Photochromic phosphor and preparation method thereof
By doping Bi in BaySrGd4O8, a photochromic phosphor was prepared, which solved the problem of poor luminescence quenching of existing inorganic photochromic materials, and achieved a faster and more obvious color discoloration effect. It is suitable for fields such as intelligent optical switches and erasable optical information recording.
Patent Information
- Application Number
- CN202311118517.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-09-01
- Publication Date
- 2025-03-14
- Estimated Expiration
- 2043-09-01
AI Technical Summary
The existing inorganic photochromic materials have poor luminescence quenching, which limits their applications in fields such as intelligent optical switches and erasable optical information recording.
By doping Bi in BaySrGd4O8, a photochromic phosphor was prepared, and Bi was used as the center of discoloration to enhance oxygen vacancies and improve the discoloration effect.
A faster and more obvious color change effect is achieved, which helps to achieve more efficient color change and color rendering. By adjusting doped ions and concentration, the degree of color change can be adjusted, suitable for erasable optical information recording and intelligent optical switches.
Smart Images
Figure CN117106436B_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of luminescent materials, and in particular relates to a photochromic fluorescent powder and a preparation method thereof. Background Art
[0002] Photochromic phenomenon refers to the phenomenon that a certain compound A undergoes a specific chemical reaction when exposed to light of a certain wavelength and intensity, and another product B is obtained. Due to the different structure of product B, its absorption spectrum changes significantly, that is, the color changes. Under the irradiation of light of another wavelength or the action of heat, product B can return to the form of compound A. This kind of compound that can undergo reversible color change under the action of light is called a photochromic material. Based on the properties of the material, photochromic materials can be divided into two categories: organic photochromic materials and inorganic photochromic materials. However, organic photochromic materials generally have the disadvantages of slow color change reaction rate, easy aging, short color change duration, and poor thermal stability, which restricts the application of organic photochromic materials. Inorganic photochromic materials show characteristics that are significantly better than organic photochromic materials, such as fast color change reaction rate, strong anti-aging performance, long color change duration, and good thermal stability. It has great application potential in the fields of intelligent optical switches and erasable optical information recording.
[0003] The synthesis of inorganic photochromic materials with photoluminescence and photochromic properties by rare earth doping of specific compound matrices is currently the main method. However, compared with the upconversion emission type, the luminescence quenching degree of downconversion emission-based photochromic materials is still poor. Summary of the invention
[0004] The main purpose of the present invention is to provide a photochromic phosphor and a preparation method thereof.
[0005] To achieve the above object, the present invention provides a photochromic phosphor having a chemical formula of Ba y SrGd4O8:xBi; wherein y is the amount of Ba, 0.95≤y≤1, and x is the doping amount of Bi, 0≤x≤0.05.
[0006] A photochromic phosphor comprises the following raw materials in molar percentage: 50% Gd2O3, 23.75% to 25% BaCO3, 25% SrCO3, and 0.00 to 1.25% Bi2O3.
[0007] A method for preparing a photochromic fluorescent powder comprises the following steps: grinding and mixing Gd2O3, BaCO3, SrCO3 and Bi2O3 uniformly, calcining the mixture, and cooling the mixture to obtain a reversible photochromic fluorescent powder.
[0008] As a further improvement of the present invention, the calcination temperature is 1500-1600° C., the time is 4-20 hours, and the calcination atmosphere is air.
[0009] As a further improvement of the present invention, ethanol is added during the grinding, the volume ratio of ethanol to the total mass of the mixed powder is: 3-8 ml:3 g, and the grinding time is 10-60 min.
[0010] As a further improvement of the present invention, the cooling rate is 1-3°C / min.
[0011] The present invention also claims to protect the use of the photochromic phosphor in erasable optical information recording or intelligent optical switching.
[0012] The present invention is based on Ba y SrGd4O8 is the matrix carrier and Bi is the color-changing center. When the material is stimulated by light in a specific band, the matrix carrier absorbs energy, most of which will be converted into photons by the Gd luminescence center and released, and a small part will be captured by the oxygen vacancy defects in the matrix carrier, causing color change. When a certain amount of Bi is doped, the oxygen vacancy defects in the matrix carrier will increase, resulting in an enhanced color change effect.
[0013] The beneficial effects of the present invention are as follows: the present invention dopes Bi into Ba y SrGd4O8 achieves faster and more obvious color change, which helps to achieve more efficient color change and color display. In addition, by selecting different doping ions and doping concentrations and changing them, the color change degree can be adjusted, which can be used for erasable optical information recording and intelligent optical switches. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 The XRD diagrams of the photochromic phosphors prepared in Examples 1-6 of the present invention are shown.
