A temperature sensing material based on dual-mode thermal response upconversion luminescence and a preparation method and application thereof

Abstract

The application discloses a temperature sensing material based on double-mode thermal response up-conversion luminescence and a preparation method and application thereof, and belongs to the technical field of optical temperature sensing. 4‑y Ti 0.5 M 0.5 O8X:REy; wherein, M is W or Mo, X is Cl or Br, RE is Er or Yb / Er, and a hydrothermal-molten salt method is adopted to prepare the material by using a string joint strategy. Different from traditional thermal quenching materials, the double-mode thermal response up-conversion luminescence temperature sensing material Bi4Ti 0.5 M 0.5 O8X can weaken visible light and enhance 800nm near-infrared light at the same time as temperature rises. By utilizing the characteristics that the up-conversion luminescence intensity has opposite responses to temperature changes, the up-conversion temperature sensing material has high optical temperature sensitivity in a fluorescence intensity mode and a fluorescence lifetime mode, is a wide temperature measurement range optical temperature sensing material that can be used for high-temperature environment detection, and has great application potential in the field of optical temperature sensing.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of optical temperature sensing, and particularly relates to a temperature sensing material based on a double-mode thermal response upconversion luminescence and a preparation method and application thereof. BACKGROUND

[0002] Rare earth upconversion luminescence materials have the advantages of strong visible light emission, long service life, fast response, non-contact, strong anti-interference ability, high temperature measurement resolution, and the like, and have a broad application prospect in optical temperature measurement. The temperature sensing of the fluorescence intensity ratio (FIR) technology is a detection technology for reflecting the surrounding environment by using the relationship between the intensity ratio of two luminescence peaks and temperature, and is the most widely used optical temperature measurement technology at present. With the development of fluorescence temperature sensing technology, people have put forward higher and higher requirements for the performance of upconversion luminescence materials, especially the upconversion luminescence efficiency. In addition to the luminescence efficiency, the luminescence thermal stability of the material is also an important indicator for measuring whether the material can realize practical application. However, the luminescence efficiency of most rare earth upconversion luminescence materials will decrease significantly with the increase of temperature, that is, fluorescence thermal quenching occurs, which seriously hinders the application of the materials in optical temperature sensing.

[0003] Generally speaking, high temperature leads to fluorescence quenching of luminescence materials mainly because the increase of temperature intensifies the vibration of the substrate crystal lattice, thereby increasing the electron-phonon interaction and the non-radiative transition rate, and thus reducing the luminescence intensity and lifetime.

[0004] The Sillen-Aurivillius perovskite structure layered Bi4M 0.5 Ti 0.5 O8X (M = W, Mo; X = Cl, Br), the [Bi2O2] 2+ layer and the interleaved negatively charged ion / polyhedron layer are connected by van der Waals force and form an internal electric field. In the two-dimensional layered crystal formed by the van der Waals force connection, phonons have a higher migration ability along the two-dimensional structure direction of the material, and electrons mainly transmit and migrate along the three-dimensional direction. The existing internal electric field will induce directional migration of the electrons, thereby reducing the coupling degree of phonon-electron at high temperature, realizing a certain degree of phonon-electron decoupling, and effectively inhibiting phonon scattering. Therefore, when the above factors act together, the electron-phonon coupling effect is regulated by the internal electric field, and then the phonon scattering effect is reduced and the non-radiative relaxation process at high temperature is inhibited, which will make it possible to realize the abnormal thermal enhancement luminescence of rare earth ions. The energy level of Er 3+ ions is rich, and the emission spectrum covers a wide range from deep ultraviolet to near infrared wavelength, which is particularly attractive. So far, most of the researches on upconversion luminescence materials are based on Er 3+The related researches are focused on the emission bands of blue light, green light and red light, and the 800nm near-infrared emission cannot be detected due to the weak emission band, 4 I 9 / 2 - 4 I 15 / 2 The transition seems to be ignored for a long time, and the research on the thermal enhanced luminescence thereof is even less, and it is of great significance to introduce Er into the perovskite layered material to study the 800nm near-infrared thermal enhanced luminescence thereof. SUMMARY

[0005] To solve the problems of serious thermal quenching and low luminescent efficiency of the existing upconversion material, one of the purposes of the present application is to provide a dual-mode thermal response upconversion luminescence temperature sensing material, and the chemical formula of the material is: Bi 4-y Ti 0.5 M 0.5 O8X:RE y , wherein y=0.01-0.2, M is W or Mo, X is Cl or Br, and RE is Er or Yb / Er.

