A chromium ion-doped phosphate photoluminescent material, a preparation method and application thereof

Abstract

The application discloses a chromium ion doped phosphate photoluminescence material and a preparation method and application thereof, and aims to provide a novel chromium ion doped phosphate photoluminescence material, a chemical structural formula of which is CaHf 4‑x (PO4)6:xCr 3+ , 0 < x <= 0.09. The chromium ion doped phosphate photoluminescence material can produce long-wavelength and wide-band near-infrared emission under blue light excitation, can cover C-H bond absorption bands (908nm) and O-H bond absorption bands (980nm), is used for judging water content in an organic solvent, and can realize rapid, non-contact and non-destructive judgment of the water content in the organic solvent. The preparation method is that a calcium-containing compound, a hafnium-containing compound, ammonium dihydrogen phosphate and a chromium-containing compound are mixed, are baked at 1150 DEG C to 1350 DEG C for 4h to 6h in an air atmosphere, are naturally cooled, are ground, and the chromium ion doped phosphate photoluminescence material is obtained. The preparation method is simple in operation and environment-friendly, the chromium ion doped phosphate photoluminescence material is easy to be prepared on a large scale, and belongs to the technical field of inorganic photoluminescence materials.

Description

TECHNICAL FIELD

[0001] The application discloses a luminescent material, and also discloses a preparation method and application of the chromium ion doped phosphate photoluminescent material, and belongs to the technical field of inorganic photoluminescent materials. BACKGROUND

[0002] Photoluminescent materials are materials that can absorb light energy of a specific wavelength and emit photons of a different wavelength through a radiative process. The photoluminescence phenomenon typically involves the transition of electrons from a ground state to an excited state, and the release of energy when returning to the ground state. Due to their unique optical properties, photoluminescent materials have wide application prospects in night vision lighting, medical imaging, biological tissue analysis, industrial detection, plant growth, and many other fields. With continuous research, although significant progress has been made in the field of photoluminescent materials, there are still many challenges. For example, how to improve the quantum yield of the material, broaden the emission wavelength range, enhance the environmental stability, and simplify the preparation process. In addition, to meet the needs of specific applications, the development of new photoluminescent materials with special properties is still a research hotspot.

[0003] In the chemical industry, there is often a small amount of water in some organic solvents, which can have a significant impact on the production process. The presence of trace amounts of water in organic solutions as raw materials not only reduces the purity of the product, affecting product quality and performance, but also can cause side reactions and produce impurities, reducing reaction efficiency and yield. In addition, water can cause corrosion of equipment, affecting the service life of equipment, increasing maintenance costs and safety risks. Therefore, to reduce the impact of trace amounts of water in organic solvents, it is necessary to detect the purity of the solvent more quickly and accurately, and to implement it in each link of production and storage. At present, there is a lack of a rapid, non-contact and non-destructive detection system for the detection of trace amounts of water in organic solvents, which can accurately determine the water content and provide timely feedback to control the production process. SUMMARY

[0004] To solve the above problems, the technical problem to be solved by the present application is to provide a new chromium ion doped phosphate photoluminescent material. The chromium ion doped phosphate photoluminescent material can produce long-wavelength and wide-band near-infrared emission under blue light excitation, covering the C-H bond absorption band (908 nm) and the O-H bond absorption band (980 nm).

[0005] The second technical problem to be solved by the present application is to provide a preparation method for a new chromium ion doped phosphate photoluminescent material. The preparation method is simple to operate and environmentally friendly, making it easy to mass-produce chromium ion doped phosphate photoluminescent materials.

[0006] The third technical problem of the present application is to use the above-mentioned chromium ion doped phosphate photoluminescence material to determine the moisture content in the organic solvent, so as to realize the rapid, non-contact and non-destructive determination of the moisture content in the organic solvent.

[0007] To this end, the first technical solution provided by the present application is as follows:

[0008] A chromium ion doped phosphate photoluminescence material, the chemical structural formula of which is CaHf 4-x (PO4)6:xCr 3+ , 0 < x ≤ 0.09.

