6

[0057] The raw materials are Na2CO3 (analytical grade), SrCO3 (analytical grade), GeO2 (analytical grade), and Bi2O3 (spectrally pure). The molar ratio between them is 1:0.999:2:0.0005. The raw materials are weighed according to the above ratio, mixed and placed in a corundum crucible. Then, the crucible is placed in a high-temperature furnace and calcined at 1000℃ in air atmosphere for 6 hours. After cooling naturally to room temperature, a long-lasting ultraviolet phosphor is obtained. The obtained phosphor is a white powder with the molecular formula of Na2Sr 0.999 Ge2O6:0.001Bi 3+ The maximum excitation peak of its excitation spectrum is located at around 315nm. Under 315nm excitation, the emission wavelength peak of the phosphor is located near 375nm; under 254nm ultraviolet light excitation, the afterglow of the ultraviolet long afterglow phosphor can last for more than 15 hours.

[0058] Example 7

[0059] The raw materials are Na2CO3 (analytical grade), BaCO3 (analytical grade), GeO2 (analytical grade), and Bi2O3 (spectrally pure). The molar ratio between them is 1:0.999:2:0.0005. The raw materials are weighed according to the above ratio, mixed and placed in a corundum crucible. Then, the crucible is placed in a high-temperature furnace and calcined at 1000℃ in air atmosphere for 6 hours. After cooling naturally to room temperature, a long-lasting ultraviolet phosphor is obtained. The obtained phosphor is a white powder with the molecular formula of Na2Sr 0.999 Ge2O6:0.001Bi 3+The maximum excitation peak of its excitation spectrum is located at around 315nm. Under 315nm excitation, the emission wavelength peak of the phosphor is located near 375nm; under 254nm ultraviolet light excitation, the afterglow of the ultraviolet long afterglow phosphor can last for more than 12 hours.

[0060] Example 8

[0061] The raw materials are NaNO3 (analytical grade), CaCO3 (analytical grade), GeO2 (analytical grade), and Bi2O3 (spectrally pure). The molar ratio between them is 2:0.999:2:0.0005. The raw materials are weighed according to the above ratio, mixed and placed in a corundum crucible. Then, the crucible is placed in a high-temperature furnace and calcined at 1000℃ in air atmosphere for 6 hours. After cooling naturally to room temperature, a long-lasting ultraviolet phosphor is obtained. The obtained phosphor is a white powder with the molecular formula of Na2Ca 0.999 Ge2O6:0.001Bi 3+ The maximum excitation peak of its excitation spectrum is located at around 315nm. Under 315nm excitation, the emission wavelength peak of the phosphor is located near 375nm; under 254nm ultraviolet light excitation, the afterglow of the ultraviolet long afterglow phosphor can last for more than 18 hours.

[0062] Example 9

[0063] The raw materials are Na2CO3 (analytical grade), CaO (analytical grade), GeO2 (analytical grade), and Bi2O3 (spectrally pure). The molar ratio between them is 1:0.999:2:0.0005. The raw materials are weighed according to the above ratio, mixed and placed in a corundum crucible. Then, the crucible is placed in a high-temperature furnace and calcined at 1000℃ in air atmosphere for 6 hours. After cooling naturally to room temperature, a long-lasting ultraviolet phosphor is obtained. The obtained phosphor is a white powder with the molecular formula of Na2Ca 0.999 Ge2O6:0.001Bi 3+ The maximum excitation peak of its excitation spectrum is located at around 315nm. Under 315nm excitation, the emission wavelength peak of the phosphor is located near 375nm; under 254nm ultraviolet light excitation, the afterglow of the ultraviolet long afterglow phosphor can last for more than 18 hours.

[0064] Example 10

[0065] The raw materials are Na2CO3 (analytical grade), CaCO3 (analytical grade), Ge(NO3)4 (analytical grade), and Bi2O3 (spectrally pure). The molar ratio between them is 1:0.999:2:0.0005. The raw materials are weighed according to the above ratio, mixed and placed in a corundum crucible. Then, the crucible is placed in a high-temperature furnace and calcined at 1000℃ in air atmosphere for 6 hours. After cooling naturally to room temperature, a long-lasting ultraviolet phosphor is obtained. The obtained phosphor is a white powder with the molecular formula of Na2Ca 0.999 Ge2O6:0.001Bi 3+ The maximum excitation peak of its excitation spectrum is located at around 315nm. Under 315nm excitation, the emission wavelength peak of the phosphor is located near 375nm; under 254nm ultraviolet light excitation, the afterglow of the ultraviolet long afterglow phosphor can last for more than 18 hours.