[0006] The Er ion is single-doped or Yb / Er is co-doped in Bi4M 0.5 Ti 0.5 O8X, and an upconversion material with dual-mode thermal response and near-infrared luminescence thermal enhancement is obtained, and the optimal absolute sensitivity and relative sensitivity are 72.26%K -1 and 8.27%K -1 , respectively, at 293K-493K.

[0007] Another purpose of the present application is to provide a preparation method of the rare dual-mode thermal response upconversion luminescence temperature sensing material, and the method comprises the following steps:

[0008] (1) the bismuth source is dissolved in a mannitol solvent, and after stirring and uniform mixing, an aqueous solution of halide is added, and the obtained mixed solution is subjected to hydrothermal reaction, centrifugation, washing and drying to obtain a BiOX precursor, wherein X is Cl or Br;

[0009] (2) the BiOX, Bi2O3, MO3, TiO2 and rare earth ions are uniformly mixed, NaCl and KCl are added, and the mixture is fully ground and stirred to obtain a mixture, the mixture is subjected to sintering treatment, washing and drying, and the Bi 4-y Ti 0.5 M 0.5 O8X:RE y fluorescent powder is obtained, wherein y=0.01-0.2, M is W or Mo, X is Cl or Br, and RE is Er or Yb / Er.

[0010] Preferably, the molar volume ratio of the bismuth source to the mannitol solution in step (1) is (0.05-0.1):30, unit: mol:mL; the bismuth source is one of Bi(NO3)3.5H2O, CBi2O5, Bi2(SO4)3, Bi2O3, BiPO4, and the molar concentration of the mannitol solvent is 0.1 mol / mL.

[0011] Preferably, the volume ratio of the aqueous halide solution to the mannitol solvent in step (1) is (2-3):30, the molar concentration of the aqueous halide solution is 2.5 mol / mL, and the halide is a halide containing Cl or Br.

[0012] Preferably, the hydrothermal reaction temperature in step (1) is 120-220 DEG C, and the hydrothermal reaction time is 6-36 h.

[0013] Preferably, the rare earth ion source in step (2) is one or more of RECl3 and RE2O3; and the rare earth ion is Er or Yb / Er.

[0014] Preferably, the amount-of-substance ratio of Bi2O3, BiOX, MO3, TiO2, and the rare earth ion in step (2) is (2.80-2.99):2:1:1:(0.01-0.3), wherein MO3 is WO3 or MoO3.

[0015] Preferably, the amount of NaCl and KCl added in step (2) is 1-20 times the total mass of BiOX, Bi2O3, MO3, TiO2, and the rare earth ion, and the amount-of-substance ratio of NaCl and KCl is 1:1.

[0016] Preferably, the sintering temperature in step (2) is 400-800 DEG C, and the sintering time in air atmosphere is 1-24 h.

[0017] The prepared bimodal thermally responsive upconversion luminescence temperature sensing material can be applied in optical temperature sensing.

[0018] Advantages of the present application

[0019] (1) The bimodal thermally responsive upconversion luminescence temperature sensing material of the present application has good luminescence properties, stable physical and chemical properties, simple preparation method, mild reaction conditions, and low raw material cost. 4-y Ti 0.5 M 0.5 O8X:RE y The material is expected to be applied as a high-sensitivity optical anti-counterfeiting material, an ultraviolet detector, a temperature sensor, a photovoltaic ferroelectric material, and a photo-mechanical material sensing material.

[0020] (2) The prepared dual-mode thermal response upconversion luminescence temperature sensing material of the application shows strong luminescence intensity, and the luminescence intensity of Er 3+ The ions exhibit opposite thermal response phenomena in the visible light and near-infrared light emission band, and realize thermal enhancement of 800 nm near-infrared light emission. The opposite response characteristics can effectively improve the optical temperature sensing sensitivity, and have great significance for designing and developing accurate and efficient optical thermometers.

