Vanadium ion-doped phosphate-based luminescent material, and preparation method and application thereof

Abstract

The application discloses a vanadium ion doped phosphate-based luminescent material, a preparation method and application thereof, and a chemical general formula of the luminescent material is Ca9AlP 7(1‑x) O 28 :xV 5+ , wherein x=0.005-0.04. The luminescent material can generate wideband emission from 400nm to 600nm under excitation of 300nm ultraviolet light, and the peak position is near 480nm. The vanadium ion doped phosphate-based luminescent material emits a spectrum with an integral intensity Omega, which changes as a function of temperature T, Omega=1.457*exp(-T / 145.367)-0.169, and the relative sensitivity obtained at 250 DEG C reaches 2.03% DEG C ‑1 . The material has application potential in the field of optical thermometers and the like. In addition, the luminescent material has the advantages of simple preparation method, low cost and the like.

Description

Technical Field

[0001] This invention relates to the field of luminescent materials, and more particularly to a vanadium ion-doped phosphate-based luminescent material, its preparation method, and its application. Background Technology

[0002] Transition metal ion-activated luminescent materials possess rich spectra and excellent luminescent properties, and their activated luminescent materials have already achieved widespread applications in the visible and infrared bands. Currently, related research mainly focuses on Cr... 3+ Mn 2+ While plasma luminescent materials have been widely studied, research on vanadium (V) ion-activated luminescent materials is limited. Furthermore, most reports only pertain to vanadates, and their luminescent properties are not ideal, with few applications of these materials. Therefore, this invention proposes a novel approach of doping non-vanadate compounds with V ions to improve V ion luminescence performance and enrich the quantity and variety of V ion-activated luminescent materials.

[0003] Traditional temperature sensing elements utilize physical effects such as thermal expansion and thermal resistance for contact temperature measurement, which suffers from drawbacks such as slow response and narrow temperature measurement range. In contrast, optical thermometers, which detect temperature by detecting light signals, offer advantages such as fast response and a wide temperature measurement range. They hold promise as a replacement for traditional thermometers, enabling accurate temperature measurement in complex environments such as electronic components, biological tissues, corrosive conditions, earthquakes, and fires. However, the relative sensitivity of traditional temperature measurement methods based on the luminescence of trivalent rare-earth ions decays rapidly at higher temperatures (e.g., Chinese patent CN 109468133 A, 2019-03-15), with a relative sensitivity of less than 1.5%℃ at 200℃. -1 This leads to drawbacks in existing optical thermometers, such as large errors and high costs. Therefore, the development of novel luminescent materials for thermometers with high sensitivity and the ability to replace rare earth elements is of great significance. Summary of the Invention

[0004] The main objective of this invention is to provide a vanadium ion-doped phosphate-based luminescent material whose emission spectrum integral intensity varies with temperature, as well as its preparation method and application.

[0005] To achieve the above objectives, the present invention provides a vanadium ion-doped phosphate-based luminescent material with the chemical formula Ca9AlP 7(1-x) O 28 :xV 5+ , where x represents the substitution rate, x = 0.005 to 0.04.

[0006] The present invention also provides the application of the above-mentioned vanadium ion-doped phosphate-based luminescent material in the preparation of optical thermometers.

[0007] Furthermore, the optical thermometer references the following: when the vanadium ion-doped phosphate-based luminescent material is excited by 300 nm ultraviolet light, the integral intensity Ω of its emission spectrum varies with temperature T as a function Ω = 1.457*exp(-T / 145.367)-0.169.

[0008] The present invention also provides a method for preparing the above-mentioned vanadium ion-doped phosphate-based luminescent material, wherein the material is prepared by calcining a mixture of calcium-containing compounds, aluminum-containing compounds, phosphorus-containing compounds and vanadium-containing compounds.

[0009] Furthermore, the calcium-containing compound is any one or a combination of two or more compounds such as calcium oxides, carbonates, nitrates, hydroxides, and chlorides.

[0010] Furthermore, the aluminum-containing compound is any one or a combination of two or more compounds such as aluminum oxides, carbonates, nitrates, hydroxides, and chlorides.

[0011] Furthermore, the phosphorus-containing compound is any one or a combination of two or more compounds such as phosphorus oxides, phosphates, and hydrides.

[0012] Furthermore, the vanadium-containing compound is any one or a combination of two or more compounds such as vanadium oxides, halides, carbides, hydroxides, and chlorides.