[0066] Example 11

[0067] The raw materials are Na2CO3 (analytical grade), CaCO3 (analytical grade), GeO2 (analytical grade), and Bi2O3 (spectrally pure). The molar ratio between them is 1:0.9995:2:0.00025. The raw materials are weighed according to the above ratio, mixed and placed in a corundum crucible. Then, the crucible is placed in a high-temperature furnace and calcined at 1000℃ in air atmosphere for 6 hours. After cooling naturally to room temperature, a long-lasting ultraviolet phosphor is obtained. The obtained phosphor is a white powder with the molecular formula of Na2Ca 0.9995 Ge2O6:0.0005Bi 3+ The maximum excitation peak of its excitation spectrum is located at around 315nm. Under 315nm excitation, the emission wavelength peak of the phosphor is located near 375nm; under 254nm ultraviolet light excitation, the afterglow of the ultraviolet long afterglow phosphor can last for more than 12 hours.

[0068] Example 12

[0069] The raw materials are Na2CO3 (analytical grade), CaCO3 (analytical grade), GeO2 (analytical grade), and Bi2O3 (spectrally pure). The molar ratio between them is 1:0.99:2:0.005. The raw materials are weighed according to the above ratio, mixed and placed in a corundum crucible. Then, the crucible is placed in a high-temperature furnace and calcined at 1100℃ in air atmosphere for 6 hours. After cooling naturally to room temperature, a long-lasting ultraviolet phosphor is obtained. The obtained phosphor is a white powder with the molecular formula of Na2Ca 0.99 Ge2O6:0.01Bi 3+ The maximum excitation peak of its excitation spectrum is located at around 315nm. Under 315nm excitation, the emission wavelength peak of the phosphor is located near 375nm; under 254nm ultraviolet light excitation, the afterglow of the ultraviolet long afterglow phosphor can last for more than 10 hours.

[0070] The above embodiments are only intended to help understand the method and core concept of the present invention. It should be noted that, without departing from the principles of the present invention, a number of improvements and modifications may be made to the present invention by those skilled in the art, and such improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A long afterglow luminescent material capable of emitting ultraviolet light, characterized in that: It has the general formula shown in formula (I): Na2M 1-x Ge2O6:xBi 3+ Formula (I) Wherein, M is selected from one or more of Ca, Sr, and Ba; 0.0001≤x≤0.1。 2. The long afterglow luminescent material capable of emitting ultraviolet light according to claim 1, characterized in that: The M is selected from Ca or Sr.

3. The long-lasting luminescent material capable of emitting ultraviolet light according to claim 1, characterized in that: The range of x is 0.0005≤x≤0.

01.

4. The long-lasting luminescent material capable of emitting ultraviolet light according to claim 1, characterized in that: The molecular formula of the long afterglow luminescent material capable of emitting ultraviolet light is shown in any one of Formulas (I-1) to (I-5): Na2Ca 0.999 Ge2O6:0.001Bi 3+ Formula (I-1); Na2Ca 0.9995 Ge2O6:0.0005Bi 3+ Formula (I-2); Na2Ca 0.99 Ge2O6:0.01Bi 3+ Formula (I-3); Na2Sr 0.999 Ge2O6:0.001Bi 3+ Formula (I-4); Na2Ba 0.999 Ge2O6:0.001Bi 3+ Formula (I-5).

5. The method for preparing the long-lasting luminescent material capable of emitting ultraviolet light according to any one of claims 1 to 4, characterized in that: The following steps are involved: Mixing a sodium source, an M source, a germanium source and a bismuth source, and calcining the mixture to obtain a long-lasting luminescent material capable of emitting ultraviolet light; The M source is selected from one or more of a calcium source, a strontium source, and a barium source.

6. The preparation method according to claim 5, characterized in that The molar ratio of the sodium element in the sodium source, the M element in the M source, the germanium element in the germanium source, and the bismuth element in the bismuth source is 2: (0.9-0.9999): 2: (0.0001-0.01).

7. The preparation method according to claim 5, characterized in that The sodium source is selected from sodium carbonate and / or nitrate; The M source is selected from one or more of oxides, carbonates, hydroxides, and nitrates of M; The germanium source is selected from germanium oxides and / or nitrates; The bismuth source is selected from bismuth oxides and / or nitrates.

8. The preparation method according to claim 5, characterized in that The calcination is carried out in an atmosphere of air, hydrogen, carbon monoxide, nitrogen or a nitrogen-hydrogen mixed gas.

9. The preparation method according to claim 5, characterized in that The calcination temperature is 800°C to 1100°C; The calcination time is 1 to 24 hours.

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