[0015] Figure 2 This is a physical demonstration of the color change of the photochromic phosphor prepared in Example 1 of the present invention after being irradiated with 365nm ultraviolet light with a power density of 865 milliwatts per square centimeter for 60 seconds.
[0016] Figure 3 This is a diffuse reflection absorption spectrum of the photochromic phosphor prepared in Example 1 of the present invention when irradiated with 365 nm ultraviolet light at a power density of 865 mW / cm2 for 60 s.
[0017] Figure 4 This is a physical demonstration of the color change of the photochromic phosphor prepared in Example 2 of the present invention after being irradiated with 365nm ultraviolet light with a power density of 865 milliwatts per square centimeter for 60 seconds.
[0018] Figure 5This is a diffuse reflection absorption spectrum of the photochromic phosphor prepared in Example 2 of the present invention when irradiated with 365 nm ultraviolet light at a power density of 865 mW / cm2 for 60 s.
[0019] Figure 6 This is a physical demonstration of the color change of the photochromic phosphor prepared in Example 3 of the present invention after being irradiated with 365nm ultraviolet light with a power density of 865 milliwatts per square centimeter for 60 seconds.
[0020] Figure 7 This is a diffuse reflection absorption spectrum of the photochromic phosphor prepared in Example 3 of the present invention when irradiated with 365 nm ultraviolet light at a power density of 865 mW / cm2 for 60 s.
[0021] Figure 8 This is a physical demonstration of the color change of the reversible photochromic phosphor prepared in Example 4 of the present invention after being irradiated with 365nm ultraviolet light with a power density of 865 milliwatts per square centimeter for 60 seconds.
[0022] Fig. 9 This is the diffuse reflection absorption spectrum of the photochromic phosphor prepared in Example 4 of the present invention when irradiated with 365 nm ultraviolet light at a power density of 865 mW / cm2 for 60 s.
[0023] Fig.10 This is a physical demonstration of the color change of the photochromic phosphor prepared in Example 5 of the present invention after being irradiated with 365nm ultraviolet light with a power density of 865 milliwatts per square centimeter for 60 seconds.
[0024] Fig.11 This is the diffuse reflection absorption spectrum of the photochromic phosphor prepared in Example 5 of the present invention when irradiated with 365 nm ultraviolet light at a power density of 865 mW / cm2 for 60 s.
[0025] Fig.12 This is a physical demonstration of the color change of the photochromic phosphor prepared in Example 6 of the present invention after being irradiated with 365nm ultraviolet light with a power density of 865 milliwatts per square centimeter for 60 seconds.
[0026] Fig.13 This is the diffuse reflection absorption spectrum of the photochromic phosphor prepared in Example 6 of the present invention when irradiated with 365 nm ultraviolet light at a power density of 865 mW / cm2 for 60 s. DETAILED DESCRIPTION
[0027] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. In the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the art without making creative work are within the scope of protection of the present invention. Example 1
[0028] A photochromic phosphor comprises the following raw materials in molar percentage: 50% Gd2O3, 25% BaCO3, 25% SrCO3, and 0% Bi2O3.
[0029] A preparation method of a photochromic phosphor comprises the following steps: placing Gd2O3, BaCO3 and SrCO3 in an agate mortar, adding anhydrous ethanol according to the ratio of ethanol volume to powder mass = 5 ml:3 g, and grinding for 20 minutes to obtain a mixed powder; then transferring the mixed powder to a corundum crucible, placing the mixture in an air atmosphere at a temperature of 1500°C and sintering for 6 hours, and cooling the mixture to room temperature to obtain the photochromic phosphor; wherein the heating rate is 5°C / min; and the cooling rate is 3°C / min.
[0030] Depend on Figure 2-3 It can be seen that the photochromic phosphor prepared in this embodiment changes from white to gray-brown under ultraviolet light.
[0031] according to Figure 1 It can be seen that the present invention successfully prepared Ba y SrGd4O8:xBi material, and there is no impurity peak, indicating that the prepared material has high purity. Example 2
[0032] A photochromic phosphor comprises the following raw materials in molar percentage: 50% Gd2O3, 24.75% BaCO3, 25% SrCO3, and 0.25% Bi2O3.
[0033] A preparation method of a photochromic fluorescent powder comprises the following steps: placing Gd2O3, BaCO3, SrCO3 and Bi2O3 in an agate mortar, adding anhydrous ethanol according to the ratio of ethanol volume to powder mass = 5 ml:3 g, and grinding for 20 minutes to obtain a mixed powder; then transferring the mixed powder to a corundum crucible, placing it in an air atmosphere at a temperature of 1500° C. and sintering it for 6 hours, and cooling it to room temperature to obtain the photochromic fluorescent powder; wherein the heating rate is 5° C. / min; and the cooling rate is 3° C. / min.