[0021] (3) The prepared Bi 4-y Ti 0.5 M 0.5 O8X:RE y The prepared dual-mode thermal response upconversion luminescence temperature sensing material has high optical temperature sensitivity in fluorescence intensity mode and fluorescence lifetime mode, and is a wide temperature measurement range optical temperature sensing material that can be used for high temperature environment detection, and has great application potential in the field of optical temperature sensing. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 The X-ray diffraction pattern of the dual-mode thermal response upconversion luminescence temperature sensing material prepared in Examples 1-5 is compared with the standard card.

[0023] Figure 2 The upconversion emission spectrum of the dual-mode thermal response upconversion luminescence temperature sensing material prepared in Examples 1-5 under 980 nm excitation is compared.

[0024] Figure 3 The upconversion variable temperature emission spectrum of the dual-mode thermal response upconversion luminescence temperature sensing material prepared in Example 3 under 980 nm excitation is shown.

[0025] Figure 4 The upconversion variable temperature emission spectrum of the dual-mode thermal response upconversion luminescence temperature sensing material prepared in Example 3 under 980 nm excitation is shown. Figure 3 The near-infrared and green non-thermal coupling temperature sensitive factor fitting of the upconversion variable temperature emission spectrum under 980 nm excitation. DETAILED DESCRIPTION

[0026] The technical solutions of the application will be further described below in combination with the drawings and through specific embodiments. However, the following examples are only simple examples of the application, and do not represent or limit the protection scope of the application, and the protection scope of the application is subject to the claims.

[0027] Example 1

[0028] The chemical formula of the dual-mode thermal response upconversion luminescence temperature sensing material of this embodiment is Bi 3.99 Ti 0.5 W 0.5 O8Cl:Er 0.01 , and the preparation method is as follows:

[0029] (1) 0.05 mol of Bi(NO3)3·5H2O was added to 30 mL of an aqueous solution of mannitol with a molar concentration of 0.1 mol / mL, after stirring until the solution was transparent, 2 mL of a KCl solution with a concentration of 2.5 mol / mL was added, and after sufficient stirring, a mixed solution was obtained, the mixed solution was transferred to a polytetrafluoroethylene reaction kettle, and a hydrothermal reaction was carried out at 120°C for 6 hours, after the reaction was completed, it was naturally cooled to room temperature, a precipitate was obtained, and after washing with ionized water and ethanol by centrifugation, drying was carried out at 70°C, thereby obtaining a BiOCl precursor.

[0030] (2) Bi2O3, BiOCl, WO3, TiO2, and Er2O3 were mixed in a molar mass ratio of 2.99:2:1:1:0.01, and NaCl and KCl were added in an amount of 1 times the total mass of Bi2O3, BiOCl, WO3, TiO2, and Er2O3, after sufficient grinding, they were transferred to a crucible, sintered at 600°C for 6 hours, naturally cooled to room temperature, washed with warm water, and dried at 70°C, thereby obtaining a Bi 3.99 Ti 0.5 W 0.5 O8Cl:Er 0.01 .

[0031] Example 2

[0032] The chemical formula of the dual-mode thermal response upconversion luminescence temperature sensing material of this example is Bi 3.95 Ti 0.5 W 0.5 O8Cl:Er 0.05 , and the preparation method is as follows:

[0033] (1) 0.1 mol of CBi2O5 was added to 30 mL of an aqueous solution of mannitol with a molar concentration of 0.1 mol / mL, after stirring until the solution was transparent, 3 mL of a KCl solution with a concentration of 2.5 mol / mL was added, and after sufficient stirring, a mixed solution was obtained, the mixed solution was transferred to a polytetrafluoroethylene reaction kettle, and a hydrothermal reaction was carried out at 160°C for 12 hours, after the reaction was completed, it was naturally cooled to room temperature, a precipitate was obtained, and after washing with ionized water and ethanol by centrifugation, drying was carried out at 70°C, thereby obtaining a BiOCl precursor.

