A luminescent nanocrystal material, and a preparation method and application thereof

Abstract

The application provides a luminescent nanocrystal material and a preparation method and application thereof. The luminescent nanocrystal material has a general formula of Zr 1‑x‑y Ti x Eu y O 2‑0.5y The nanocrystal of the application has a small size and good dispersibility in water and ethanol. In the luminescent nanocrystal material, Eu 3+ occupies two different symmetrical lattice sites, Eu(I)(CN8) and Eu(II)(CN7); the doped Ti 4+ is not randomly distributed with Eu 3+ ions, and the Ti 4+ is preferentially associated with Eu(II), and can occur from O 2‑ →Ti 4+ charge transfer excitation to Eu 3+ effective energy transfer, which widens the effective excitation wavelength range of Eu 3+ and improves the luminescent efficiency. O 2‑ →Ti 4+ charge transfer transition is an electric dipole allowed transition, has a large absorption cross section, can produce white light broadband emission at low temperature, has high temperature sensitivity, and can be applied in non-contact temperature sensing and other fields.

Description

Technical Field

[0001] This invention relates to the field of luminescent materials technology, and in particular to a luminescent nanocrystalline material, its preparation method, and its application. Background Technology

[0002] Luminescent nanocrystals have potential applications in optoelectronic devices, fluorescence sensing, information encoding, and biomedicine, attracting significant attention from researchers. This is mainly due to their small size, rich surface modification chemistry, and excellent multicolor photoluminescence properties. Inorganic luminescent nanocrystals typically consist of activators (lanthanides and transition metal ions) and nanoscale matrix materials (such as simple oxides, fluorides, vanadates, phosphates, and borates). Generally, the activator is present in small quantities, doped into the matrix lattice as impurities, occupying lattice sites with a certain symmetry. Luminescence can be achieved through direct excitation of the activator or through indirect excitation via the matrix lattice followed by energy transfer to the activator. The choice of matrix is ​​crucial for obtaining high-performance luminescent materials. The spectral characteristics of ions are closely related to the matrix lattice, its local symmetry environment, and the distribution of the ions themselves. High-performance luminescence often requires a matrix with a wide band gap to accommodate the ground and excited states of the activator, aiming to reduce non-radiative transitions such as photo / thermal ionization of the luminescent energy levels. Zirconia (ZrO2) is a simple transition metal oxide with a moderate band gap of approximately 5-6.0 eV, attracting significant interest in the doping design, luminescence properties, and applications of novel phosphors. Furthermore, zirconium dioxide possesses low phonon energy, excellent chemical and mechanical stability, high refractive index and dielectric constant, biocompatibility, and is non-toxic and non-polluting. These characteristics make zirconium dioxide a promising photonic material for cation doping, semiconductor substrates, and optical anti-reflection coatings. As a matrix material for ion doping, low phonon energy helps reduce the non-radiative relaxation rate and improve luminescence efficiency. Currently, various activator ions have been intentionally doped into zirconium oxide nanocrystals, including lanthanides (Ln...). 3+ ) series (Pr 3+ 、Nd 3+ 、Sm 3+ Eu 3+ 、Tb 3+ Dy 3+ Er 3+ Tm 3+ Yb 3+ ) and some transition metal (TM) ions (Ti 4+ Ni 2+ Mn 2+Multicolor luminescence, ranging from visible to infrared, was observed. These multicolor luminescent zirconia nanocrystals can be used as fluorescent markers for bioimaging, as well as for fluorescent information encoding, fluorescent inks, fluorescent sensors, biosensors, electronic printing, and luminescent anti-counterfeiting.

[0003] Highly efficient luminescence has always been the unwavering goal of luminescent materials. In addition, based on the aforementioned applications, high-performance zirconia luminescent nanocrystals should also possess characteristics such as small size and narrow distribution, good colloidal stability, and strong spectral tunability (e.g., generating different colors of emission with different excitation wavelengths or generating different colors of emission with a single wavelength). Specifically, bioimaging, fluorescent inks, and electronic printing require nanocrystals to be small in size, narrow in distribution, and have good colloidal stability in solution; information encoding requires significant differences in emission color / wavelength, intensity, or fluorescence lifetime among the luminescent centers within the nanocrystals. Generally, spectral modulation is achieved by changing the concentration or type of activator ions, i.e., using multiple nanocrystals with different doping modes to achieve multi-channel fluorescence imaging or information encoding. This introduces complexity and inhomogeneity into the application system. If the distribution or lattice symmetry of dopant ions can be controlled within a single nanocrystal to achieve significant and identifiable differences in excitation and emission spectra, fluorescence lifetime, etc., it can broaden / increase the independent channels for fluorescence imaging / information encoding, improve encoding efficiency, reduce the types of nanocrystal applications, lower production costs, and enhance the multifunctionality and flexibility of luminescent nanocrystal applications, thus possessing significant application value. Performing multi-site doping on a single nanocrystal while maintaining strong luminescence is extremely challenging and places high demands on the design and fabrication methods of nanocrystals.

[0004] ZrO2 has multiple crystal forms. It is stable as a monoclinic phase at room temperature, transforms into a tetragonal phase at moderate temperatures, and then into a cubic phase at high temperatures. The high-temperature metastable phase can be produced by doping with heterovalent ions (such as rare earth ions, Sc). 3+ Ca 2+ or Mg 2+ (etc.) or reducing the particle size to the nanoscale to achieve stable existence at room temperature. Regular tetragonal ZrO2 possesses a D... 2dLattice sites, with their low symmetry, are suitable for doping trivalent rare-earth ion activators to achieve efficient luminescence. Trivalent (3+) rare-earth ion activators are heterovalent dopants, unlike the matrix lattice site charge (4+), and often require anionic oxygen vacancies for compensation. The presence of these defect vacancies makes it possible to achieve multi-lattice doping designs in this type of matrix. This is because when a vacancy is near or far from the activator, it changes the coordination number of its anion, i.e., the symmetry of the coordination polyhedron; this change in the local crystal field of the doped lattice site modulates the spectral characteristics of rare-earth ions, causing differences in excitation and emission spectra, fluorescence lifetime, etc. This provides a theoretical basis for multi-lattice rare-earth doping of single nanocrystals. It is worth mentioning that low lattice site symmetry is conducive to the occurrence of induced electric dipole transitions in trivalent (3+) rare-earth ions, increasing the radiative transition rate, reducing fluorescence lifetime, and producing efficient luminescence.

[0005] Eu 3+ It is an important "traditional" red light emission center, with magnetic dipole transitions in the 4f configuration in many matrices, including ZrO2. 5 D0→ 7 F1) and forced electric dipole transition ( 5 D0→ 7 F2 can produce strong orange or red light in the 585-650 nm range, but the 4f-4f transition of rare earth ions is parity forbidden, and its absorption in the ultraviolet, near-ultraviolet, and blue light regions is linear, with low oscillator strength; how can additional energy be introduced into the matrix lattice to reach Eu? 3+ Energy transfer-allowing absorption groups (such as nds with charge transfer (CT) properties) 0 Using configurational transition metal ions to enhance luminescence efficiency is a design based on Eu. 3+ One of the key scientific questions regarding ZrO2-doped luminescent nanocrystals is the co-doped sensitized luminescence design concept, which will greatly broaden the application of rare-earth Eu... 3+ The effective spectral response range of the luminescent activator enhances the applicability of ZrO2 luminescent nanocrystals in bioimaging, fluorescent information encoding, fluorescent inks, fluorescent sensing, biosensors, electronic printing, and luminescent anti-counterfeiting.

[0006] Currently, regarding Eu 3+ While there are numerous reports on luminescent ZrO2-doped nanocrystals, there has been no breakthrough progress in areas such as multi-site doping design, co-doping to broaden the excitation wavelength range, and corresponding nanocrystal preparation methods. Therefore, there is an urgent need to investigate a nanocrystal preparation method using tetragonal ZrO2 as a matrix and incorporating two or more Eu atoms. 3+ The invention relates to luminescent nanocrystals with strong and broad excitation wavelength ranges at doped ion lattice sites, their preparation methods, and their applications. Summary of the Invention

[0007] In view of this, it is necessary to provide a Eu technology that addresses the shortcomings of existing technologies. 3+ Zirconia luminescent nanocrystals co-doped with other ions, their preparation methods, and applications; these nanocrystals use tetragonal ZrO2 as a matrix to achieve Eu luminescence. 3+ Simultaneously with ion dual-lattice doping, another sensitizer significantly broadens the excitation wavelength range; moreover, the prepared nanocrystals are small in size, narrow in distribution, and exhibit good colloidal stability. The prepared nanocrystals can meet various application requirements and can be used in fields such as fluorescence bioimaging, fluorescence information encoding, fluorescence ink, fluorescence sensing, biosensing, electronic printing, and luminescent anti-counterfeiting.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] In a first aspect, the present invention provides a luminescent nanocrystalline material having the general chemical formula Zr. 1-x-y Ti x Eu y O 2-0.5y ; among which, 0 <x≤0.08,0<y≤0.05。

[0010] Preferably, 0.0025≤x≤0.057, 0.004≤y≤0.04;

[0011] The luminescent nanocrystalline material is a doped tetragonal zirconium oxide luminescent nanocrystalline material with space group P42 / nmc.

[0012] Preferably, its chemical formula is Zr. 0.973 Ti 0.017 Eu 0.01 O 1.995 Zr 0.979 Ti 0.017 Eu 0.004 O 1.998 Zr 0.963 Ti 0.017 Eu 0.02 O 1.99 Zr 0.943 Ti 0.017 Eu 0.04 O 1.98 Zr 0.963 Ti 0.027 Eu 0.01 O 1.995 Zr 0.933 Ti 0.057 Eu 0.01 O 1.995 Zr 0.985 Ti 0.005 Eu 0.01 O 1.995 Zr 0.9875 Ti0.0025 Eu 0.01 O 1.995 Any one of them.

[0013] Secondly, the present invention also provides a method for preparing the aforementioned luminescent nanocrystalline material, comprising the following steps:

[0014] The Zr source was added to the first solvent and stirred to obtain the first solution;

[0015] Add the Eu source to the first solution and stir to obtain the second solution;

[0016] The Ti source was added to the second solution and stirred to obtain the third solution;

[0017] Add acetic acid and water to the third solution, stir, and carry out a hydrolysis reaction to obtain the fourth solution;

[0018] The fourth solution was placed in a reaction vessel for a solvothermal reaction, followed by solid-liquid separation, washing, and drying to obtain luminescent nanocrystalline materials.

[0019] Preferably, in the method for preparing the luminescent nanocrystalline material, the step of placing the fourth solution in a reaction vessel and carrying out a solvothermal reaction is performed at a reaction temperature of 240–280°C for 8–12 hours.