[0013] Further, it includes the following steps: according to the general chemical formula Ca9AlP 7(1-x) O 28 :xV 5+ The raw materials containing calcium, aluminum, phosphorus and vanadium were weighed and mixed according to the molar ratio of Ca, Al, P and V. The mixture was then placed in a high-temperature air atmosphere for firing. After cooling in the furnace, the vanadium ion-doped phosphate-based luminescent material was obtained.

[0014] Furthermore, the firing process includes first holding the mixture at 700–800℃ for 4–6 hours, grinding it evenly, and then holding it at 1100–1200℃ for 3–5 hours.

[0015] The beneficial effects of this invention are reflected in:

[0016] 1. The vanadium ion-doped phosphate-based luminescent material provided by this invention has a composition close to Ca9AlP7O 28 The compound is the matrix, V 5+ This method of activating ions has not been reported before; after ultraviolet light excitation, this material can emit in the wavelength range of 400-600 nm, with the highest emission peak located near 480 nm, which is a very strong emission spectrum.

[0017] 2. The vanadium ion-doped phosphate-based luminescent material provided by this invention exhibits only 3.75% of its luminescence intensity after being excited by an ultraviolet light source at 300°C, compared to that at room temperature. Furthermore, according to the formula... (S R (Relative sensitivity, Ω: luminescence integral intensity, T: temperature) The relative sensitivity obtained at 250℃ reaches 2.03%℃. -1 Therefore, the vanadium ion-activated phosphate-based luminescent material provided by this invention can measure temperature based on the change of the integrated intensity of the emission spectrum with temperature, and can be applied to the field of luminescent thermometry;

[0018] 3. The vanadium ion-doped phosphate-based luminescent material provided by this invention uses vanadium ions instead of rare earth ions as the activating ions. Compared with rare earth ions, vanadium ions have a lower raw material price, which can reduce production costs.

[0019] 4. The method for preparing vanadium ion-doped phosphate-based luminescent materials provided by the present invention is carried out in an air atmosphere or an oxygen atmosphere, without the need for a reducing atmosphere, which can reduce the requirements and costs of production equipment. Attached Figure Description

[0020] Figure 1 The vanadium ion-doped phosphate-based luminescent materials prepared in Examples 1-5 and Comparative Example 1 of this invention, and Ca9AlP7O 28 The XRD (X-ray diffraction) pattern corresponding to the standard card.

[0021] Figure 2 The excitation spectra of the vanadium ion-doped phosphate-based luminescent materials prepared in Examples 1-5 and Comparative Example 1 of this invention are shown at room temperature, with a monitoring wavelength of 480 nm.

[0022] Figure 3 The emission spectra of the vanadium ion-doped phosphate-based luminescent materials prepared in Examples 1-5 and Comparative Example 1 of this invention are shown at room temperature, with an excitation wavelength of 300 nm.

[0023] Figure 4 The excitation and emission spectra of the vanadium ion-doped phosphate-based luminescent material prepared in Example 3 of this invention are shown at room temperature.

[0024] Figure 5 The excitation spectrum of the vanadium ion-doped phosphate-based luminescent material prepared in Example 3 of the present invention is shown in the temperature range of 25–300 °C.

[0025] Figure 6 The emission spectrum of the vanadium ion-doped phosphate-based luminescent material prepared in Example 3 of the present invention is shown in the temperature range of 25–300 °C.

[0026] Figure 7The graph shows the integral intensity of the emission spectrum of the vanadium ion-doped phosphate-based luminescent material prepared in Example 3 of this invention as a function of temperature and the relationship between the points and the fitted function. The points represent experimental measurements, and the curves represent the fitted function values.

[0027] Figure 8 The temperature sensitivity curve of the vanadium ion-doped phosphate-based luminescent material prepared in Example 3 of this invention is shown. Detailed Implementation

[0028] To enable those skilled in the art to more clearly understand the technical solutions described in this invention, the following embodiments are provided for illustration. It should be noted that the following embodiments do not constitute a limitation on the scope of protection claimed by this invention.

[0029] Unless otherwise specified, the raw materials, reagents or devices used in the following examples are available from conventional commercial sources or can be obtained by existing known methods.

[0030] Example 1

[0031] Preparation of vanadium ion-doped phosphate-based luminescent materials

[0032] The chemical formula of the vanadium ion-doped phosphate-based luminescent material prepared in this embodiment is: Ca9AlP 6.965 O 28 0.005V 5+ The preparation method is as follows:

[0033] According to the above chemical formula molar ratio, weigh out the raw materials CaCO3, Al2O3, NH4H2PO4, and V2O5 and place them in an agate mortar. Grind them into a uniformly mixed powder, then place the powder in an alumina crucible. First, keep the temperature at 700℃ for 4 hours, grind it evenly, and then keep it at 1100℃ for 3 hours. The entire firing process is carried out in an air atmosphere. Afterward, cool the product to room temperature with the furnace. The product is then ground and pulverized to obtain Ca9AlP. 6.965 O 28 0.005V 5+ Luminescent materials.