[0034] Depend on Figure 4-5It can be seen that the photochromic phosphor prepared in this embodiment changes from white to gray-brown under ultraviolet light. Example 3
[0035] A photochromic phosphor comprises the following raw materials in molar percentage: 50% Gd2O3, 24.5% BaCO3, 25% SrCO3, and 0.5% Bi2O3.
[0036] A preparation method of a photochromic fluorescent powder comprises the following steps: placing Gd2O3, BaCO3, SrCO3 and Bi2O3 in an agate mortar, adding anhydrous ethanol according to the ratio of ethanol volume to powder mass = 5 ml:3 g, and grinding for 20 minutes to obtain a mixed powder; then transferring the mixed powder to a corundum crucible, placing it in an air atmosphere at a temperature of 1500° C. and sintering it for 6 hours, and cooling it to room temperature to obtain the photochromic fluorescent powder; wherein the heating rate is 5° C. / min; and the cooling rate is 3° C. / min.
[0037] Depend on Figure 6-7 It can be seen that the photochromic phosphor prepared in this embodiment changes from white to gray-brown under ultraviolet light. Example 4
[0038] A photochromic phosphor comprises the following raw materials in molar percentage: 50% Gd2O3, 24.25% BaCO3, 25% SrCO3, and 0.75% Bi2O3.
[0039] A preparation method of a photochromic fluorescent powder comprises the following steps: placing Gd2O3, BaCO3, SrCO3 and Bi2O3 in an agate mortar, adding anhydrous ethanol according to the ratio of ethanol volume to powder mass = 5 ml:3 g, and grinding for 20 minutes to obtain a mixed powder; then transferring the mixed powder to a corundum crucible, placing it in an air atmosphere at a temperature of 1500° C. and sintering it for 6 hours, and cooling it to room temperature to obtain the photochromic fluorescent powder; wherein the heating rate is 5° C. / min; and the cooling rate is 3° C. / min.
[0040] Depend on Figure 8-9 It can be seen that the photochromic phosphor prepared in this embodiment changes from white to gray-brown under ultraviolet light. Example 5
[0041] A photochromic phosphor comprises the following raw materials in molar percentage: 50% Gd2O3, 24% BaCO3, 25% SrCO3, and 1% Bi2O3.
[0042] A preparation method of a photochromic fluorescent powder comprises the following steps: placing Gd2O3, BaCO3, SrCO3 and Bi2O3 in an agate mortar, adding anhydrous ethanol according to the ratio of ethanol volume to powder mass = 5 ml:3 g, and grinding for 20 minutes to obtain a mixed powder; then transferring the mixed powder to a corundum crucible, placing it in an air atmosphere at a temperature of 1500° C. and sintering it for 6 hours, and cooling it to room temperature to obtain the photochromic fluorescent powder; wherein the heating rate is 5° C. / min; and the cooling rate is 3° C. / min.
[0043] Depend on Figure 10-11 It can be seen that the photochromic phosphor prepared in this embodiment changes from white to gray-brown under ultraviolet light. Example 6
[0044] A photochromic phosphor comprises the following raw materials in molar percentage: 50% Gd2O3, 23.75% BaCO3, 25% SrCO3, and 1.25% Bi2O3.
[0045] A preparation method of a photochromic fluorescent powder comprises the following steps: placing Gd2O3, BaCO3, SrCO3 and Bi2O3 in an agate mortar, adding anhydrous ethanol according to the ratio of ethanol volume to powder mass = 5 ml:3 g, and grinding for 20 minutes to obtain a mixed powder; then transferring the mixed powder to a corundum crucible, placing it in an air atmosphere at a temperature of 1500° C. and sintering it for 6 hours, and cooling it to room temperature to obtain the photochromic fluorescent powder; wherein the heating rate is 5° C. / min; and the cooling rate is 3° C. / min.
[0046] Depend on Figure 12-13 It can be seen that the photochromic phosphor prepared in this embodiment changes from white to gray-brown under ultraviolet light. Example 7
[0047] A photochromic phosphor comprises the following raw materials in molar percentage: 50% Gd2O3, 23.75% BaCO3, 25% SrCO3, and 2.5% Bi2O3.
[0048] A preparation method of a photochromic fluorescent powder comprises the following steps: placing Gd2O3, BaCO3, SrCO3 and Bi2O3 in an agate mortar, adding anhydrous ethanol according to the ratio of ethanol volume to powder mass = 5 ml:3 g, and grinding for 20 minutes to obtain a mixed powder; then transferring the mixed powder to a corundum crucible, placing it in an air atmosphere at a temperature of 1500° C. and sintering it for 6 hours, and cooling it to room temperature to obtain the photochromic fluorescent powder; wherein the heating rate is 5° C. / min; and the cooling rate is 3° C. / min.