[0034] (2) Bi2O3, BiOCl, WO3, TiO2, and Er2O3 were mixed in a molar mass ratio of 2.95:2:1:1:0.05, and NaCl and KCl were added in an amount of 3 times the total mass, after sufficient grinding, they were transferred to a crucible, sintered at 660°C for 8 hours, naturally cooled to room temperature, washed with warm water, and dried at 70°C, thereby obtaining a Bi 3.95 Ti 0.5 W 0.5 O8Cl:Er0.05

[0035] Example 3

[0036] The chemical formula of the dual-mode thermally responsive upconversion luminescence temperature sensing material of this example is Bi 3.90 Ti 0.5 W 0.5 O8Cl:Er 0.1 , and the preparation method is as follows:

[0037] (1) 0.05 mol of BiPO4 was added to 30 mL of a mannitol aqueous solution with a molar concentration of 0.1 mol / mL, after stirring until the solution was transparent, 2 mL of a NaCl solution with a concentration of 2.5 mol / mL was added, and after sufficient stirring, a mixed solution was obtained, the mixed solution was transferred to a polytetrafluoroethylene reaction kettle, and a hydrothermal reaction was carried out at 180°C for 14 hours, after the reaction was completed, natural cooling was carried out to room temperature, a precipitate was obtained, the precipitate was washed by centrifugation using ionized water and ethanol respectively, and drying was carried out at 70°C, thereby obtaining a BiOCl precursor.

[0038] (2) Bi2O3, BiOCl, WO3, TiO2, and Er2O3 were mixed in a molar mass ratio of 2.90:2:1:1:0.1, the addition amount of NaCl and KCl was 5 times the total mass, after sufficient grinding, it was transferred to a crucible, sintering was carried out at 700°C for 10 hours, natural cooling was carried out to room temperature, after washing with warm water, drying was carried out at 70°C, thereby obtaining Bi 3.9 Ti 0.5 W 0.5 O8Cl:Er 0.1 .

[0039] Example 4

[0040] The chemical formula of the dual-mode thermally responsive upconversion luminescence temperature sensing material of this example is Bi 3.85 Ti 0.5 W 0.5 O8Cl:Er 0.15 , and the preparation method is as follows:

[0041] (1) 0.05 mol of Bi(NO3)3·5H2O was added to 30 mL of a mannitol aqueous solution with a molar concentration of 0.1 mol / mL, after stirring until the solution was transparent, 2 mL of a KCl solution with a concentration of 2.5 mol / mL was added, and after sufficient stirring, a mixed solution was obtained, the mixed solution was transferred to a polytetrafluoroethylene reaction kettle, and a hydrothermal reaction was carried out at 200°C for 18 hours, after the reaction was completed, natural cooling was carried out to room temperature, a precipitate was obtained, the precipitate was washed by centrifugation using ionized water and ethanol respectively, and drying was carried out at 70°C, thereby obtaining a BiOCl precursor.

[0042] (2) Bi2O3, BiOCl, WO3, TiO2, ErCl3 are mixed in a molar ratio of 2.85:2:1:1:0.3, NaCl and KCl are added in an amount of 7 times the total mass, and after being ground thoroughly, they are transferred into a crucible, sintered at 750°C for 12 hours, naturally cooled to room temperature, washed with warm water, and dried at 70°C to obtain Bi 3.85 Ti 0.5 W 0.5 O8Cl:Er 0.15 .

[0043] Example 5

[0044] The chemical formula of the bimodal thermally responsive upconversion luminescence temperature sensing material of this example is Bi 3.8 Ti 0.5 W 0.5 O8Cl:Er 0.2 , and the preparation method is as follows:

[0045] (1) 0.05 mol of Bi(NO3)3·5H2O is added to a 30 mL aqueous solution of mannitol with a molar concentration of 0.1 mol / mL, and after stirring until the solution is transparent, 2 mL of a KCl solution with a concentration of 2.5 mol / mL is added, and after being stirred thoroughly, a mixed solution is obtained, which is transferred into a polytetrafluoroethylene reaction kettle, and a hydrothermal reaction is performed at 220°C for 24 hours, and after the reaction is completed, it is naturally cooled to room temperature, and a precipitate is obtained, which is washed by centrifugation with ionized water and ethanol, and dried at 70°C to obtain a BiOCl precursor.