[0034] The luminescent material in this embodiment is Ca9AlP. 6.965 O 28 0.005V 5+ The XRD pattern can be found Figure 1 The emission spectrum is shown below. Figure 3 .

[0035] Depend on Figure 1 It can be seen that the X-ray diffraction peaks of the luminescent material in this embodiment are consistent with those of the standard card, and no other impurities are observed.

[0036] Depend on Figure 3It can be seen that the emission peak of the luminescent material in this embodiment is located near 480nm, and the luminescence intensity at the highest peak of the emission peak is about 121 counts.

[0037] Example 2

[0038] Preparation of vanadium ion-doped phosphate-based luminescent materials

[0039] The chemical formula of the vanadium ion-doped phosphate-based luminescent material prepared in this embodiment is: Ca9AlP 6.93 O 28 0.01V 5 + The preparation method is as follows:

[0040] According to the above chemical formula molar ratio, weigh out the raw materials CaCO3, Al2O3, NH4H2PO4, and V2O5 and place them in an agate mortar. Grind them into a uniformly mixed powder, then place the powder in an alumina crucible. First, keep the temperature at 700℃ for 6 hours, grind it evenly, and then keep it at 1100℃ for 5 hours. The entire firing process is carried out in an air atmosphere. Afterward, cool the furnace to room temperature. The product is then ground and pulverized to obtain Ca9AlP. 6.93 O 28 0.01V 5+ Luminescent materials.

[0041] The luminescent material in this embodiment is Ca9AlP. 6.93 O 28 0.01V 5+ The XRD pattern can be found Figure 1 The emission spectrum is shown below. Figure 3 .

[0042] Depend on Figure 1 It can be seen that the X-ray diffraction peaks of the luminescent material in this embodiment are consistent with those of the standard card, and no other impurities are observed.

[0043] Depend on Figure 3 It can be seen that the emission peak of the luminescent material in this embodiment is located near 480nm, and the luminescence intensity at the highest peak of the emission peak is about 10¹² count intensity.

[0044] Example 3

[0045] Preparation of vanadium ion-doped phosphate-based luminescent materials

[0046] The chemical formula of the vanadium ion-doped phosphate-based luminescent material prepared in this embodiment is: Ca9AlP 6.86 O 28 0.02V 5 + The preparation method is as follows:

[0047] According to the above chemical formula molar ratio, weigh out the raw materials CaCO3, Al2O3, NH4H2PO4, and V2O5 and place them in an agate mortar. Grind them into a uniformly mixed powder, then place the powder in an alumina crucible. First, keep the temperature at 750℃ for 5 hours, grind it evenly, and then keep it at 1150℃ for 4 hours. The entire firing process is carried out in an air atmosphere. Afterward, cool the product to room temperature with the furnace. The product is then ground and pulverized to obtain Ca9AlP. 6.86 O 28 0.02V 5+ Luminescent materials.

[0048] The luminescent material in this embodiment is Ca9AlP. 6.86 O 28 0.02V 5+ The XRD pattern can be found Figure 1 The emission spectrum is shown below. Figure 3 .

[0049] Depend on Figure 1 It can be seen that the X-ray diffraction peaks of the luminescent material in this embodiment are consistent with those of the standard card, and no other impurities are observed.

[0050] Depend on Figure 3 It can be seen that the emission peak of the luminescent material in this embodiment is located near 480nm, and the luminescence intensity at the highest peak of the emission peak is about 1256 counts.

[0051] Example 4

[0052] Preparation of vanadium ion-doped phosphate-based luminescent materials

[0053] The chemical formula of the vanadium ion-doped phosphate-based luminescent material prepared in this embodiment is: Ca9AlP 6.79 O 28 0.03V 5 + The preparation method is as follows:

[0054] According to the above chemical formula molar ratio, weigh out the raw materials CaCO3, Al2O3, NH4H2PO4, and V2O5 and place them in an agate mortar. Grind them into a uniformly mixed powder, then place the powder in an alumina crucible. First, keep the temperature at 800℃ for 4 hours, grind it evenly, and then keep it at 1200℃ for 3 hours. The entire firing process is carried out in an air atmosphere. Afterward, cool the furnace to room temperature. The product is then ground and pulverized to obtain Ca9AlP. 6.79 O 28 0.03V 5+ Luminescent materials.