[0020] Preferably, in the method for preparing the luminescent nanocrystalline material, the first solvent includes at least one of n-propanol, isopropanol, and n-butanol.

[0021] Preferably, in the method for preparing the luminescent nanocrystalline material, the Zr source is an alkoxide liquid containing Zr, and the Zr-containing alkoxide liquid includes at least one of the following: a zirconium n-propoxide solution in n-propanol, a zirconium isopropoxide solution, and a zirconium n-butoxide solution in n-butanol.

[0022] And / or, the Eu source is a solution containing Eu, and the solution containing Eu includes at least one of europium-containing n-propanol solution, europium-containing isopropanol solution, and europium-containing n-butanol solution;

[0023] And / or, the Ti source is an alkoxide liquid containing Ti, wherein the Ti-containing alkoxide liquid includes at least one of titanium n-propoxide, isopropyl titanate, n-butyl titanate, a n-propanol solution of titanium n-propoxide, an isopropanol solution of isopropyl titanate, and a n-butanol solution of n-butyl titanate.

[0024] Preferably, in the method for preparing the luminescent nanocrystalline material, the method for preparing the solution containing Eu element is as follows: dissolving a solid compound containing Eu element into a second solvent to obtain a solution containing Eu element, wherein the second solvent includes at least one of n-propanol, isopropanol and n-butanol;

[0025] The Eu ion concentration in the solution containing Eu element is 0.01–0.5 mol / L;

[0026] The solid compound containing Eu includes at least one of europium nitrate, europium chloride, europium nitrate containing water of crystallization, and europium chloride containing water of crystallization.

[0027] Preferably, in the method for preparing the luminescent nanocrystalline material, the volume ratio of the first solvent, acetic acid, and water is (50-70):(0.1-0.3):(0.3-0.5).

[0028] During the process of obtaining the first, second, third, and fourth solutions by stirring, the stirring time is 5 to 15 minutes.

[0029] Thirdly, the present invention also provides the application of the luminescent nanocrystalline material or the luminescent nanocrystalline material prepared by the preparation method described above in non-contact temperature detection, fluorescence bioimaging, information encoding, fluorescent ink, fluorescence sensing, biosensing, electronic printing, luminescent anti-counterfeiting, and the preparation of luminescent devices.

[0030] The luminescent nanocrystalline material and its preparation method of the present invention have the following advantages over the prior art:

[0031] 1. The luminescent nanocrystalline material of the present invention utilizes low-lattice-symmetry tetragonal ZrO2 as an equivalent Ti. 4+ Doped ions and heterovalent Eu 3+ The matrix of doped ions, in which Eu 3+ Ions are compensated for by oxygen vacancies; in luminescent nanocrystalline materials, Eu 3+ Simultaneously occupying two lattice sites of different symmetries: one is a high-symmetry site coordinated by eight oxygen ions (referred to as Eu(I) in this invention), and the other is a low-symmetry site coordinated by seven oxygen ions, adjacent to oxygen vacancies (referred to as Eu(II) in this invention); the main peaks of the excitation bands, emission lines, and fluorescence lifetimes of Eu(I) and Eu(II) differ significantly and are easily distinguishable; in the lattice, the doped ions are not randomly distributed, Ti 4+ Preferential association with Eu(II); utilize O 2- →Ti 4+ Charge transfer excitation to Eu 3+ The unique energy transfer between ions enables Eu 3+ This results in highly efficient light emission and a wider effective excitation wavelength range. 2- →Ti 4+Charge-transfer transitions are electric dipole-allowed transitions with a large absorption cross section, enabling broadband white light emission at low temperatures and exhibiting high temperature sensitivity. The luminescent nanocrystals of this invention are small in size and narrowly distributed, showing good dispersibility in water and ethanol, and good colloidal stability. At room temperature, the doped zirconia nanocrystals of this invention exhibit strong excitation in the ultraviolet region (200-360 nm), producing characteristic red light emission of Eu(I) and Eu(II). At low temperatures, temperature-sensitive Ti can be simultaneously generated. 3+ →O - Eu has wide-bandgap charge transfer emission and low temperature sensitivity. 3+ The narrow-band sharp-line emission exhibits a temperature-dependent relationship between the strong fluorescence intensity ratio of the two components. The luminescent nanocrystalline material of this invention can be applied to non-contact temperature sensing, as well as other fields such as fluorescence sensing, fluorescence bioimaging, fluorescence information encoding, fluorescence ink, biosensing, electronic printing, luminescent anti-counterfeiting, and the fabrication of luminescent devices.

[0032] 2. The method for preparing the luminescent nanocrystalline material of the present invention adopts a solvothermal synthesis method, which is simple to operate, has low equipment requirements, low production cost, and the prepared zirconia luminescent nanocrystalline material has stable physicochemical properties. It does not deteriorate in oxygen, humid and relatively high temperature environments, and is suitable for long-term high-temperature operation. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figures 1-2 The XRD patterns of the luminescent nanocrystalline materials in Examples 1-4 and 6 are shown.

[0035] Figure 3 Zr, the luminescent nanocrystalline material in Example 1 0.973 Ti 0.017 Eu 0.01 O 1.995 Low-magnification transmission electron microscope image;

[0036] Figure 4 Zr, the luminescent nanocrystalline material in Example 1 0.973 Ti 0.017 Eu 0.01 O 1.995 The histogram of the size statistical distribution and its Gaussian fitting curve;

[0037] Figure 5Zr, the luminescent nanocrystalline material in Example 1 0.973 Ti 0.017 Eu 0.01 O 1.995 High-resolution transmission electron microscope images;

[0038] Figure 6 Zr, the luminescent nanocrystalline material in Example 1 0.973 Ti 0.017 Eu 0.01 O 1.995 Room temperature emission spectra under excitation at different wavelengths;

[0039] Figure 7 Zr, the luminescent nanocrystalline material in Example 1 0.973 Ti 0.017 Eu 0.01 O 1.995 Room temperature excitation spectra at different monitoring wavelengths;

[0040] Figure 8 Zr, the luminescent nanocrystalline material in Example 1 0.973 Ti 0.017 Eu 0.01 O 1.995 When Eu(I) and Eu(II) are primarily excited respectively, Eu 3+ Ionic 5 The room temperature fluorescence decay curve of the D0 level;

[0041] Figure 9 Zr, the luminescent nanocrystalline material in Example 4 0.943 Ti 0.017 Eu 0.04 O 1.98 When Eu(I) and Eu(II) are primarily excited respectively, Eu 3+ Ionic 5 The room temperature fluorescence decay curve of the D0 level;

[0042] Figure 10 The room-temperature excitation spectra of the luminescent nanocrystal materials in Examples 1-4 at the main monitoring Eu(I) emission peak at 607 nm are shown.

[0043] Figure 11 The room-temperature excitation spectra of the luminescent nanocrystalline materials in Examples 1-4 at the main monitoring Eu(II) emission peak at 614 nm are shown.

[0044] Figure 12 Zr, the luminescent nanocrystalline material in Example 2 0.979 Ti 0.017 Eu 0.004 O 1.998Temperature-variable emission spectra under excitation at a wavelength of 310 nm within a low temperature range of 130-230 K.

[0045] Figure 13 Zr, the luminescent nanocrystalline material in Example 2 0.979 Ti 0.017 Eu 0.004 O 1.998 exist Figure 12 In the temperature-dependent emission spectrum, Ti 3+ →O - Charge transfer CT (Ti 3+ →O - The integral intensity of broadband emission in the 450-580 nm spectral region and Eu 3+ of 5 D0- 7 The integral intensity ratio of the luminescence intensity in the 690-725 nm spectral region of the F4 transition (FIR(I)) 450-580 / I 690-725 The data points and the curve fitted using the FIR-T function;

[0046] Figure 14 Zr, the luminescent nanocrystalline material in Example 2 0.979 Ti 0.017 Eu 0.004 O 1.998 exist Figure 13 Medium FIR(I 450-580 / I 690-725 The absolute and relative sensitivities at different temperatures under the T-function condition and the corresponding fitting curves;

[0047] Figure 15 The room-temperature excitation spectra of the luminescent nanocrystal materials in Examples 1, 5-6 at the main monitoring Eu(I) emission peak of 607 nm are shown.

[0048] Figure 16 The room-temperature excitation spectra of the luminescent nanocrystals in Examples 1, 5-6 when the main emission peak of Eu(II) at 614 nm is monitored.

[0049] Figure 17 The XRD patterns of the luminescent nanocrystalline materials in Example 1 and Comparative Example 1 are shown.

[0050] Figure 18 For the luminescent nanocrystalline material Zr in Comparative Example 1 0.99 Eu 0.01 O 1.995 Room temperature emission spectra under excitation at different wavelengths;

[0051] Figure 19 For the luminescent nanocrystalline material Zr in Comparative Example 1 0.99 Eu0.01 O 1.995 Room temperature excitation spectra at different monitoring wavelengths. Detailed Implementation

[0052] The technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0053] The following provides a detailed description of each example. It should be noted that the order of description of the embodiments below is not intended to limit the preferred order of the embodiments. Furthermore, in the description of this application, the term "comprising" means "including but not limited to". Various embodiments of the present invention may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a rigid limitation on the scope of the invention; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single digits within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Additionally, whenever a numerical range is indicated herein, it means including any referenced number (fraction or integer) within the indicated range.

[0054] Tetragonal ZrO2 is a partially stable form of zirconium dioxide, and there are currently two main pathways to ensure its stability at room temperature and under normal pressure. One is through chemical doping with heterovalent cations (such as rare earth ions, Sc). 3+ Ca 2+ or Mg 2+The effects of this critical size effect are twofold: firstly, it induces charge-compensating oxygen vacancies; secondly, it reduces the grain size to below a critical value. Studies have found that, without chemical doping, there exists a critical grain size for phase transformation between the monoclinic and tetragonal phases, depending on the preparation method and conditions. The reported critical size ranges from 9 to 30 nm [Phys.Rev.B 2005,71,115408.]. The mechanism of this critical size effect is not yet fully understood, but it mainly includes two factors: the surface free energy of the tetragonal phase is lower than that of the monoclinic phase, and oxygen ion vacancies assist in the nucleation of tetragonal phase grains (which can be called primary oxygen vacancies) [J.Am.Ceram.Soc.1983,66,11-14; J.Am.Ceram.Soc.1990,73,3528-3530.]. Therefore, oxygen anion vacancies play a crucial role in the structural stabilization of the tetragonal phase. For doped nanocrystals, primary oxygen vacancies and compensating oxygen vacancies can coexist, promoting phase stabilization. For tetragonal ZrO2, based on oxygen vacancies and Zr 4+ The relative positions of cation sites indicate that one discrete oxygen vacancy can generate four nearest-neighbor seven-coordinate Zr. 4+ Cation lattice site (CN7) and 28 next nearest neighbor octagonal Zr 4+ Cation site (CN8). Clearly, when the activator Eu... 3+ Doping into the matrix lattice occupies Zr 4+ When at a lattice site, it has two possible coordination sites: CN7 and CN8. The difference in local symmetry will significantly modulate its 4f level within the shell, thus exhibiting different spectral energy distributions and fluorescence dynamics. Additionally, O 2- Vacancies can induce spatial relaxation of neighboring oxygen ions, indirectly altering the symmetry of the cation lattice site. One O 2- The removal of ions causes the nearest neighboring oxygen ions to relax in different directions in an attempt to achieve a new structural equilibrium. The displacement of atoms from their "ideal" positions, in turn, alters the symmetry of the cation lattice. Furthermore, longer-range interactions, such as vacancy-vacancy, cation-vacancy, or cation-cation interactions, may occur; finally, the general properties of nanocrystals, including high surface stress and surface disorder, all contribute to a variety of lattice symmetries. 3+ The generation of.