[0046] (2) Bi2O3, BiOCl, WO3, TiO2, Er2O3 are mixed in a molar ratio of 2.80:2:1:1:0.2, NaCl and KCl are added in an amount of 10 times the total mass, and after being ground thoroughly, they are transferred into a crucible, sintered at 800°C for 24 hours, naturally cooled to room temperature, washed with warm water, and dried at 70°C to obtain Bi 3.8 Ti 0.5 W 0.5 O8Cl:Er 0.2 .

[0047] Example 6

[0048] The chemical formula of the bimodal thermally responsive upconversion luminescence temperature sensing material of this example is Bi 3.8 Ti 0.5 W 0.5 O8Cl:Er 0.1 Yb 0.1 , and the preparation method is as follows:

[0049] (1) 0.05 mol of Bi (NO3) 3 ·5H2O was added to 30 mL of a mannitol aqueous solution with a molar concentration of 0.1 mol / mL, after stirring until the solution was transparent, 2 mL of a KCl solution with a concentration of 2.5 mol / mL was added, after sufficient stirring, a mixed solution was obtained, the mixed solution was transferred to a polytetrafluoroethylene reaction kettle, a hydrothermal reaction was carried out at 160°C for 6 hours, after the reaction was completed, natural cooling was carried out to room temperature, a precipitate was obtained, the precipitate was washed by centrifugation using deionized water and ethanol respectively, and drying was carried out at 70°C, thereby obtaining a BiOCl precursor.

[0050] (2) Bi2O3, BiOCl, WO3, TiO2, Er2O3, Yb2O3 were mixed according to a molar mass ratio of 2.8:2:1:1:0.1:0.1, the addition amount of NaCl and KCl was 5 times the total mass, after sufficient grinding, it was transferred to a crucible, sintering was carried out at 660°C for 18 hours, natural cooling was carried out to room temperature, after washing with warm water, drying was carried out at 70°C, thereby obtaining a Bi 3.8 Ti 0.5 W 0.5 O8Cl:Er 0.1 , Yb 0.1 .

[0051] The sample prepared in this example has similar optical properties to the sample of Example 3, and also has a 800 nm thermal enhancement phenomenon.

[0052] Example 7

[0053] The chemical formula of the bimodal thermal response upconversion luminescence temperature sensing material of this example is Bi 3.8 Ti 0.5 W 0.5 O8Br:Er 0.1 Yb 0.1 , and the preparation method is as follows:

[0054] (1) 0.05 mol of Bi (NO3) 3 ·5H2O was added to 30 mL of a mannitol aqueous solution with a molar concentration of 0.1 mol / mL, after stirring until the solution was transparent, 2 mL of a KBr solution with a concentration of 2.5 mol / mL was added, after sufficient stirring, a mixed solution was obtained, the mixed solution was transferred to a polytetrafluoroethylene reaction kettle, a hydrothermal reaction was carried out at 160°C for 6 hours, after the reaction was completed, natural cooling was carried out to room temperature, a precipitate was obtained, the precipitate was washed by centrifugation using deionized water and ethanol respectively, and drying was carried out at 70°C, thereby obtaining a BiOBr precursor.

[0055] (2) Bi2O3, BiOCl, WO3, TiO2, Er2O3, Yb2O3 are mixed according to the molar mass 2.8:2:1:1:0.1:0.1, the addition amount of NaCl, KCl is 5 times of the total mass, after grinding, it is transferred into a crucible, sintered at 660℃ for 20 hours, naturally cooled to room temperature, washed with warm water, dried at 70℃ to obtain Bi 3.8 Ti 0.5 W 0.5 O8Cl:Er 0.1， Yb 0.1 .

[0056] Example 8

[0057] The chemical formula of the bimodal thermal response upconversion luminescence temperature sensing material of the embodiment is Bi 3.99 Ti 0.5 W 0.5 O8Br:Er 0.01 , and the preparation method is as follows:

[0058] (1) 0.05 mol of Bi2O3 is added into 30 mL of a mannitol aqueous solution with a molar concentration of 0.1 mol / mL, after stirring until the solution is transparent, 2 mL of a KBr solution with a concentration of 2.5 mol / mL is added, after sufficient stirring, a mixed solution is obtained, the mixed solution is transferred into a polytetrafluoroethylene reaction kettle, and a hydrothermal reaction is carried out at 160℃ for 36 hours, after the reaction is completed, it is naturally cooled to room temperature, a precipitate is obtained, the precipitate is washed by centrifugation with ionized water and ethanol respectively, and dried at 70℃ to obtain a BiOBr precursor.