[0009] The second technical solution provided by the present application is a preparation method of the above-mentioned chromium ion doped phosphate photoluminescence material, which comprises the following steps in sequence: mixing a calcium-containing compound, a hafnium-containing compound, ammonium dihydrogen phosphate and a chromium-containing compound, calcining in an air atmosphere at 1150-1350°C for 4-6 hours, naturally cooling the calcined product and then grinding to obtain the chromium ion doped phosphate photoluminescence material.

[0010] The molar ratio of the calcium-containing compound, the hafnium-containing compound, the ammonium dihydrogen phosphate and the chromium-containing compound is 1:3.91-3.99:6:0.01-0.09.

[0011] Further, in the above-mentioned preparation method of the chromium ion doped phosphate photoluminescence material, the calcining temperature is 1230-1280°C.

[0012] Further, in the above-mentioned preparation method of the chromium ion doped phosphate photoluminescence material, the calcining time is 5 hours.

[0013] Further, in the above-mentioned preparation method of the chromium ion doped phosphate photoluminescence material, the molar ratio of the calcium-containing compound, the hafnium-containing compound, the ammonium dihydrogen phosphate and the chromium-containing compound is 1:3.95-3.99:6:0.03-0.07.

[0014] Further, in the above-mentioned preparation method of the chromium ion doped phosphate photoluminescence material, the calcium-containing compound is calcium carbonate; the hafnium-containing compound is hafnium oxide; and the chromium-containing compound is chromium oxide.

[0015] Further, in the above-mentioned preparation method of the chromium ion doped phosphate photoluminescence material, after mixing the calcium-containing compound, the hafnium-containing compound, the ammonium dihydrogen phosphate and the chromium-containing compound, the method further comprises the following step before calcining in the air atmosphere: grinding the mixture obtained by mixing the calcium-containing compound, the hafnium-containing compound, the ammonium dihydrogen phosphate and the chromium-containing compound to obtain a uniform mixed solid powder.

[0016] Further, the preparation method of the chromium ion doped phosphate photoluminescence material, the roasting is carried out at the temperature increasing rate of 5℃ / min-8℃ / min, preferably at the temperature increasing rate of 6℃ / min.

[0017] The last technical solution provided by the present application is that the chromium ion doped phosphate photoluminescence material is used for detecting the moisture content in the organic solvent.

[0018] The present application further provides a fluorescent powder conversion type LED of the luminescent material, epoxy resin and the CaHf 3.95 (PO4)6:0.05Cr 3+ compound are weighed according to the mass ratio of 2:1, and are fully mixed and stirred in a stirrer for 10 minutes to obtain a uniform fluorescent powder silica gel mixture; the obtained mixture is uniformly coated on the surface of the blue light LED chip by using a dispenser, the coated blue light LED chip is placed in an oven, and is heated to 100℃ at the temperature increasing rate of 2℃ / min, and is cured for 1 hour in an air atmosphere, and after being cooled to room temperature, the fluorescent powder conversion type LED of the luminescent material with the CaHf 3.95 (PO4)6:0.05Cr 3+ compound as the luminescent material is obtained.

[0019] Compared with the prior art, the technical solution provided by the present application has the following technical advantages:

[0020] 1. The chromium ion doped phosphate photoluminescence material provided by the present application has good chemical stability, can produce long-wavelength and wide-band near-infrared emission under blue light excitation, and this photoluminescence performance enables the material to be well combined with a blue light LED chip, and to be used in the fields of night vision lighting, food detection and medical imaging.

[0021] 2. The preparation method of the new chromium ion doped phosphate photoluminescence material is simple in operation and environmentally friendly, and enables the chromium ion doped phosphate photoluminescence material to be easily prepared on a large scale. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 The scanning electron microscope image of the chromium ion doped phosphate photoluminescence material prepared in the present application example 1 is shown in the figure;

[0023] Figure 2 The X-ray diffraction pattern of the different chromium ion doping concentration samples of the chromium ion doped phosphate photoluminescence material prepared in the present application example 1 is shown in the figure;

[0024] Figure 3 The diffuse reflection spectrum of the chromium ion doped phosphate photoluminescence material prepared in the present application example 1 under blue light excitation is shown in the figure.