[0055] The luminescent material in this embodiment is Ca9AlP. 6.79 O 28 0.03V 5+The XRD pattern can be found Figure 1 The emission spectrum is shown below. Figure 3 .

[0056] Depend on Figure 1 It can be seen that the X-ray diffraction peaks of the luminescent material in this embodiment are consistent with those of the standard card, and no other impurities are observed.

[0057] Depend on Figure 3 It can be seen that the emission peak of the luminescent material in this embodiment is located near 480nm, and the luminescence intensity at the highest peak of the emission peak is about 320 counts.

[0058] Example 5

[0059] Preparation of vanadium ion-doped phosphate-based luminescent materials

[0060] The chemical formula of the vanadium ion-doped phosphate-based luminescent material prepared in this embodiment is: Ca9AlP 6.72 O 28 0.04V 5 + The preparation method is as follows:

[0061] According to the above chemical formula molar ratio, weigh out the raw materials CaCO3, Al2O3, NH4H2PO4, and V2O5 and place them in an agate mortar. Grind them into a uniformly mixed powder, then place the powder in an alumina crucible. First, maintain the temperature at 800℃ for 6 hours, grind it evenly, and then maintain the temperature at 1200℃ for 5 hours. The entire firing process is carried out in an air atmosphere. Afterward, cool the product to room temperature with the furnace. The product is then ground and pulverized to obtain Ca9AlP. 6.72 O 28 0.04V 5+ Luminescent materials.

[0062] The luminescent material in this embodiment is Ca9AlP. 6.72 O 28 0.04V 5+ The XRD pattern can be found Figure 1 The emission spectrum is shown below. Figure 3 .

[0063] Depend on Figure 1 It can be seen that the X-ray diffraction peaks of the luminescent material in this embodiment are consistent with those of the standard card, and no other impurities are observed.

[0064] Depend on Figure 3 It can be seen that the emission peak of the luminescent material in this embodiment is located near 480nm, and the luminescence intensity at the highest peak of the emission peak is about 514 counts.

[0065] Comparative Example 1

[0066] Preparation of vanadium ion-doped phosphate-based luminescent materials

[0067] The chemical formula of the vanadium ion-doped phosphate-based luminescent material prepared in this embodiment is: Ca9AlP 6.30 O 28 0.10V 5 + The preparation method is the same as in Example 3.

[0068] The luminescent material in this embodiment is Ca9AlP. 6.30 O 28 0.10V 5+ The XRD pattern can be found Figure 1 The emission spectrum is shown below. Figure 3 .

[0069] Depend on Figure 1 It can be seen that the X-ray diffraction peaks of the luminescent material in this embodiment are consistent with those of the standard card, and no other impurities are observed.

[0070] Depend on Figure 3 It can be seen that the emission peak of the luminescent material in this embodiment is located near 480nm, and the luminescence intensity at the highest peak of the emission peak is about 150 counts.

[0071] Structural and performance analysis of luminescent materials:

[0072] Figure 1 The X-ray diffraction patterns are shown for the luminescent materials prepared in Examples 1-5 and Comparative Example 1. Figure 1 It can be seen that vanadium-doped phosphate luminescent material Ca9AlP 7(1-x) O 28 :xV 5+ XRD patterns of (x = 0.005–0.04) and Ca9AlP7O 28 The standard card (PDF#00-048-1192) matches, indicating that the method used in the various embodiments of the present invention can obtain the component Ca9AlP7O. 28 The product of.

[0073] Figure 2 and Figure 3 The figures show the excitation and emission spectra of the luminescent materials prepared in Examples 1-5 and Comparative Example 1. As can be seen from the figures, the excitation peak of the sample is located near 300 nm, and the emission peak is located near 480 nm, indicating that the luminescent material can be excited by ultraviolet light to achieve photoluminescence, emitting cyan light. With V... 5+ As the ion doping concentration increases, the luminescence brightness of the luminescent material initially increases and then decreases. Furthermore, when V... 5+ The luminescence intensity is strongest when the ion doping concentration is x = 0.02. When V 5+ When the ion doping concentration is x = 0.10, the relative intensity of its emission spectrum is observed to be only V.5+ The 12% ion doping concentration at x = 0.02 is presumably due to severe concentration quenching caused by excessively high vanadium concentration.