[0059] (2) Bi2O3, BiOBr, WO3, TiO2, Er2O3 are mixed according to the molar mass 2.99:2:1:1:0.01, the addition amount of NaCl, KCl is 12 times of the total mass, after grinding, it is transferred into a crucible, sintered at 680℃ for 12 hours, naturally cooled to room temperature, washed with warm water, and dried at 70℃ to obtain Bi 3.99 Ti 0.5 W 0.5 O8Br:Er 0.01 .

[0060] Example 9

[0061] The chemical formula of the bimodal thermal response upconversion luminescence temperature sensing material of the embodiment is Bi 3.99 Ti 0.5 W 0.5 O8Br:Er 0.01 , and the preparation method is as follows:

[0062] (1) 0.05 mol of Bi2O3 was added to 30 mL of a mannitol aqueous solution with a molar concentration of 0.1 mol / mL, after stirring until the solution was transparent, 2 mL of a NH4Cl solution with a concentration of 2.5 mol / mL was added, after sufficient stirring, a mixed solution was obtained, the mixed solution was transferred to a polytetrafluoroethylene reaction kettle, and a hydrothermal reaction was performed at 160°C for 12 hours, after the reaction was completed, natural cooling was performed to room temperature, a precipitate was obtained, the precipitate was washed by centrifugation using ion water and ethanol respectively, and drying was performed at 70°C, thereby obtaining a BiOBr precursor.

[0063] (2) Bi2O3, BiOBr, WO3, TiO2, Er2O3 were mixed in a molar mass ratio of 2.95:2:1:1:0.5, the addition amount of NaCl and KCl was 16 times the total mass, after sufficient grinding, it was transferred to a crucible, sintering was performed at 680°C for 12 hours, natural cooling was performed to room temperature, after washing with warm water, drying was performed at 70°C, thereby obtaining Bi 3.95 Ti 0.5 W 0.5 O8Br:Er 0.05 .

[0064] Example 10

[0065] The chemical formula of the dual-mode thermal response upconversion luminescence temperature sensing material of this example is Bi 3.99 Ti 0.5 Mo 0.5 O8Cl:Er 0.01 , and the preparation method is as follows:

[0066] (1) 0.05 mol of Bi2(SO4)3 was added to 30 mL of a mannitol aqueous solution with a molar concentration of 0.1 mol / mL, after stirring until the solution was transparent, 2 mL of a NH4Cl solution with a concentration of 2.5 mol / mL was added, after sufficient stirring, a mixed solution was obtained, the mixed solution was transferred to a polytetrafluoroethylene reaction kettle, and a hydrothermal reaction was performed at 180°C for 12 hours, after the reaction was completed, natural cooling was performed to room temperature, a precipitate was obtained, the precipitate was washed by centrifugation using ion water and ethanol respectively, and drying was performed at 70°C, thereby obtaining a BiOCl precursor.

[0067] (2) Bi2O3, BiOBr, MoO3, TiO2, Er2O were mixed in a molar mass ratio of 2.99:2:1:1:0.01, the addition amount of NaCl and KCl was 18 times the total mass, after sufficient grinding, it was transferred to a crucible, sintering was performed at 680°C for 12 hours, natural cooling was performed to room temperature, after washing with warm water, drying was performed at 70°C, thereby obtaining Bi 3.99 Ti 0.5 Mo 0.5 O8Cl:Er 0.01 .