[0055] In tetragonal ZrO2, Ti is doped 4+ Ions (closed-shell 3d) 0 (Electronic configuration) will form TiO8 12- Ionic groups that can generate electric dipole-permissible O 2- →Ti 4+ Charge transfer transitions have large absorption cross sections and wide spectral bandwidths; when combined with Eu... 3+ When they are neighbors, a flow towards Eu can occur. 3+Efficient energy transfer generates Eu 3+ with narrow-band sharp-line red light emission. This energy transfer can, on the one hand, broaden the effective spectral response range of the activator Eu 3+ ; on the other hand, it is conducive to the identification of Eu with different coordination symmetries 3+ .

[0056] Based on the above principle, the present invention provides a luminescent nanocrystal material with a chemical general formula of Zr 1-x- y Ti x Eu y O 2-0.5y ; where 0 < x ≤ 0.08 and 0 < y ≤ 0.05, and it is a doped tetragonal zirconia luminescent nanocrystal material

[0057] In some embodiments, 0.0025 ≤ x ≤ 0.057 and 0.004 ≤ y ≤ 0.04; the luminescent nanocrystal material is a doped tetragonal zirconia luminescent nanocrystal material with a space group of P42 / nmc

[0058] In some embodiments, its chemical formula is Zr 0.973 Ti 0.017 Eu 0.01 O 1.995 Zr 0.979 Ti 0.017 Eu 0.004 O 1.998 Zr 0.963 Ti 0.017 Eu 0.02 O 1.99 Zr 0.943 Ti 0.017 Eu 0.04 O 1.98 Zr 0.963 Ti 0.027 Eu 0.01 O 1.995 Zr 0.933 Ti 0.057 Eu 0.01 O 1.995 Zr 0.985 Ti 0.005 Eu 0.01 O 1.995 Zr 0.9875 Ti 0.0025 Eu 0.01 O 1.995 any one of them

[0059] The doped zirconia luminescent nanocrystal material of the present invention utilizes low lattice symmetry tetragonal ZrO2 as an equivalent Ti 4 + doping ion and a heterovalent Eu3+ The matrix of doped ions, in which Eu 3+ Ions are compensated for by oxygen vacancies; in luminescent nanocrystalline materials, Eu 3+ Simultaneously occupying two types of lattice sites with different symmetries: one is a high-symmetry lattice site coordinated by eight oxygen ions (referred to as Eu(I)(CN8) in this invention), and the other is a low-symmetry lattice site closely adjacent to the oxygen vacancy, coordinated by seven oxygen ions (referred to as Eu(II)(CN7) in this invention); their excitation band main peak, emission line main peak, and fluorescence lifetime differ greatly and are easily distinguishable; in the lattice, the doped Ti 4+ With Eu 3+ The ions are not randomly distributed; Ti 4+ Preferential association with Eu(II), can occur from O 2- →Ti 4+ Charge transfer excitation to Eu 3+ Effective energy transfer, broadening Eu 3+ This effectively expands the excitation wavelength range and improves luminous efficiency. 2- →Ti 4+ Charge transfer transitions are allowed transitions of electric dipoles, have a large absorption cross section, can produce broadband white light emission at low temperatures, and have high temperature sensitivity.

[0060] The doped zirconia luminescent nanocrystal material of this invention belongs to the tetragonal phase of zirconia. The nanocrystals are small (approximately 5 nm) and narrowly distributed (the size distribution follows a Gaussian distribution, with a statistically significant peak size of 4.78 nm and a full width at half maximum (FWHM) of 2.5 nm). It exhibits good dispersibility in water and ethanol and good colloidal stability. At room temperature, the doped zirconia nanocrystals of this invention show strong excitation in the ultraviolet region (200-360 nm), producing bright Eu(I) and Eu(II) characteristic red light emission. At low temperatures, temperature-sensitive Ti can be simultaneously generated. 3+ →O - Eu has wide-bandgap charge transfer emission and low temperature sensitivity. 3+ The narrow-band sharp-line emission and the strong fluorescence intensity ratio between the two exhibit a certain temperature-dependent function relationship, which can be used for temperature sensing.

[0061] Based on the same inventive concept, the present invention also provides a method for preparing the above-mentioned luminescent nanocrystalline material, comprising the following steps:

[0062] S1. Add Zr source: Add Zr source to the first solvent and stir to obtain the first solution;

[0063] S2. Add Eu source: Add Eu source to the first solution and stir to obtain the second solution;

[0064] S3. Add Ti source: Add Ti source to the second solution and stir to obtain the third solution;

[0065] S4. Hydrolysis reaction: Add acetic acid and water to the third solution, stir, and carry out the hydrolysis reaction to obtain the fourth solution;

[0066] S5. Solvothermal reaction: The fourth solution is placed in a reaction vessel to carry out a solvothermal reaction, followed by solid-liquid separation, washing, and drying to obtain luminescent nanocrystalline materials.

[0067] Specifically, in the above embodiments, the Zr source can be either a compound containing Zr or a solution containing Zr; the Eu source can be either a compound containing Eu or a solution containing Eu; and the Ti source can be either a compound containing Ti or a solution containing Ti.

[0068] In some embodiments, in the step of placing the fourth solution in a reaction vessel and carrying out a solvothermal reaction, the reaction temperature is 240–280°C and the time is 8–12 h.

[0069] In some embodiments, the first solvent includes at least one of n-propanol, isopropanol, and n-butanol.

[0070] In some embodiments, the Zr source is an alkoxide liquid containing Zr, which includes at least one of zirconium n-propoxide in n-propanol solution, zirconium isopropoxide, and zirconium n-butoxide in n-butanol solution.

[0071] In some embodiments, the Eu source is a solution containing Eu, which includes at least one of a europium-containing n-propanol solution, a europium-containing isopropanol solution, and a europium-containing n-butanol solution.

[0072] In some embodiments, the Ti source is an alkoxide liquid containing Ti, which includes at least one of titanium n-propoxide, isopropyl titanate, n-butyl titanate, a n-propanol solution of titanium n-propoxide, an isopropanol solution of isopropyl titanate, and a n-butanol solution of n-butyl titanate.

[0073] In some embodiments, a solid compound containing Eu is dissolved in a second solvent to obtain a solution containing Eu, wherein the second solvent includes at least one of n-propanol, isopropanol, and n-butanol.

[0074] In some embodiments, the concentration of Eu ions in the solution containing Eu is 0.01–0.5 mol / L;

[0075] In some embodiments, the solid compound containing Eu includes at least one of europium nitrate, europium chloride, europium nitrate containing water of crystallization, and europium chloride containing water of crystallization.

[0076] In some embodiments, the volume ratio of the first solvent, acetic acid, and water is (50–70):(0.1–0.3):(0.3–0.5);

[0077] In some embodiments, the stirring time is 5 to 15 minutes during the process of obtaining the first solution, the second solution, the third solution, and the fourth solution.

[0078] In some embodiments, the fourth solution is placed in a reaction vessel for a solvothermal reaction. After the reaction is complete, the temperature is lowered to room temperature, the reaction vessel is opened, and the precipitate mixture in the reaction vessel is separated by centrifugation, washed with ethanol, and dried. The resulting white precipitate is Ti. 4+ / Eu 3+ Co-doped zirconia luminescent nanocrystals exhibit good dispersibility and colloidal stability in water and ethanol.

[0079] In some embodiments, the fourth solution is placed in a reaction vessel for a solvothermal reaction, followed by solid-liquid separation, washing, and drying, wherein the drying temperature is 60–80°C.

[0080] In some embodiments, the method for preparing luminescent nanocrystalline materials includes the following steps:

[0081] S1. Add Zr source: Take Zr source according to stoichiometric ratio, disperse it in the first solvent under magnetic stirring, and continue magnetic stirring for 5-15 minutes after adding to obtain the first solution.

[0082] S2. Add Eu source: Take Eu source according to stoichiometry and add it to the first solution in S1 under magnetic stirring. Continue magnetic stirring for 5-15 minutes after adding to obtain the second solution.

[0083] S3. Add Ti source: Take Ti source according to stoichiometric ratio, add it to the second solution in S2 under magnetic stirring, and continue magnetic stirring for 5-15 minutes after addition to obtain the third solution.

[0084] S4. Hydrolysis reaction: Under magnetic stirring, acetic acid and water are added to the third solution. After addition, magnetic stirring is continued for 5 to 15 minutes to carry out the hydrolysis reaction and obtain the fourth solution.

[0085] S5. Solvothermal reaction: The fourth solution is placed in a reaction vessel to carry out a solvothermal reaction, followed by solid-liquid separation, washing, and drying to obtain luminescent nanocrystalline materials.

[0086] The nanocrystals prepared using the method of this invention have small size, narrow distribution, good dispersibility in water and ethanol, and good colloidal stability. At room temperature, the doped zirconia nanocrystals of this invention exhibit strong excitation in the ultraviolet region (200-360 nm), producing characteristic red light emission of Eu(I) and Eu(II). At low temperatures, temperature-sensitive Ti can be simultaneously generated. 3+ →O - Eu has wide-bandgap charge transfer emission and low temperature sensitivity. 3+ The narrow-band sharp-line emission exhibits a temperature-dependent ratio in terms of fluorescence intensity. The method for preparing the luminescent nanocrystalline material of this invention employs a solvothermal synthesis, which is simple to operate, requires minimal equipment, and has low production costs. Furthermore, the prepared zirconia luminescent nanocrystalline material exhibits stable physicochemical properties, showing no deterioration under oxygen, humidity, and relatively high temperature environments, making it suitable for prolonged high-temperature operation.