[0074] Figure 4 The figures show the excitation and emission spectra of the luminescent material prepared in Example 3 at room temperature. As can be seen from the figures, the Ca9AlP luminescent material of Example 3... 6.86 O 28 0.02V 5+ The excitation peak of the luminescent material is located near 300 nm, and the emission peak is located near 480 nm. This luminescent material is Ca9AlP. 6.86 O 28 0.02V 5+ It can be excited by ultraviolet light and emit cyan light.

[0075] Figure 5 and Figure 6 The excitation and emission spectra of the luminescent material prepared in Example 3 are shown to change at different temperatures. As the temperature increases from room temperature (25°C) to 300°C, the luminescence intensity of the luminescent material decreases rapidly, indicating that temperature has a quenching effect on the luminescent material. This demonstrates the potential of this luminescent material for application in optical temperature sensors.

[0076] Figure 7 The graph shows the variation of the integrated emission intensity of the luminescent material prepared in Example 3 of this invention with temperature in the range of 25–300 °C, and the relationship between the graph and the fitted function. Points represent experimentally measured values, and curves represent the fitted function values. It can be seen that the integrated emission intensity of this luminescent material decreases with increasing temperature, and its integrated emission intensity (Ω) varies with temperature (T) according to the function Ω = 1.457*exp(-T / 145.367) - 0.169. Therefore, the vanadium ion-activated phosphate-based luminescent material provided by this invention can be used to measure temperature based on the change in the integrated emission intensity with temperature.

[0077] Figure 8 The luminescent material obtained in Example 3 of this invention is derived from the formula... (S R The temperature sensitivity curve obtained by plotting relative sensitivity (Ω: luminous integral intensity, T: temperature) shows that the core performance of this material is very high in temperature sensitivity, with a sensitivity of 2.03%℃ at 250℃. -1 This demonstrates that the material prepared by this invention exhibits good temperature sensitivity, maintaining a sensitivity of 1.91%℃ even at 300℃. -1 Furthermore, within the temperature range of 75–250℃, the material's temperature measurement sensitivity continuously increases with rising temperature, making it a luminescent thermometric material with great potential.

[0078] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A vanadium ion-doped phosphate-based luminescent material, characterized in that, Its general chemical formula is Ca9AlP 7(1-x) O 28 :xV 5+ , where x = 0.005 to 0.

04.

2. The application of the vanadium ion-doped phosphate-based luminescent material as described in claim 1 in the preparation of optical thermometers.

3. The application as described in claim 2, characterized in that, The optical thermometer references the integral intensity Ω of the emission spectrum of a vanadium ion-doped phosphate-based luminescent material under 300 nm ultraviolet light excitation as a function of temperature. T The function is Ω = 1.457 * exp(- T / 145.367)-0.169 change.

4. The method for preparing vanadium ion-doped phosphate-based luminescent material as described in claim 1, characterized in that, The material is made by firing a mixture of calcium-containing compounds, aluminum-containing compounds, phosphorus-containing compounds, and vanadium-containing compounds.

5. The method for preparing vanadium ion-doped phosphate-based luminescent material as described in claim 4, characterized in that, The calcium-containing compound is any one or a combination of two or more of the following: calcium oxides, carbonates, nitrates, hydroxides, and chlorides.

6. The method for preparing vanadium ion-doped phosphate-based luminescent material as described in claim 4, characterized in that, The aluminum-containing compound is any one or a combination of two or more of aluminum oxides, carbonates, nitrates, hydroxides, and chlorides.

7. The method for preparing vanadium ion-doped phosphate-based luminescent material as described in claim 4, characterized in that, The phosphorus-containing compound is any one or a combination of two or more of phosphorus oxides, phosphates, and hydrides.

8. The method for preparing vanadium ion-doped phosphate-based luminescent material as described in claim 4, characterized in that, The vanadium-containing compound is any one or a combination of two or more of vanadium oxides, halides, carbides, hydroxides, and chlorides.

9. The method for preparing vanadium ion-doped phosphate-based luminescent material as described in claim 4, characterized in that, The steps include: according to the general chemical formula Ca9AlP 7(1-x) O 28 :xV 5+ The raw materials containing calcium, aluminum, phosphorus and vanadium were weighed and mixed according to the molar ratio of Ca, Al, P and V. The mixture was then placed in a high-temperature air atmosphere for firing. After cooling in the furnace, the vanadium ion-doped phosphate-based luminescent material was obtained.

10. The method for preparing vanadium ion-doped phosphate-based luminescent material as described in claim 9, characterized in that, The firing process includes first holding the mixture at 700-800℃ for 4-6 hours, grinding it evenly, and then holding it at 1100-1200℃ for 3-5 hours.

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