[0025] Figure 4 Fluorescence spectrum of the chromium ion doped phosphate photoluminescence material prepared in Embodiment 1 of the present application under blue light excitation;

[0026] Figure 5 Near-infrared transmission spectrum of different concentrations of methanol-water mixture under irradiation of the phosphor converted LED prepared in Embodiment 2 of the present application;

[0027] Figure 6 Near-infrared transmission spectrum of different concentrations of ethanol-water mixture under irradiation of the phosphor converted LED prepared in Embodiment 2 of the present application. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be described clearly and completely 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 those skilled in the art without creative work fall within the protection scope of the present application.

[0029] Embodiment 1

[0030] CaCO3, HfO2, NH4H2PO4 and Cr2O3 were weighed according to the molar ratio of 1:3.95:6:0.05, mixed and ground for 30 minutes to obtain a uniform mixed solid powder. The obtained mixed solid powder was loaded into a corundum crucible and put into a high-temperature furnace, heated to 500℃ at a heating rate of 5℃ / min, and baked for 2h under air atmosphere. After the baked product was naturally cooled to room temperature, it was taken out and ground again. The ground mixed solid powder was again loaded into a corundum crucible, covered and put into a high-temperature furnace, heated to 1250℃ at a heating rate of 6℃ / min, baked for 5h under air atmosphere, and after the baked product was naturally cooled to room temperature, it was taken out and ground again to obtain a chromium ion doped phosphate photoluminescence material with the chemical structural formula of CaHf 3.95 (PO4)6:0.05Cr 3+ .

[0031] Please refer to Figure 1 and Figure 2 , which are the scanning electron microscope images and X-ray diffraction patterns of samples with different concentrations of the chromium ion doped phosphate photoluminescence material prepared in Embodiment 1 of the present application, respectively. The results show that the chromium ion doped phosphate photoluminescence material prepared in Embodiment 1 of the present application has no additional X-ray diffraction peaks corresponding to impurity phases, and a pure phase CaHf 4-x (PO4)6:xCr 3+ compound is successfully synthesized.

[0032] Please refer toFigure 3 and Figure 4 The diffuse reflectance spectrum and fluorescence spectrum of the chromium ion doped phosphate photoluminescence material prepared in Example 1 of the present application under blue light excitation are shown in Figures 2 and 3, respectively. The results show that the chromium ion doped phosphate photoluminescence material prepared in Example 1 of the present application has an absorption peak at 472 nm and 720 nm, respectively, and can produce long wavelength (914 nm) and wide band (FWHM = 160 nm) near-infrared emission under light excitation at a wavelength of 472 nm.

[0033] Example 2

[0034] CaCO3, HfO2, NH4H2PO4 and Cr2O3 were weighed in a molar ratio of 1:3.99:6:0.01, mixed thoroughly and ground for 30 minutes to obtain a uniform mixed solid powder. The obtained mixed solid powder was placed in a corundum crucible and put into a high temperature furnace, heated to 500°C at a heating rate of 5°C / min, and calcined under air atmosphere for 2 h. After the calcined product was naturally cooled to room temperature, it was taken out and ground again. The obtained mixed solid powder after grinding was again placed in a corundum crucible, put into a high temperature furnace after being covered, heated to 1150°C at a heating rate of 5°C / min, and calcined under air atmosphere for 6 h. After the calcined product was naturally cooled to room temperature, it was taken out and ground again to obtain a chromium ion doped phosphate photoluminescence material with a chemical structural formula of CaHf 3.99 (PO4)6:0.01Cr 3+ .

[0035] Example 3

[0036] CaCO3, HfO2, NH4H2PO4 and Cr2O3 were weighed in a molar ratio of 1:3.97:6:0.03, mixed thoroughly and ground for 30 minutes to obtain a uniform mixed solid powder. The obtained mixed solid powder was placed in a corundum crucible and put into a high temperature furnace, heated to 500°C at a heating rate of 5°C / min, and calcined under air atmosphere for 2 h. After the calcined product was naturally cooled to room temperature, it was taken out and ground again. The obtained mixed solid powder after grinding was again placed in a corundum crucible, put into a high temperature furnace after being covered, heated to 1230°C at a heating rate of 6°C / min, and calcined under air atmosphere for 5 h. After the calcined product was naturally cooled to room temperature, it was taken out and ground again to obtain a chromium ion doped phosphate photoluminescence material with a chemical structural formula of CaHf 3.97 (PO4)6:0.03Cr 3+ .