[0087] Based on the same inventive concept, the present invention also provides an application of the above-mentioned luminescent nanocrystalline material or the luminescent nanocrystalline material prepared by the above-mentioned preparation method in non-contact temperature detection, fluorescence bioimaging, information encoding, fluorescent ink, fluorescence sensing, biosensing, electronic printing, luminescent anti-counterfeiting, and luminescent device fabrication.

[0088] The following detailed embodiments further illustrate the luminescent nanocrystalline materials, their preparation methods, and applications. This section further explains the invention in conjunction with specific embodiments, but should not be construed as limiting the invention. Unless otherwise specified, the techniques used in the embodiments are conventional methods well known to those skilled in the art. Unless otherwise specified, the reagents, methods, and equipment used in this invention are conventional reagents, methods, and equipment in the art.

[0089] Example 1

[0090] This embodiment provides a luminescent nanocrystalline material with the chemical formula Zr. 0.973 Ti 0.017 Eu 0.01 O 1.995 .

[0091] The luminescent nanocrystalline material Zr in Example 1 0.973 Ti 0.017 Eu 0.01 O 1.995 The preparation method includes the following steps:

[0092] S1. Take 2 mL of n-butanol solution containing 80 wt.% zirconium n-butoxide and add it to 60 mL of n-butanol solvent under magnetic stirring. Continue magnetic stirring for 10 min to obtain the first solution.

[0093] S2. Under magnetic stirring, weigh an appropriate amount of Eu(NO3)·6H2O powder and add it to n-butanol solvent to prepare a 0.02 mol / L Eu solution. 3+ A n-butanol solution containing ions;

[0094] Under magnetic stirring, 2.25 mL of Eu was added. 3+ The n-butanol solution of the ions was added to the first solution in S1, and the magnetic stirring was continued for 10 min to obtain the second solution;

[0095] S3. Under magnetic stirring, add 26 μL of tetrabutyl titanate to the second solution in S2, and continue magnetic stirring for 10 min to obtain the third solution.

[0096] S4. Under magnetic stirring, add 0.2 mL of glacial acetic acid (in liquid form) and 0.4 mL of water to the third solution in S3, and continue magnetic stirring for 10 min to carry out the hydrolysis reaction to obtain the fourth solution.

[0097] S5. Place the fourth solution from S4 into a reaction vessel and maintain the temperature at 260℃ for 10 hours. After the reaction is complete and the temperature is lowered to room temperature, centrifuge the precipitate mixture in the reaction vessel and wash it with ethanol. The resulting white precipitate is Zr. 0.973 Ti 0.017 Eu 0.01 O 1.995 Zirconia-doped luminescent nanocrystals exhibit good dispersibility and colloidal stability in water and ethanol; after drying at 60℃, Zr is obtained. 0.973 Ti 0.017 Eu 0.01 O 1.995 Zirconia-doped luminescent nanocrystal powder.

[0098] Example 2

[0099] This embodiment provides a luminescent nanocrystalline material with the chemical formula Zr. 0.979 Ti 0.017 Eu 0.004 O 1.998 .

[0100] The luminescent nanocrystalline material Zr in Example 2 0.979 Ti 0.017 Eu 0.004 O 1.998 The preparation method includes: measuring a certain volume of Zr source (80 wt.% zirconium n-butoxide in n-butanol solution) and Eu source (0.02 mol / L Eu) according to the stoichiometric ratio. 3+The solution of n-butanol (containing ions) and Ti source (n-butyl titanate) are prepared to meet the stoichiometric ratio; other preparation process controls, such as the type and volume of reaction solvent, magnetic stirring time, order of raw material addition, reactor volume, solvothermal reaction temperature and time, washing and drying conditions, are the same as in Example 1.

[0101] Example 3

[0102] This embodiment provides a luminescent nanocrystalline material with the chemical formula Zr. 0.963 Ti 0.017 Eu 0.02 O 1.99 .

[0103] The luminescent nanocrystalline material Zr in Example 3 0.963 Ti 0.017 Eu 0.02 O 1.99 The preparation method includes: measuring a certain volume of Zr source (80 wt.% zirconium n-butoxide in n-butanol solution) and Eu source (0.02 mol / L Eu) according to the stoichiometric ratio. 3+ The solution of n-butanol (containing ions) and Ti source (n-butyl titanate) are prepared to meet the stoichiometric ratio; other preparation process controls, such as the type and volume of reaction solvent, magnetic stirring time, order of raw material addition, reactor volume, solvothermal reaction temperature and time, washing and drying conditions, are the same as in Example 1.

[0104] Example 4

[0105] This embodiment provides a luminescent nanocrystalline material with the chemical formula Zr. 0.943 Ti 0.017 Eu 0.04 O 1.98 .

[0106] The luminescent nanocrystalline material Zr in Example 4 0.943 Ti 0.017 Eu 0.04 O 1.98 The preparation method includes: measuring a certain volume of Zr source (80 wt.% zirconium n-butoxide in n-butanol solution) and Eu source (0.02 mol / L Eu) according to the stoichiometric ratio. 3+ The solution of n-butanol (containing ions) and Ti source (n-butyl titanate) are prepared to meet the stoichiometric ratio; other preparation process controls, such as the type and volume of reaction solvent, magnetic stirring time, order of raw material addition, reactor volume, solvothermal reaction temperature and time, washing and drying conditions, are the same as in Example 1.

[0107] Example 5

[0108] This embodiment provides a luminescent nanocrystalline material with the chemical formula Zr. 0.963Ti 0.027 Eu 0.01 O 1.995 .

[0109] The luminescent nanocrystalline material Zr in Example 5 0.963 Ti 0.027 Eu 0.01 O 1.995 The preparation method includes: measuring a certain volume of Zr source (80 wt.% zirconium n-butoxide in n-butanol solution) and Eu source (0.02 mol / L Eu) according to the stoichiometric ratio. 3+ The solution of n-butanol (containing ions) and Ti source (n-butyl titanate) are prepared to meet the stoichiometric ratio; other preparation process controls, such as the type and volume of reaction solvent, magnetic stirring time, order of raw material addition, reactor volume, solvothermal reaction temperature and time, washing and drying conditions, are the same as in Example 1.

[0110] Example 6

[0111] This embodiment provides a luminescent nanocrystalline material with the chemical formula Zr. 0.933 Ti 0.057 Eu 0.01 O 1.995 .

[0112] The luminescent nanocrystalline material Zr in Example 6 0.933 Ti 0.057 Eu 0.01 O 1.995 The preparation method includes: measuring a certain volume of Zr source (80 wt.% zirconium n-butoxide in n-butanol solution) and Eu source (0.02 mol / L Eu) according to the stoichiometric ratio. 3+ The solution of n-butanol (containing ions) and Ti source (n-butyl titanate) are prepared to meet the stoichiometric ratio; other preparation process controls, such as the type and volume of reaction solvent, magnetic stirring time, order of raw material addition, reactor volume, solvothermal reaction temperature and time, washing and drying conditions, are the same as in Example 1.

[0113] Example 7

[0114] This embodiment provides a luminescent nanocrystalline material with the chemical formula Zr. 0.973 Ti 0.017 Eu 0.01 O 1.995 .

[0115] The luminescent nanocrystalline material Zr in Example 7 0.973 Ti 0.017 Eu 0.01 O 1.995 The preparation method includes the following steps:

[0116] S1. Under magnetic stirring conditions, weigh 1.6958 g of zirconium isopropoxide, add it to 60 mL of isopropanol solvent, and continue magnetic stirring for 10 min to obtain the first solution.

[0117] S2. Under magnetic stirring, weigh an appropriate amount of EuCl3·6H2O powder and add it to isopropanol solvent to prepare 0.02 mol / L EuCl3·6H2O. 3+ Isopropanol solution containing ions;

[0118] Under magnetic stirring, 2.25 mL of Eu was added. 3+ The isopropanol solution of the ions was added to the first solution in S1, and the magnetic stirring was continued for 10 minutes to obtain the second solution.

[0119] S3. Under magnetic stirring, add 22.6 μL of isopropyl titanate to the second solution in S2, and continue magnetic stirring for 10 min to obtain the third solution.

[0120] S4. Under magnetic stirring, add 0.2 mL of glacial acetic acid (in liquid form) and 0.4 mL of water to the third solution in S3, and continue magnetic stirring for 10 min to carry out the hydrolysis reaction to obtain the fourth solution.

[0121] S5. Place the fourth solution from S4 into a reaction vessel and maintain the temperature at 260℃ for 10 hours. After the reaction is complete and the temperature is lowered to room temperature, centrifuge the precipitate mixture in the reaction vessel and wash it with ethanol. The resulting white precipitate is Zr. 0.973 Ti 0.017 Eu 0.01 O 1.995 Zirconia-doped luminescent nanocrystals exhibit good dispersibility and colloidal stability in water and ethanol; after drying at 60℃, Zr is obtained. 0.973 Ti 0.017 Eu 0.01 O 1.995 Zirconia-doped luminescent nanocrystal powder.

[0122] Example 8

[0123] This embodiment provides a luminescent nanocrystalline material with the chemical formula Zr. 0.973 Ti 0.017 Eu 0.01 O 1.995 .

[0124] The luminescent nanocrystalline material Zr in Example 8 0.973 Ti 0.017 Eu 0.01 O 1.995 The preparation method includes the following steps:

[0125] S1. Under magnetic stirring, 1.96 mL of n-propanol solution containing 70 wt.% zirconium propoxide was transferred and added to 60 mL of n-propanol solvent. The mixture was then stirred magnetically for 10 min to obtain the first solution.

[0126] S2. Under magnetic stirring, weigh an appropriate amount of Eu(NO3)·6H2O powder and add it to n-propanol solvent to prepare 0.02 mol / L Eu. 3+ A solution of n-propanol containing ions;

[0127] Under magnetic stirring, 2.25 mL of Eu was added. 3+ The n-propanol solution of the ions was added to the first solution in S1, and the magnetic stirring was continued for 10 minutes to obtain the second solution.

[0128] S3. Under magnetic stirring, add 21 μL of n-propoxide titanium to the second solution in S2, and continue magnetic stirring for 10 min to obtain the third solution.

[0129] S4. Under magnetic stirring, add 0.2 mL of glacial acetic acid (in liquid form) and 0.4 mL of water to the third solution in S3, and continue magnetic stirring for 10 min to carry out the hydrolysis reaction to obtain the fourth solution.

[0130] S5. Place the fourth solution from S4 into a reaction vessel and maintain the temperature at 260℃ for 10 hours. After the reaction is complete and the temperature is lowered to room temperature, centrifuge the precipitate mixture in the reaction vessel and wash it with ethanol. The resulting white precipitate is Zr. 0.973 Ti 0.017 Eu 0.01 O 1.995 Zirconia-doped luminescent nanocrystals exhibit good dispersibility and colloidal stability in water and ethanol; after drying at 60℃, Zr is obtained. 0.973 Ti 0.017 Eu 0.01 O 1.995 Zirconia-doped luminescent nanocrystal powder.