[0049] Depend on Figure 12-13It can be seen that the photochromic phosphor prepared in this embodiment changes from white to gray-brown under ultraviolet light. Example 8
[0050] A photochromic phosphor comprises the following raw materials in molar percentage: 50% Gd2O3, 24.75% BaCO3, 25% SrCO3, and 0.25% Bi2O3.
[0051] A preparation method of a photochromic fluorescent powder comprises the following steps: placing Gd2O3, BaCO3, SrCO3 and Bi2O3 in an agate mortar, adding anhydrous ethanol according to the ratio of ethanol volume to powder mass = 8 ml:3 g, and grinding for 60 minutes to obtain a mixed powder; then transferring the mixed powder to a corundum crucible, placing it in an air atmosphere at a temperature of 1600°C and sintering it for 20 hours, and cooling it to room temperature to obtain the photochromic fluorescent powder; wherein the heating rate is 5°C / min; and the cooling rate is 1°C / min.
[0052] The photochromic phosphor prepared in this example changes from white to gray-brown under ultraviolet light. Example 9
[0053] A photochromic phosphor comprises the following raw materials in molar percentage: 50% Gd2O3, 24.75% BaCO3, 25% SrCO3, and 0.25% Bi2O3.
[0054] A preparation method of a photochromic fluorescent powder comprises the following steps: placing Gd2O3, BaCO3, SrCO3 and Bi2O3 in an agate mortar, adding anhydrous ethanol according to the ratio of ethanol volume to powder mass = 3 ml: 3 g, and grinding for 10 minutes to obtain a mixed powder; then transferring the mixed powder to a corundum crucible, placing it in an air atmosphere at a temperature of 1600°C and sintering it for 4 hours, and cooling it to room temperature to obtain the photochromic fluorescent powder; wherein the heating rate is 5°C / min; and the cooling rate is 1°C / min.
[0055] The photochromic phosphor prepared in this example changes from white to gray-brown under ultraviolet light.
[0056] Comparative Example 1
[0057] A photochromic phosphor comprises the following raw materials in molar percentage: 50% Gd2O3, 22% BaCO3, 25% SrCO3, and 3% Bi2O3.
[0058] The preparation method of the photochromic phosphor described in this comparative example is the same as that of Example 2.
[0059] The photochromic phosphor prepared in this comparative example changes from light yellow to gray brown under ultraviolet light, but requires a longer time under ultraviolet light to achieve color change.
[0060] Comparative Example 2
[0061] A photochromic phosphor comprises the following raw materials in molar percentage: 50% Gd2O3, 24.75% BaCO3, 25% SrCO3, and 0.25% Bi2O3.
[0062] A preparation method of a photochromic phosphor comprises the following steps: Gd2O3, BaCO3, SrCO3 and Bi2O3 are placed in an agate mortar and ground for 20 minutes to obtain a mixed powder; then the mixed powder is transferred to a corundum crucible, placed in an air atmosphere at a temperature of 1500°C and sintered for 6 hours, and cooled to room temperature to obtain the photochromic phosphor; wherein the heating rate is 5°C / min; and the cooling rate is 3°C / min.
[0063] The photochromic phosphor prepared in this comparative example changes from white to gray-brown under ultraviolet light, but requires a longer period of time under ultraviolet light to achieve color change.
[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.
Claims
1. A photochromic phosphor, characterized in that: Its chemical formula is Ba y SrGd4O8:xBi; wherein y is the amount of Ba, 0.95≤y<1, and x is the doping amount of Bi, 0<x≤0.
05.
2. The photochromic phosphor according to claim 1, characterized in that: The invention comprises raw materials with the following molar percentages: 50% Gd2O3, 23.75% to 25% BaCO3, 25% SrCO3, and 0.00 to 1.25% Bi2O3.
3. The method for preparing the photochromic phosphor according to claim 1 or 2, characterized in that: The method comprises the following steps: grinding and mixing Gd2O3, BaCO3, SrCO3 and Bi2O3 uniformly, calcining the mixture, and obtaining reversible photochromic fluorescent powder after cooling.
4. The method for preparing the photochromic phosphor according to claim 3, characterized in that: The calcination temperature is 1500-1600°C, the time is 4-20 hours, and the calcination atmosphere is air.
5. The method for preparing the photochromic phosphor according to claim 3, characterized in that: Ethanol is added during the grinding, the volume ratio of ethanol to the total mass of the mixed powder is: 3-8 ml:3 g, and the grinding time is 10-60 min.
6. The method for preparing the photochromic phosphor according to claim 3, characterized in that: The cooling rate is 1~3℃ / min.