[0037] Example 4

[0038] CaCO3, HfO2, NH4H2PO4 and Cr2O3 were weighed in a molar ratio of 1:3.93:6:0.07, and the mixture was thoroughly mixed and ground for 30 minutes to obtain a uniform mixed solid powder. The obtained mixed solid powder was placed in a corundum crucible, placed in a high-temperature furnace, heated to 500°C at a heating rate of 5°C / min, and kept warm for 2 hours in an air atmosphere for calcination. After the calcined product naturally cooled to room temperature, it was taken out and ground again. The mixed solid powder obtained after grinding was placed in a corundum crucible again, covered and placed in a high-temperature furnace, heated to 1280°C at a heating rate of 7°C / min, and kept warm for 5 hours in an air atmosphere for calcination. After the calcined product naturally cooled to room temperature, it was taken out and ground again to obtain a chemical formula of CaHf 3.93 (PO4)6:0.07Cr 3+ Chromium ion-doped phosphate photoluminescent material.

[0039] Example 5

[0040] CaCO3, HfO2, NH4H2PO4 and Cr2O3 were weighed in a molar ratio of 1:3.91:6:0.09, and the mixture was thoroughly mixed and ground for 30 minutes to obtain a uniform mixed solid powder. The obtained mixed solid powder was placed in a corundum crucible, placed in a high-temperature furnace, heated to 500°C at a heating rate of 5°C / min, and kept warm for 2 hours in an air atmosphere for calcination. After the calcined product naturally cooled to room temperature, it was taken out and ground again. The mixed solid powder obtained after grinding was again placed in a corundum crucible, covered and placed in a high-temperature furnace, heated to 1350°C at a heating rate of 8°C / min, and kept warm for 4 hours in an air atmosphere for calcination. After the calcined product naturally cooled to room temperature, it was taken out and ground again to obtain a chemical structure of CaHf 3.91 (PO4)6:0.09Cr 3+ Chromium ion-doped phosphate photoluminescent material.

[0041] Example 6

[0042] Epoxy resin and CaHf prepared in Example 1 were weighed in a mass ratio of 2:1. 3.95 (PO4)6:0.05Cr 3+ The compound was placed in a blender and thoroughly mixed for 10 minutes to obtain a uniform phosphor silica gel mixture. The obtained mixture was evenly coated on the surface of the blue LED chip using a dispenser to ensure a uniform thickness of the phosphor layer. The coated blue LED chip was placed in an oven and heated to 100°C at a heating rate of 2°C / min. The mixture was kept warm for 1 hour in an air atmosphere for curing. After cooling to room temperature, a CaHf 3.95 (PO4)6:0.05Cr 3+The compound is a phosphor converted LED.

[0043] The specific test method is as follows:

[0044] A 1cm-thick quartz cuvette was used to take 1ml of pure water, 1ml of anhydrous methanol, and 1ml of a methanol-water mixture with a concentration ratio of 2:8, 4:6, 6:4, and 8:2, respectively. The phosphor converted LED prepared in Example 6 was fixed in the straight line direction of the near-infrared probe, and the quartz cuvettes containing 1ml of pure water, 1ml of anhydrous methanol solution, and 1ml of the above-mentioned concentration methanol-water mixture were placed in the straight line direction of the phosphor converted LED prepared in Example 6 and the near-infrared probe. A direct current power supply was used to connect the phosphor converted LED prepared in Example 6, and the transmission light intensity was collected using the near-infrared probe after the power supply was turned on. The transmission spectrum collected is shown in Figure 5 .

[0045] A 1cm-thick quartz cuvette was used to take 1ml of pure water, 1ml of anhydrous ethanol, and 1ml of an ethanol-water mixture with a concentration ratio of 2:8, 4:6, 6:4, and 8:2, respectively. The phosphor converted LED prepared in Example 6 was fixed in the straight line direction of the near-infrared probe, and the quartz cuvettes containing 1ml of pure water, 1ml of anhydrous ethanol solution, and 1ml of the above-mentioned concentration ethanol-water mixture were placed in the straight line direction of the phosphor converted LED prepared in Example 6 and the near-infrared probe. A direct current power supply was used to connect the phosphor converted LED prepared in Example 6, and the transmission light intensity was collected using the near-infrared probe after the power supply was turned on. The transmission spectrum collected is shown in Figure 6 .