[0131] Example 9

[0132] This embodiment provides a luminescent nanocrystalline material with the chemical formula Zr. 0.985 Ti 0.005 Eu 0.01 O 1.995 .

[0133] The luminescent nanocrystalline material Zr in Example 9 0.985 Ti 0.005 Eu 0.01 O 1.995The preparation method includes: measuring a certain volume of Zr source (80 wt.% zirconium n-butoxide in n-butanol solution) and Eu source (0.02 mol / L Eu) according to the stoichiometric ratio. 3+ The ions (n-butanol solution) and Ti source (n-butanol solution of titanate) are used to meet the stoichiometric ratio; other preparation process controls, such as the type and volume of reaction solvent, magnetic stirring time, order of raw material addition, reactor volume, solvothermal reaction temperature and time, washing and drying conditions, are the same as in Example 1.

[0134] Example 10

[0135] This embodiment provides a luminescent nanocrystalline material with the chemical formula Zr. 0.9875 Ti 0.0025 Eu 0.01 O 1.995 .

[0136] The luminescent nanocrystalline material Zr in Example 10 0.9875 Ti 0.0025 Eu 0.01 O 1.995 The preparation method includes: measuring a certain volume of Zr source (80 wt.% zirconium n-butoxide in n-butanol solution) and Eu source (0.02 mol / L Eu) according to the stoichiometric ratio. 3+ The ions (n-butanol solution) and Ti source (n-butanol solution of titanate) are used to meet the stoichiometric ratio; other preparation process controls, such as the type and volume of reaction solvent, magnetic stirring time, order of raw material addition, reactor volume, solvothermal reaction temperature and time, washing and drying conditions, are the same as in Example 1.

[0137] Comparative Example 1

[0138] This comparative example provides a luminescent nanocrystalline material with the chemical formula Zr. 0.99 Eu 0.01 O 1.995 Comparative Example 1: Luminescent nanocrystalline material Zr 0.99 Eu 0.01 O 1.995 The preparation method, except for lowering the solvothermal reaction temperature to 200°C in step S5, involves the same process control as in Example 1, including the type and volume of the reaction solvent, magnetic stirring time, order of raw material addition, reactor volume, solvothermal reaction time, washing, and drying conditions. In Comparative Example 1, a Ti source was added during preparation. Due to the low reaction temperature of only 200°C, Ti did not undergo a doping reaction, and the final product obtained was Zr. 0.99 Eu 0.01 O 1.995 Luminescent nanocrystalline materials.

[0139] Performance testing

[0140] Figure 1 Zr in Example 1 0.973 Ti 0.017 Eu 0.01 O 1.995 Zr in Example 2 0.979 Ti 0.017 Eu 0.004 O 1.998 In Example 3, Zr 0.963 Ti 0.017 Eu 0.02 O 1.99 Zr in Example 4 0.943 Ti 0.017 Eu 0.04 O 1.98 XRD diffraction patterns of nanocrystals, and standard card patterns of monoclinic ZrO2 (PDF#86-1451) and tetragonal ZrO2 (PDF#88-1007); Figure 2 Zr in Example 1 0.973 Ti 0.017 Eu 0.01 O 1.995 And Zr in Example 6 0.933 Ti 0.057 Eu 0.01 O 1.995 XRD diffraction patterns of nanocrystals, and standard card patterns of monoclinic ZrO2 (PDF#86-1451) and tetragonal ZrO2 (PDF#88-1007).

[0141] from Figure 1 As can be seen from Example 1, Zr 0.973 Ti 0.017 Eu 0.01 O 1.995 The peak positions and relative intensities of the X-ray diffraction (XRD) curves are consistent with those of tetragonal ZrO2 (PDF#88-1007), with space group P42 / nmc, and the main crystalline phase of the material is tetragonal zirconia; in Example 2, Zr 0.979 Ti 0.017 Eu 0.004 O 1.998 Compared with Zr in Example 1 0.973 Ti 0.017 Eu 0.01 O 1.995 The XRD diffraction patterns are similar, and the main crystalline phase of the material is tetragonal zirconia with space group P42 / nmc; Zr in Example 3 0.963 Ti 0.017 Eu 0.02 O 1.99 Compared with Zr in Example 1 0.973 Ti0.017 Eu 0.01 O 1.995 The XRD diffraction patterns are similar, and the main crystalline phase of the material is tetragonal zirconia with space group P42 / nmc; Zr in Example 4 0.943 Ti 0.017 Eu 0.04 O 1.98 Compared with Zr in Example 1 0.973 Ti 0.017 Eu 0.01 O 1.995 The XRD diffraction patterns are similar, and the main crystalline phase of the material is tetragonal zirconia with space group P42 / nmc; Zr in Example 5 0.963 Ti 0.027 Eu 0.01 O 1.995 Compared with Zr in Example 1 0.973 Ti 0.017 Eu 0.01 O 1.995 The XRD diffraction pattern is similar, and the main crystalline phase of the material is tetragonal zirconia with space group P42 / nmc. No further illustration is provided here. In Example 6, Zr... 0.933 Ti 0.057 Eu 0.01 O 1.995 Compared with Zr in Example 1 0.973 Ti 0.017 Eu 0.01 O 1.995 The XRD diffraction pattern is similar to that of the material, which has a tetragonal zirconia main crystalline phase and a space group of P42 / nmc.

[0142] Regarding the luminescent nanocrystalline material Zr in Example 1 0.973 Ti 0.017 Eu 0.01 O 1.995 The size and morphology were analyzed, and the results are as follows: Figures 3-5 As shown; Figure 3 Zr, the luminescent nanocrystalline material in Example 1 0.973 Ti 0.017 Eu 0.01 O 1.995 Low-magnification transmission electron microscope image; Figure 4 Zr, the luminescent nanocrystalline material in Example 1 0.973 Ti 0.017 Eu 0.01 O 1.995 The histogram of the size statistical distribution and its Gaussian fitting curve; Figure 5 Zr, the luminescent nanocrystalline material in Example 1 0.973 Ti 0.017 Eu 0.01 O 1.995High-resolution transmission electron microscope image.

[0143] from Figure 3 The low-magnification transmission electron microscopy images show that the luminescent nanocrystalline material consists of nanoparticles with relatively uniform morphology; its size is small (approximately 5 nm) and its distribution is narrow; Figure 3 It can be seen that the size distribution of its nanoparticles conforms to a Gaussian distribution, with a statistically significant peak size of 4.78 nm and a full width at half maximum (FWHM) of 2.5 nm; from Figure 4 The high-resolution transmission electron microscopy images show that the lattice fringes of individual nanoparticles are clear, with a lattice fringes spacing of about 0.30 nm, corresponding to the (101) crystal plane of tetragonal ZrO2. This indicates that individual nanoparticles have single-crystal characteristics, and the luminescent nanocrystalline material is easy to disperse in water and ethanol, with good colloidal stability, which can last for more than a month.

[0144] Zr in Example 2 0.979 Ti 0.017 Eu 0.004 O 1.998 In Example 3, Zr 0.963 Ti 0.017 Eu 0.02 O 1.99 Zr in Example 4 0.943 Ti 0.017 Eu 0.04 O 1.98 Zr in Example 5 0.963 Ti 0.027 Eu 0.01 O 1.995 Zr in Example 6 0.933 Ti 0.057 Eu 0.01 O 1.995 The size, morphology, dispersibility and colloidal stability of the luminescent nanocrystalline material in water and ethanol are similar to those of Zr in Example 1. 0.973 Ti 0.017 Eu 0.01 O 1.995 The results are similar, and no further illustrations are provided here.

[0145] The luminescent nanocrystalline material Zr obtained in Example 1 0.973 Ti 0.017 Eu 0.01 O 1.995 The excitation and emission spectra were analyzed, and the results are as follows: Figures 6-7 As shown. Figure 6 Zr, the luminescent nanocrystalline material in Example 1 0.973 Ti 0.017 Eu 0.01 O 1.995 Room temperature emission spectra under different wavelength excitation (λ)ex =250, 270, 310 and 330 nm); Figure 7 Zr, the luminescent nanocrystalline material in Example 1 0.973 Ti 0.017 Eu 0.01 O 1.995 Room temperature excitation spectra at different monitoring wavelengths (λ) em =607 and 614nm); Figure 6 The illustration shows the luminescent nanocrystalline material Zr in Example 1. 0.973 Ti 0.017 Eu 0.01 O 1.995 A photograph of the luminescence of a colloidal aqueous solution under 365nm ultraviolet light.

[0146] from Figure 6 As can be seen, under room temperature and different ultraviolet light wavelengths, the emission spectrum of the luminescent nanocrystalline material is mainly Eu. 3+ of 5 D0- 7 F J It exhibits sharp-line characteristic emission, but its spectral energy distribution varies with the excitation wavelength. Close observation reveals that its emission spectrum contains two sets of Eu... 3+ The typical emissions are referred to as Eu(I) and Eu(II), respectively. Short excitation wavelengths (250 and 270 nm) primarily select Eu(I) for excitation, while long excitation wavelengths (310 and 330 nm) primarily select Eu(II). The spectra measured under different wavelength excitations are the result of superimposing Eu(I) and Eu(II) in different proportions. The emission line position and assignment of Eu(I) is 592.2 nm. 5 D0→ 7 F1); 607.0, 628.0, 634.0nm( 5 D0→ 7 F2); 652.0, 660.0nm ( 5 D0→ 7 F3); 714.8nm 5 D0→ 7 F4). The emission lines of Eu(II) are located and assigned at 591.6 and 597.2 nm. 5 D0→ 7 F1); 614.0, 626.4, 631.2nm ( 5 D0→ 7 F2); 656.2nm 5 D0→ 7 F3); 713.0nm ( 5 D0→ 7F4). The emission peaks of Eu(I) and Eu(II) both originate from... 5 D0→ 7 F2-induced electric dipole transitions, located at 607 and 614 nm respectively, exhibit significant peak differences, making them easily identifiable. This is beneficial for fluorescence information encoding applications based on emission color; this single type of nanocrystal can provide two independent information encoding channels in the color dimension. (The text abruptly ends here, likely due to an incomplete sentence or missing information.) 5 D0→ 7 F2) and magnetic dipole transition ( 5 D0→ 7 The antisymmetric integral intensity ratio R = I(F1) 5 D0→ 7 F2) / I( 5 D0→ 7 From F1), it can be seen that Eu(I) occupies a relatively high symmetry lattice site and is considered to be an eight-oxygen ion coordinated lattice site (CN8); Eu(II) occupies a relatively low symmetry lattice site and is considered to be a seven-coordinate lattice site associated with an oxygen vacancy (CN7).