[0068] Example 11

[0069] The chemical formula of the dual-mode thermal response upconversion luminescence temperature sensing material of this example is Bi 3.99 Ti 0.5 Mo 0.5 O8Br:Er 0.01 , and the preparation method is as follows:

[0070] (1) 0.05 mol of Bi(NO3)3·5H2O was added to 30 mL of a mannitol aqueous solution with a molar concentration of 0.1 mol / mL, after stirring until the solution was transparent, 2 mL of a KCl solution with a concentration of 2.5 mol / mL was added, and after sufficient stirring, a mixed solution was obtained. The mixed solution was transferred to a polytetrafluoroethylene reaction kettle, and a hydrothermal reaction was carried out at 160°C for 24 hours. After the reaction was completed, natural cooling was carried out to room temperature, a precipitate was obtained, and the precipitate was washed by centrifugation with ionized water and ethanol respectively, and then dried at 70°C to obtain a BiOCl precursor.

[0071] (2) Bi2O3, BiOBr, MoO3, TiO2, and Er2O3 were mixed according to a molar mass ratio of 2.99:2:1:1:0.01, and the addition amount of NaCl and KCl was 20 times the total mass. After being ground sufficiently, they were transferred to a crucible and sintered at 700°C for 6 hours. After natural cooling to room temperature, they were washed with warm water and dried at 70°C to obtain Bi 3.99 Ti 0.5 Mo 0.5 O8Br:Er 0.01 .

[0072] Comparative Example 1

[0073] A material with a chemical formula of NaYF4:20%Yb 3+ , 2%Er 3+ was prepared in this example, and the preparation method is as follows:

[0074] (1) A RE(NO3)3 standard solution (Y / Yb / Er 1 / 478:20:2, a total of 2 mmol) was added dropwise to an 8 mL aqueous solution containing 2 mmol of EDTA-2Na to obtain a chelated RE-EDTA complex. After stirring for 30 minutes, 28 mL of an aqueous solution containing 25 mmol of NaF was added to the above solution and stirred for 1 hour to obtain a mixed solution. The mixed solution was transferred to a polytetrafluoroethylene reaction kettle, and a hydrothermal reaction was carried out at 180°C for 24 hours. After the reaction was completed, natural cooling was carried out to room temperature, a precipitate was obtained, and the precipitate was washed by centrifugation with deionized water and ethanol respectively, and then dried at 70°C to obtain NaYF4:20%Yb 3+ , 2%Er 3+ .

[0075] The material prepared in this comparative example has no 800 nm thermal enhancement phenomenon compared with the material prepared in Example 3.

[0076] Comparative Example 2

[0077] A material with the chemical formula Bi 11.9 O 17 Br2:Er 0.1 was prepared in this example, and the preparation method and the amount of each substance were the same as in Example 3, as follows:

[0078] (1) 0.05 mol of Bi (NO3) 3· 5H2O was added to 30 mL of a mannitol aqueous solution with a molar concentration of 0.1 mol / mL, and after stirring until the solution was transparent, 2 mL of a KBr solution with a concentration of 2.5 mol / mL was added. After sufficient stirring, a mixed solution was obtained. The mixed solution was transferred to a polytetrafluoroethylene reaction kettle, and a hydrothermal reaction was carried out at 160°C for 24 hours. After the reaction was completed, natural cooling to room temperature was carried out, and a precipitate was obtained. After washing the precipitate with deionized water and ethanol by centrifugation, drying was carried out at 70°C, and BiOBr precursor was obtained.

[0079] (3) Bi2O3, BiOBr, and Er2O3 were mixed in a molar mass ratio of 5:2:0.1, and the addition amount of NaCl and KCl was 5 times the total mass. After sufficient grinding, it was transferred to a crucible and sintered at 720°C for 8 hours. After natural cooling to room temperature, washing with warm water was carried out, and drying was carried out at 70°C to obtain Bi 11.9 O 17 Br2:Er 0.1 .

[0080] The material prepared in this comparative example has no strong upconversion luminescence intensity and 800 nm near-infrared thermal enhancement phenomenon compared with the material prepared in Example 3.

[0081] Performance Test

[0082] The materials prepared in Examples 1 to 5 were subjected to relevant performance tests. First, the prepared materials were subjected to X-ray diffraction analysis, and the results are shown in Figure 1 From the figure, it can be seen that the samples with different Er doping concentrations synthesized are pure phases, and changing the conditions and doping concentrations does not affect the phase purity.

[0083] The prepared materials were subjected to upconversion emission spectrum analysis under 980 nm excitation light, and the results are shown in Figure 2 From the figure, it can be seen that with the increase of the doping concentration, the luminescence intensity first increases and then decreases, and the luminescence is the strongest in Example 3 with a doping concentration of 10%.