[0046] Please refer to Figure 5 and Figure 6 , which are the near-infrared transmission spectra of different concentrations of methanol-water mixture and ethanol-water mixture under the irradiation of the phosphor converted LED prepared in Example 6 of the present application. The results show that under the irradiation of the phosphor converted LED prepared in Example 6 of the present application, as the concentration of pure water in the methanol-water mixture or the ethanol-water mixture increases, a clear dip is formed in the 925nm-1025nm band, and especially at the O-H bond absorption band (980nm), the transmission light intensity can be significantly observed to decrease with the increase of the concentration of pure water.

Claims

1. An application of a chromium ion-doped phosphate photoluminescent material, characterized in that: The chromium ion doped phosphate photoluminescent material is combined with a blue light LED chip to prepare a phosphor conversion LED for detecting the moisture content in an organic solvent. The chemical structure of the chromium ion doped phosphate photoluminescent material is CaHf 4-x (PO4)6: xCr 3+ , 0<x≤0.

09.

2. The use of a chromium ion-doped phosphate photoluminescent material according to claim 1, characterized in that: The method for preparing the chromium ion-doped phosphate photoluminescent material comprises the following steps: mixing a calcium-containing compound, a hafnium-containing compound, ammonium dihydrogen phosphate, and a chromium-containing compound; calcining the mixture at 1150° C. to 1350° C. for 4 to 6 hours in an air atmosphere; naturally cooling the calcined product and then grinding the mixture to obtain the chromium ion-doped phosphate photoluminescent material; The molar ratio of the calcium-containing compound, the hafnium-containing compound, the ammonium dihydrogen phosphate and the chromium-containing compound is 1:3.91-3.99:6:0.01-0.

09.

3. The use of a chromium ion-doped phosphate photoluminescent material according to claim 2, characterized in that: The calcination temperature is 1230°C to 1280°C.

4. The use of a chromium ion-doped phosphate photoluminescent material according to claim 2, characterized in that: The roasting time is 5 hours.

5. The use of a chromium ion-doped phosphate photoluminescent material according to claim 2, characterized in that: The molar ratio of the calcium-containing compound, the hafnium-containing compound, the ammonium dihydrogen phosphate and the chromium-containing compound is 1:3.95-3.99:6:0.03-0.

07.

6. The use of a chromium ion-doped phosphate photoluminescent material according to claim 2, characterized in that: The calcium-containing compound is calcium carbonate; the hafnium-containing compound is hafnium oxide; and the chromium-containing compound is chromium oxide.

7. The use of a chromium ion-doped phosphate photoluminescent material according to claim 2, characterized in that: After the calcium-containing compound, hafnium-containing compound, ammonium dihydrogen phosphate and chromium-containing compound are mixed and before the calcination in air atmosphere, the method further comprises grinding the mixture obtained by mixing the calcium-containing compound, hafnium-containing compound, ammonium dihydrogen phosphate and chromium-containing compound to obtain a uniform mixed solid powder.

8. The use of a chromium ion-doped phosphate photoluminescent material according to claim 2, characterized in that: The calcination is carried out at a heating rate of 5°C / min to 8°C / min.

9. The use of a chromium ion-doped phosphate photoluminescent material according to claim 1, characterized in that: The phosphor conversion LED is prepared by the following method: epoxy resin and CaHf are weighed in a mass ratio of 2:

1. 3.95 (PO4)6: 0.05Cr 3+ The compound was placed in a blender and thoroughly mixed for 10 minutes to obtain a uniform phosphor silica gel mixture; the obtained mixture was evenly coated on the surface of the blue LED chip using a dispenser, and the coated blue LED chip was placed in an oven and heated to 100°C at a heating rate of 2°C / min. The mixture was kept warm for 1 hour in an air atmosphere for curing, and then cooled to room temperature to obtain a CaHf 3.95 (PO4)6: 0.05Cr 3+ Phosphor-converted LEDs with compounds as luminescent materials.

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