[0147] from Figure 6 As can be seen from the illustrations, under 365nm ultraviolet lamp excitation, the Zr obtained in Example 1... 0.973 Ti 0.017 Eu 0.01 O 1.995 The colloidal aqueous solution of nanocrystals is bright red.

[0148] from Figure 7 It can be seen that when the red emission peaks of Eu(I) and Eu(II) at 607 and 614 nm are monitored respectively, the measured Zr in Example 1 0.973 Ti 0.017 Eu 0.01 O 1.995 The excitation spectra of all of them contain a broad and strong antisymmetric band (200-360 nm) and some originating from Eu. 3+ 4f-4f sharp line ( 5 D4← 7 F0, 5 G2← 7 F0, 5 L6← 7 F0, 5 D3← 7 F0, 5 D2← 7 F0). The intensity distribution and peak values ​​of the broad bands of Eu(I) and Eu(II) are significantly different, which is advantageous for selective excitation in fields such as fluorescent labeling or information encoding. The excitation sources of the broad bands are different; for Eu(I), its peak is located at ~270 nm, mainly originating from O. 2- →Eu3+ Charge transfer excitation (CT(O)) 2- →Eu 3+ However, it also includes some weak O. 2- →Ti 4+ Charge transfer excitation (CT(O)) 2- →Ti 4+ The contribution of O is located at 290-360 nm; for Eu(II), the peak is located at ~310 nm, mainly due to O. 2- →Ti 4+ Charge transfer excitation (CT(O)) 2- →Ti 4+ However, it also includes some contributions from matrix excitation (230 nm).

[0149] The luminescent nanocrystalline material Zr obtained in Example 1 0.973 Ti 0.017 Eu 0.01 O 1.995 The fluorescence kinetics were analyzed, and the results are as follows: Figure 8 As shown. Specifically, Figure 8 Zr, the luminescent nanocrystalline material in Example 1 0.973 Ti 0.017 Eu 0.01 O 1.995 When Eu(I) and Eu(II) are primarily excited respectively, Eu 3+ Ionic 5 Room temperature fluorescence decay curve of D0 level (measurement condition for main excitation Eu(I) is λ) ex =270,λ em =607; the main measurement condition for exciting Eu(II) is λ. ex =310,λ em =614;); Figure 9 Zr, the luminescent nanocrystalline material in Example 4 0.943 Ti 0.017 Eu 0.04 O 1.98 When Eu(I) and Eu(II) are primarily excited respectively, Eu 3+ Ionic 5 Room temperature fluorescence decay curve of D0 level (measurement condition for main excitation Eu(I) is λ) ex =270,λ em =607; the main measurement condition for exciting Eu(II) is λ. ex =310,λ em =614;).

[0150] from Figure 8 It can be seen that when Eu(I) is mainly excited (λ) ex=270nm), its 5 The average lifetime of the D0 level is 5.27 ms; when Eu(II) is predominantly excited (λ ex =310nm), its 5 The average lifetime of the D0 level is 2.86 ms. This result indicates that Eu(I) has... 5 The D0 level has a longer fluorescence lifetime, and Eu(II) has a longer fluorescence lifetime. 5 The fluorescence lifetime of the D0 level is relatively short, and there is a significant difference between the two. When applied to time-resolved information encoding, the large difference in fluorescence lifetime can enable this single type of nanocrystal to provide two independent information encoding channels in the lifetime dimension.

[0151] The fluorescence kinetics of the luminescent nanocrystals obtained in Example 4 were analyzed, and the results are as follows: Figure 9 As shown. When Eu(I) and Eu(II) are mainly excited respectively, Zr in Example 4 0.943 Ti 0.017 Eu 0.04 O 1.98 Eu(I) and Eu(II) 5 The fluorescence lifetime of the D0 level is significantly longer than that of Zr in Example 1. 0.973 Ti 0.017 Eu 0.01 O 1.995 The value of Eu(I) shortens significantly, which is caused by concentration quenching. 5 The fluorescence lifetime of the D0 level is still significantly longer than that of Eu(II), and there is still a considerable difference between the two. This is consistent with the Zr level in Example 1. 0.973 Ti 0.017 Eu 0.01 O 1.995 The results are similar.

[0152] Figure 10 Zr in Example 1 0.973 Ti 0.017 Eu 0.01 O 1.995 In Example 2, Zr 0.979 Ti 0.017 Eu 0.004 O 1.998 In Example 3, Zr 0.963 Ti 0.017 Eu 0.02 O 1.99 In Example 4, Zr 0.943 Ti 0.017 Eu 0.04 O 1.98 The room-temperature excitation spectrum of nanocrystals at the main monitoring Eu(I) emission peak at 607 nm.

[0153] Figure 11 Zr in Example 1 0.973 Ti 0.017 Eu 0.01 O 1.995 In Example 2, Zr 0.979 Ti 0.017 Eu 0.004 O 1.998 In Example 3, Zr 0.963 Ti 0.017 Eu 0.02 O 1.99 In Example 4, Zr 0.943 Ti 0.017 Eu 0.04 O 1.98 The room-temperature excitation spectrum of nanocrystals at the main monitoring Eu(II) emission peak at 614 nm.

[0154] from Figures 10-11 As can be seen from the data, when the red emission peaks of Eu(I) and Eu(II) are monitored at 607 and 614 nm respectively, the Zr in Example 2... 0.979 Ti 0.017 Eu 0.004 O 1.998 The excitation spectral distribution is similar to that of Zr in Example 1. 0.973 Ti 0.017 Eu 0.01 O 1.995 The results are similar, except for the overall intensity and the broadband excitation peak (λ) of Eu(I). ex Broadband excitation peaks (λ = 270 nm) and Eu(II) ex The intensity ratio of Eu(I) to Eu(II) at 310 nm decreased. The decrease in the intensity ratio of the broadband excitation peak indicates that the relative concentrations of Eu(I) and Eu(II) in the nanocrystals decrease with increasing Eu concentration. 3+ The doping concentration varies. Lower doping concentrations result in more Eu cells occupying Eu(II) sites. 3+ The greater the relative number of Eu atoms, the higher the doping concentration, and the more Eu atoms occupy Eu(I) sites. 3+ The greater the relative quantity. When selecting excitation Eu(I) and Eu(II), Zr in Example 2 0.979 Ti 0.017 Eu 0.004 O 1.998 The emission spectral distributions of Eu(I) and Eu(II) are respectively similar to those of Zr in Example 1. 0.973 Ti 0.017 Eu 0.01 O 1.995 The results are similar, and no further illustration is provided here. When Eu(I) and Eu(II) are primarily excited respectively, Zr in Example 2... 0.979 Ti 0.017 Eu0.004 O 1.998 Eu(I) and Eu(II) 5 The fluorescence decay curves of the D0 energy level are respectively compared with those of Zr in Example 1. 0.973 Ti 0.017 Eu 0.01 O 1.995 The results are similar, and no further illustrations are provided here. In Example 3, Zr... 0.963 Ti 0.017 Eu 0.02 O 1.99 The excitation spectral distribution is similar to that of Zr in Example 1. 0.973 Ti 0.017 Eu 0.01 O 1.995 The results were similar, except that the broadband excitation intensity of Eu(I) was significantly enhanced, while the broadband excitation intensity of Eu(II) was somewhat reduced, and the broadband excitation peak (λ) of Eu(I) was also less pronounced. ex Broadband excitation peaks (λ = 270 nm) and Eu(II) ex The intensity ratio of Eu(I) to Eu(II) at 310 nm increased. The increase in the intensity ratio of the broadband excitation peak indicates that the relative concentrations of Eu(I) and Eu(II) in the nanocrystals increase with the increase of Eu(II). 3+ The doping concentration varies. Lower doping concentrations result in more Eu cells occupying Eu(II) sites. 3+ The greater the relative number of Eu atoms, the higher the doping concentration, and the more Eu atoms occupy Eu(I) sites. 3+ The greater the relative quantity. When selecting excitation Eu(I) and Eu(II), Zr in Example 3 0.963 Ti 0.017 Eu 0.02 O 1.99 The emission spectral distributions of Eu(I) and Eu(II) are respectively similar to those of Zr in Example 1. 0.973 Ti 0.017 Eu 0.01 O 1.995 The results are similar, and no further illustration is provided here. When Eu(I) and Eu(II) are primarily excited respectively, Zr in Example 3... 0.963 Ti 0.017 Eu 0.02 O 1.99 Eu(I) and Eu(II) 5 The fluorescence decay curves of the D0 energy level are respectively compared with those of Zr in Example 1. 0.973 Ti 0.017 Eu 0.01 O 1.995 The results are similar, and no further illustrations are provided here. In Example 4, Zr... 0.943 Ti 0.017 Eu 0.04O 1.98 The excitation spectral distribution is similar to that of Zr in Example 3. 0.963 Ti 0.017 Eu 0.02 O 1.99 The results were similar, except that the broadband excitation intensity of Eu(I) was further enhanced, while the broadband excitation intensity of Eu(II) was significantly reduced, and the broadband excitation peak (λ) of Eu(I) was also lower. ex Broadband excitation peaks (λ = 270 nm) and Eu(II) ex The intensity ratio at 310 nm (=310 nm) increased. The higher the doping concentration, the more Eu occupies the Eu(I) sites. 3+ The greater the relative quantity. When selecting excitation Eu(I) and Eu(II), Zr in Example 4 0.943 Ti 0.017 Eu 0.04 O 1.98 The emission spectral distributions of Eu(I) and Eu(II) are respectively similar to those of Zr in Example 1. 0.973 Ti 0.017 Eu 0.01 O 1.995 The results are similar, and no further illustrations are provided here.

[0155] At low temperature, under 310nm ultraviolet light excitation, Zr in Example 3 0.963 Ti 0.017 Eu 0.02 O 1.99 The emission spectrum and its variation with temperature are similar to those of Zr in Example 2. 0.979 Ti 0.017 Eu 0.004 O 1.998 The results are similar, and no further illustrations are provided here. Zr in Example 3 0.963 Ti 0.017 Eu 0.02 O 1.99 Luminescent nanocrystals can also be used for non-contact optical temperature sensing.