[0084] The material prepared in Example 3 was subjected to upconversion variable-temperature emission spectrum analysis under 980 nm excitation, and the results are shown in Figure 3 From the figure, it can be seen that as the temperature rises from 293 K to 493 K, the green light emission at 524 nm and 542 nm and the red light emission at 670 nm present completely opposite changes in intensity to the near-infrared emission at 800 nm, and the green light and red light emission intensity continuously weakens as the temperature rises, while the 800 nm near-infrared emission continuously strengthens as the temperature rises.

[0085] The material prepared in Example 3 was subjected to upconversion variable-temperature emission spectrum near-infrared and green light non-thermal coupling temperature sensitivity factor fitting under 980 nm excitation, and the results are shown in Figure 4 From the figure, it can be seen that the relative sensitivity (Sr) is a maximum of 8.27% K -1 at 298 K, and the absolute sensitivity (Sa) is a maximum of 72.26% K -1 at 493 K.

Claims

1. A temperature sensing material based on dual-mode thermal response upconversion luminescence, characterized in that: Chemical formula: Bi 4- y Ti 0.5 W 0.5 O8Cl:Er y wherein y = 0.01-0.

2.

2. The method for preparing the temperature sensing material based on the dual-mode thermal response upconversion luminescence according to claim 1, characterized in that: The method comprises the following steps: (1) dissolving a bismuth source in a mannitol solvent, stirring and mixing, then adding an aqueous solution of a halide containing Cl, and performing a hydrothermal reaction on the obtained mixed solution, and then centrifuging, washing, and drying to obtain a BiOCl precursor; (2) BiOCl, Bi2O3, WO3, TiO2, Er ion source are mixed uniformly, then NaCl and KCl are added and fully ground and stirred to obtain a mixture, the mixture is sintered, washed, and dried to obtain Bi 4-y Ti 0.5 W 0.5 O8Cl:Er y fluorescent powder, wherein y = 0.01 ~ 0.

2. 3.The method of claim 2, wherein the temperature sensing material based on dual-mode thermal response upconversion luminescence is prepared by the following steps. In step (1), the molar volume ratio of the bismuth source to the mannitol solution is (0.05-0.1):30, unit mol:mL; the bismuth source is Bi(NO3)3·5H2O, and the molar concentration of the mannitol solvent is 0.1 mol / mL. 4.The method of claim 2, wherein the method further comprises: In step (1), the volume ratio of the aqueous solution of the halide containing Cl to the mannitol solvent is (2-3):30, and the molar concentration of the aqueous solution of the halide containing Cl is 2.5 mol / mL. 5.The method of claim 2, wherein the temperature sensing material based on dual-mode thermal response upconversion luminescence is prepared by the following steps. In step (1), the hydrothermal reaction temperature is 120-220°C, and the hydrothermal reaction time is 6-36 h. 6.The method of claim 2, wherein the temperature sensing material based on dual-mode thermal response upconversion luminescence is prepared by the following steps. In step (2), the Er ion source is one or more of ErCl3 and Er2O3. 7.The method of claim 2, wherein the temperature sensing material based on dual-mode thermal response upconversion luminescence is prepared by the following steps. In step (2), the amount-of-substance ratio of Bi2O3, BiOCl, WO3, TiO2, and the Er ion source is (2.80-2.99):2:1:1:(0.01-0.3). 8.The method of claim 2, wherein the temperature sensing material based on dual-mode thermal response upconversion luminescence is prepared by the following steps. In step (2), the amount of NaCl and KCl added is 1-20 times the total mass of BiOCl, Bi2O3, WO3, TiO2, and the Er ion source, and the amount-of-substance ratio of NaCl to KCl is 1:

1.

9. The method for preparing a temperature sensing material based on dual-mode thermal response upconversion luminescence according to claim 2, characterized in that: In step (2), the sintering temperature is 400-800°C, and the sintering time in an air atmosphere is 1-24 h.

10. Application of the temperature sensing material based on the dual-mode thermal response upconversion luminescence of claim 1 in optical temperature sensing.

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