[0156] Figure 12 Zr, the luminescent nanocrystalline material in Example 2 0.979 Ti 0.017 Eu 0.004 O 1.998 Temperature-varying emission spectra (λ) under excitation at a wavelength of 310 nm within the low temperature range of 130-230 K. ex =310nm); Figure 13 Zr, the luminescent nanocrystalline material in Example 2 0.979 Ti 0.017 Eu 0.004 O 1.998 exist Figure 12In the temperature-dependent emission spectrum, Ti 3+ →O - Charge transfer CT (Ti 3+ →O - The integral intensity of broadband emission in the 450-580 nm spectral region and Eu 3+ of 5 D0- 7 The integral intensity ratio of the luminescence intensity in the 690-725 nm spectral region of the F4 transition (FIR(I)) 450-580 / I 690-725 The data points and the curve (solid line) fitted by the FIR-T function, FIR(I 450-580 / I 690-725 The T-function relationship is given in the blank space of the graph; Figure 14 The luminescent nanocrystalline material in Example 2 Figure 13 Medium FIR(I 450-580 / I 690-725 The absolute and relative sensitivities at different temperatures under the T-function condition and the corresponding fitting curves (solid lines).

[0157] Depend on Figure 12 It is known that, within the low-temperature range of 130-230K, under 310nm ultraviolet light excitation, the luminescent nanocrystalline material Zr... 0.979 Ti 0.017 Eu 0.004 O 1.998 Its emission spectrum contains Ti 3+ →O - Charge transfer CT (Ti 3+ →O - Broadband emission, with an emission peak at ~530nm, and Eu 3+ of 5 D0- 7 F J Sharp-line emission. With increasing temperature, the base CT (Ti) 3+ →O - The broadband transmission strength decreased rapidly, while Eu 3+ of 5 D0- 7 F J The emission intensity decreases relatively slowly. CT(Ti) 3+ →O - The integral intensity of luminescence in the broadband spectral region of 450-580 nm and the content of Eu 3+ of 5 D0- 7 The integral intensity ratio (FIR) value of the luminescence in the 690-725 nm spectral region of the F4 transition is I. 450-580 / I 690-725 ,like Figure 13As shown, the temperature decreases with increasing temperature in the range of 130-230K according to the following decay relationship: By the definition of absolute sensitivity: like Figure 14 As shown, the absolute sensitivity is highest at 190K, which is 0.045K. -1 Defined by relative sensitivity: like Figure 14 As shown, the relative sensitivity is highest at 230K, which is 1.9% K. -1 This indicates that the luminescent nanocrystals prepared in this invention can be used as non-contact optical temperature sensing materials.

[0158] Figure 15 Zr in Example 1 0.973 Ti 0.017 Eu 0.01 O 1.995 In Example 5, Zr 0.963 Ti 0.027 Eu 0.01 O 1.995 In Example 6, Zr 0.933 Ti 0.057 Eu 0.01 O 1.995 Room temperature excitation spectrum of nanocrystals at the main monitoring Eu(I) emission peak at 607 nm;

[0159] Figure 16 Zr in Example 1 0.973 Ti 0.017 Eu 0.01 O 1.995 In Example 5, Zr 0.963 Ti 0.027 Eu 0.01 O 1.995 In Example 6, Zr 0.933 Ti 0.057 Eu 0.01 O 1.995 The room-temperature excitation spectrum of nanocrystals at the main monitoring Eu(II) emission peak at 614 nm.

[0160] from Figures 15-16 As can be seen from the data, when the red emission peaks of Eu(I) and Eu(II) at 607 and 614 nm are monitored respectively, the Zr in Example 5... 0.963 Ti 0.027 Eu 0.01 O 1.995 The excitation spectral distribution is similar to that of Zr in Example 1. 0.973 Ti 0.017 Eu 0.01 O 1.995The results were similar, except that the broadband excitation intensity of Eu(I) was further enhanced, while the broadband excitation intensity of Eu(II) was reduced, and the broadband excitation peak (λ) of Eu(I) was also reduced. ex Broadband excitation peaks (λ = 270 nm) and Eu(II) ex The intensity ratio (310 nm) increased. This indicates that higher concentrations of Ti... 4+ Doping reduces the luminescence intensity of Eu(II). When selecting Eu(I) and Eu(II) for excitation, Zr in Example 5... 0.963 Ti 0.027 Eu 0.01 O 1.995 The emission spectral distributions of Eu(I) and Eu(II) are respectively similar to those of Zr in Example 1. 0.973 Ti 0.017 Eu 0.01 O 1.995 The results are similar, and no further illustrations are provided here.

[0161] When Eu(I) and Eu(II) are mainly excited respectively, Zr in Example 5 0.963 Ti 0.027 Eu 0.01 O 1.995 Eu(I) and Eu(II) 5 The fluorescence decay curves of the D0 energy level are respectively compared with those of Zr in Example 1. 0.973 Ti 0.017 Eu 0.01 O 1.995 The results are similar, and no further illustration is provided here. This demonstrates the fixed Eu 3+ With the concentration remaining constant, an appropriate amount of Ti is added. 4+ The effect of ion doping concentration on Eu(I) and Eu(II) 5 The fluorescence decay of the D0 level has little effect.

[0162] from Figures 15-16 As can be seen from the data, when the red emission peaks of Eu(I) and Eu(II) at 607 and 614 nm are monitored respectively, the Zr in Example 6... 0.933 Ti 0.057 Eu 0.01 O 1.995 The excitation spectral distribution is similar to that of Zr in Example 5. 0.963 Ti 0.027 Eu 0.01 O 1.98 The results were similar, except that the broadband excitation intensity of Eu(I) decreased significantly, while the broadband excitation intensity of Eu(II) decreased slightly, and the broadband excitation peak (λ) of Eu(I) was also less pronounced. ex Broadband excitation peaks (λ = 270 nm) and Eu(II)ex The intensity ratio at 310 nm (=310 nm) decreased. This indicates that higher concentrations of Ti... 4+ Doping significantly quenches the luminescence of both Eu(I) and Eu(II); the effect is more pronounced on Eu(I). When selecting excitation methods for Eu(I) and Eu(II), Zr in Example 6... 0.933 Ti 0.057 Eu 0.01 O 1.995 The emission spectral distributions of Eu(I) and Eu(II) are respectively similar to those of Zr in Example 1. 0.973 Ti 0.017 Eu 0.01 O 1.995 The results are similar, and no further illustrations are provided here.

[0163] When Eu(I) and Eu(II) are mainly excited respectively, Zr in Example 6 0.933 Ti 0.057 Eu 0.01 O 1.995 Eu(I) and Eu(II) 5 The fluorescence decay curves of the D0 energy level are respectively compared with those of Zr in Example 1. 0.973 Ti 0.017 Eu 0.01 O 1.995 The results are similar, and no further illustration is provided here. This demonstrates the fixed Eu 3+ With the concentration remaining constant, an appropriate amount of Ti is added. 4+ The effect of ion doping concentration on Eu(I) and Eu(II) 5 The fluorescence decay of the D0 level has little effect.

[0164] Furthermore, the Zr prepared in Example 7 0.973 Ti 0.017 Eu 0.01 O 1.995 Compared with the Zr prepared in Example 1 0.973 Ti 0.017 Eu 0.01 O 1.995 The XRD diffraction pattern is similar, and the main crystalline phase of the material is tetragonal zirconia with space group P42 / nmc. No further illustration is provided here. In Example 7, Zr... 0.973 Ti 0.017 Eu 0.01 O 1.995 The nanocrystal size, morphology, dispersibility and colloidal stability in water and ethanol are similar to those of Zr in Example 1. 0.973 Ti 0.017 Eu 0.01 O 1.995The results are similar, and no further illustrations are provided here. In Example 7, Zr... 0.973 Ti 0.017 Eu 0.01 O 1.995 The excitation and emission spectral distributions are similar to those of Zr in Example 1. 0.973 Ti 0.017 Eu 0.01 O 1.995 The results are similar, and no further illustrations are provided here. Zr in Example 7 0.973 Ti 0.017 Eu 0.01 O 1.995 Luminescent nanocrystals also include two types of Eu: Eu(I) and Eu(II). 3+ The ions, their respective excitation and emission spectral distributions, emission peaks, and fluorescence kinetics are similar to those of Zr in Example 1. 0.973 Ti 0.017 Eu 0.01 O 1.995 The results were similar. At low temperature, under 310nm ultraviolet light excitation, the Zr in Example 7... 0.973 Ti 0.017 Eu 0.01 O 1.995 The emission spectrum and its variation with temperature are similar to those of Zr in Example 1. 0.973 Ti 0.017 Eu 0.01 O 1.995 The results are similar, and no further illustrations are provided here. Zr in Example 7 0.973 Ti 0.017 Eu 0.01 O 1.995 Luminescent nanocrystals can also be used for non-contact optical temperature sensing.

[0165] Zr prepared in Example 8 0.973 Ti 0.017 Eu 0.01 O 1.995 Compared with Zr in Example 1 0.973 Ti 0.017 Eu 0.01 O 1.995 The XRD diffraction pattern is similar, and the main crystalline phase of the material is tetragonal zirconia with space group P42 / nmc. No further illustration is provided here. In Example 8, Zr... 0.973 Ti 0.017 Eu 0.01 O 1.995 The nanocrystal size, morphology, dispersibility and colloidal stability in water and ethanol are similar to those of Zr in Example 1. 0.973 Ti 0.017 Eu 0.01O 1.995 The results are similar, and no further illustrations are provided here. In Example 8, Zr... 0.973 Ti 0.017 Eu 0.01 O 1.995 The excitation and emission spectral distributions are similar to those of Zr in Example 1. 0.973 Ti 0.017 Eu 0.01 O 1.995 The results are similar, and no further illustrations are provided here. Zr in Example 8 0.973 Ti 0.017 Eu 0.01 O 1.995 Luminescent nanocrystals also include two types of Eu: Eu(I) and Eu(II). 3+ The ions, their respective excitation and emission spectral distributions, emission peaks, and fluorescence kinetics are similar to those of Zr in Example 1. 0.973 Ti 0.017 Eu 0.01 O 1.995 The results were similar. At low temperature, under 310nm ultraviolet light excitation, the Zr in Example 8... 0.973 Ti 0.017 Eu 0.01 O 1.995 The emission spectrum and its variation with temperature are similar to those of Zr in Example 1. 0.973 Ti 0.017 Eu 0.01 O 1.995 The results are similar, and no further illustrations are provided here. Zr in Example 8 0.973 Ti 0.017 Eu 0.01 O 1.995 Luminescent nanocrystals can also be used for non-contact optical temperature sensing.

[0166] Zr prepared in Example 9 0.985 Ti 0.005 Eu 0.01 O 1.995 Compared with Zr in Example 1 0.973 Ti 0.017 Eu 0.01 O 1.995 The XRD diffraction pattern is similar, and the main crystalline phase of the material is tetragonal zirconia with space group P42 / nmc. No further illustration is provided here. In Example 9, Zr... 0.985 Ti 0.005 Eu 0.01 O 1.995 The nanocrystal size, morphology, dispersibility and colloidal stability in water and ethanol are similar to those of Zr in Example 1. 0.973 Ti 0.017Eu 0.01 O 1.995 The results are similar, and no further illustrations are provided here. In Example 9, Zr... 0.985 Ti 0.005 Eu 0.01 O 1.995 The excitation and emission spectral distributions are similar to those of Zr in Example 1. 0.973 Ti 0.017 Eu 0.01 O 1.995 The results are similar, and no further illustrations are provided here. Zr in Example 9 0.985 Ti 0.005 Eu 0.01 O 1.995 Luminescent nanocrystals also include two types of Eu: Eu(I) and Eu(II). 3+ The ions, their respective excitation and emission spectral distributions, emission peaks, and fluorescence kinetics are similar to those of Zr in Example 1. 0.973 Ti 0.017 Eu 0.01 O 1.995 The results were similar. At low temperature, under 310nm ultraviolet light excitation, the Zr in Example 9... 0.985 Ti 0.005 Eu 0.01 O 1.995 The emission spectrum and its variation with temperature are similar to those of Zr in Example 1. 0.973 Ti 0.017 Eu 0.01 O 1.995 The results are similar, and no further illustrations are provided here. Zr in Example 9 0.985 Ti 0.005 Eu 0.01 O 1.995 Luminescent nanocrystals can also be used for non-contact optical temperature sensing.

[0167] Zr prepared in Example 10 0.9875 Ti 0.0025 Eu 0.01 O 1.995 Compared with Zr in Example 1 0.973 Ti 0.017 Eu 0.01 O 1.995 The XRD diffraction pattern is similar, and the main crystalline phase of the material is tetragonal zirconia with space group P42 / nmc. No further illustration is provided here. In Example 10, Zr... 0.9875 Ti 0.0025 Eu 0.01 O 1.995 The nanocrystal size, morphology, dispersibility and colloidal stability in water and ethanol are similar to those of Zr in Example 1.0.973 Ti 0.017 Eu 0.01 O 1.995 The results are similar, and no further illustrations are provided here. In Example 10, Zr... 0.9875 Ti 0.0025 Eu 0.01 O 1.995 The excitation and emission spectral distributions are similar to those of Zr in Example 1. 0.973 Ti 0.017 Eu 0.01 O 1.995 The results are similar, and no further illustrations are provided here. Zr in Example 10 0.9875 Ti 0.0025 Eu 0.01 O 1.995 Luminescent nanocrystals also include two types of Eu: Eu(I) and Eu(II). 3+ The ions, their respective excitation and emission spectral distributions, emission peaks, and fluorescence kinetics are similar to those of Zr in Example 1. 0.973 Ti 0.017 Eu 0.01 O 1.995 The results were similar. At low temperature, under 310nm ultraviolet light excitation, the Zr in Example 10... 0.9875 Ti 0.0025 Eu 0.01 O 1.995 The emission spectrum and its variation with temperature are similar to those of Zr in Example 1. 0.973 Ti 0.017 Eu 0.01 O 1.995 The results are similar, and no further illustrations are provided here. Zr in Example 10 0.9875 Ti 0.0025 Eu 0.01 O 1.995 Luminescent nanocrystals can also be used for non-contact optical temperature sensing.

[0168] Figure 17 The XRD patterns of the luminescent nanocrystalline materials in Example 1 and Comparative Example 1 are shown.

[0169] from Figure 17 It can be seen that in Comparative Example 1, Zr 0.99 Eu 0.01 O 1.995 Compared with Zr in Example 1 0.973 Ti 0.017 Eu 0.01 O 1.995The XRD diffraction pattern is somewhat different, with significantly broadened diffraction peaks, but the main crystalline phase of the material is still tetragonal zirconia, with space group P42 / nmc. The significant broadening of the diffraction peaks indicates that the grain size has further decreased and the crystallinity has deteriorated, indicating that the reaction temperature affects the growth of nanocrystals.

[0170] The luminescent nanocrystalline material Zr obtained in Comparative Example 1 0.99 Eu 0.01 O 1.995 The excitation and emission spectra were analyzed, and the results are as follows: Figures 18-19 As shown.

[0171] from Figure 18 It can be seen that, under room temperature and different ultraviolet light wavelengths of excitation, its emission spectrum is mainly Eu. 3+ of 5 D0- 7 F J It exhibits sharp-line characteristic emission, but its spectral energy distribution does not change with the excitation wavelength. (Similar to Zr in Example 1) 0.973 Ti 0.017 Eu 0.01 O 1.995 Compared to the results, its emission spectrum contains only one set of Eu(II) type Eu. 3+ Emission, Eu(I) type Eu 3+ None exist, and the emission peaks are all broadened. Among them, the emission lines of Eu(II) are located and assigned at 591.6 and 597.2 nm. 5 D0→ 7 F1); 614.0, 623.0, 631.2nm ( 5 D0→ 7 F2); 653.0nm 5 D0→ 7 F3); 703.0nm ( 5 D0→ 7 F4).

[0172] from Figure 19 It can be seen that when monitoring the emission peaks at 607 and 614 nm respectively, the measured Zr in Comparative Example 1... 0.99 Eu 0.01 O 1.995 The excitation spectrum contains only a broad and strong band (200-350 nm) and some spectral components originating from Eu. 3+ 4f-4f sharp line ( 5 D4← 7 F0, 5 G2← 7 F0, 5 L6← 7 F0, 5 D3← 7F0, 5 D2← 7 F0). Its broad spectral peak is located at ~265nm, originating from O 2- →Eu 3+ Charge transfer excitation (CT(O)) 2- →Eu 3+ No O was observed. 2- →Ti 4+ Charge transfer excitation. Spectroscopic analysis shows that the solvothermal reaction temperature affects Ti. 4+ Doping and Eu 3+ The occupancy of lattice sites has a significant impact. At low temperatures, Ti 4+ Eu cannot be effectively doped into the crystal lattice. 3+ It mainly occupies a symmetrical personality position.

[0173] 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 luminescent nanocrystalline material, characterized in that, Its general chemical formula is Zr 1-x-y Ti x Eu y O 2-0.5y ;where 0 < x ≤0.08, 0< y ≤0.05; The luminescent nanocrystalline material is a doped tetragonal zirconium oxide luminescent nanocrystalline material with space group P42 / nmc; wherein, Eu 3+ Simultaneously occupying two lattice sites of different symmetries: one is a high-symmetry site Eu(I) coordinated by eight oxygen ions, selecting a short excitation wavelength with an emission peak at 607 nm; the other is a low-symmetry site Eu(II) coordinated by seven oxygen ions, adjacent to oxygen vacancies, selecting a long excitation wavelength with an emission peak at 614 nm. The excitation band peaks, emission band peaks, and fluorescence lifetimes of the high-symmetry site Eu(I) and the low-symmetry site Eu(II) differ significantly and are easily distinguishable. In the lattice, the doped ions are not randomly distributed; Ti... 4+ Preferentially associated with the low-symmetry character site Eu(II); utilizing O 2 →Ti 4+ Charge transfer excitation to Eu 3+ The unique energy transfer between ions enables Eu 3+ This results in efficient light emission and an expansion of the effective excitation wavelength range.

2. The luminescent nanocrystalline material as described in claim 1, characterized in that, 0.0025≤ x ≤0.057，0.004≤ y ≤0.04。 3. The luminescent nanocrystalline material as described in claim 2, characterized in that, Its chemical formula is Zr 0.973 Ti 0.017 Eu 0.01 O 1.995 Zr 0.979 Ti 0.017 Eu 0.004 O 1.998 Zr 0.963 Ti 0.017 Eu 0.02 O 1.99 Zr 0.943 Ti 0.017 Eu 0.04 O 1.98 Zr 0.963 Ti 0.027 Eu 0.01 O 1.995 Zr 0.933 Ti 0.057 Eu 0.01 O 1.995 Zr 0.985 Ti 0.005 Eu 0.01 O 1.995 Zr 0.9875 Ti 0.0025 Eu 0.01 O 1.995 Any one of them.

4. A method for preparing a luminescent nanocrystalline material as described in any one of claims 1 to 3, characterized in that, Includes the following steps: The Zr source was added to the first solvent and stirred to obtain the first solution; Add the Eu source to the first solution and stir to obtain the second solution; The Ti source was added to the second solution and stirred to obtain the third solution; Add acetic acid and water to the third solution, stir, and carry out a hydrolysis reaction to obtain the fourth solution; The fourth solution was placed in a reaction vessel for a solvothermal reaction, followed by solid-liquid separation, washing, and drying to obtain luminescent nanocrystalline materials.

5. The method for preparing the luminescent nanocrystalline material as described in claim 4, characterized in that, In the step of placing the fourth solution in a reaction vessel and carrying out a solvothermal reaction, the reaction temperature is 240~280 ℃ and the time is 8~12 h.

6. The method for preparing the luminescent nanocrystalline material as described in claim 4, characterized in that, The first solvent includes at least one of n-propanol, isopropanol, and n-butanol.

7. The method for preparing the luminescent nanocrystalline material as described in claim 4, characterized in that, The Zr source is an alkoxide liquid containing Zr, and the Zr-containing alkoxide liquid includes at least one of the following: a zirconium n-propoxide solution in n-propanol, a zirconium isopropoxide solution, and a zirconium n-butoxide solution in n-butanol. And / or, the Eu source is a solution containing Eu, and the solution containing Eu includes at least one of europium-containing n-propanol solution, europium-containing isopropanol solution, and europium-containing n-butanol solution; And / or, the Ti source is an alkoxide liquid containing Ti, wherein the Ti-containing alkoxide liquid includes at least one of titanium n-propoxide, isopropyl titanate, a n-propanol solution of n-butyl titanate, an isopropanol solution of isopropyl titanate, and a n-butanol solution of n-butyl titanate.

8. The method for preparing the luminescent nanocrystalline material as described in claim 7, characterized in that, The method for preparing the solution containing Eu element is as follows: dissolve the solid compound containing Eu element in a second solvent to obtain the solution containing Eu element, wherein the second solvent includes at least one of n-propanol, isopropanol and n-butanol. The Eu ion concentration in the solution containing Eu is 0.01~0.5 mol / L; The solid compound containing Eu includes at least one of europium nitrate, europium chloride, europium nitrate containing water of crystallization, and europium chloride containing water of crystallization.

9. The method for preparing the luminescent nanocrystalline material as described in claim 4, characterized in that, The volume ratio of the first solvent, acetic acid, and water is (50~70):(0.1~0.3):(0.3~0.5); During the process of obtaining the first, second, third, and fourth solutions by stirring, the stirring time is 5 to 15 minutes.

10. The application of a luminescent nanocrystalline material as described in any one of claims 1 to 3 or a luminescent nanocrystalline material prepared by any one of claims 4 to 9 in non-contact temperature detection, fluorescence bioimaging, information encoding, fluorescent ink, fluorescence sensing, electronic printing, and the fabrication of light-emitting devices.

Images