A Mn for plant lighting 4+ Activated red fluorescent material, preparation and use thereof

Abstract

The application belongs to the field of luminescent materials, and discloses a Mn 4+ activated red fluorescent material for plant lighting, a preparation method and application thereof. 18 W 8‑ x O 53 :xMn 4+ , 0.001≤x≤0.009. The emission spectrum of the fluorescent material is a characteristic emission peak of transition metal ions Mn 4+ , and under excitation in the near-ultraviolet to blue light region, red light or far-red light of 660-825 nm can be emitted, which matches the absorption wavelength of plant photosensitive pigments, and can be applied to the preparation of an LED light source for indoor plant lighting. The preparation method is very simple and easy to implement, raw materials are simple and easy to obtain, and the preparation method is environmentally friendly and non-polluting.

Description

Technical Field

[0001] This invention belongs to the field of luminescent materials, and specifically relates to a Mn alloy for plant lighting. 4+ Activated red fluorescent materials, their preparation methods, and applications. Background Technology

[0002] Light plays a crucial role in the germination, growth, flowering, and fruiting processes of cultivated plants. However, under natural conditions, the light required for plant growth and development is greatly influenced by the environment, thus necessitating the invention of a light source suitable for plant illumination. It is worth noting that phytochrome (P) is a promising candidate for this purpose. r and P fr Phytochromes participate in numerous plant physiological processes (such as seed germination, seedling development, photosynthesis, and flowering). Phytochromes exist in two forms: one is the red-light-absorbing form (P...). r One type typically absorbs red light around 660nm; the other type is far-red light absorbing (P...). fr Light-emitting diodes (LEDs) typically absorb far-red light around 730nm; these two different forms of light promote plant growth through light absorption. LEDs have become the first choice for plant lighting due to their advantages such as small size, long lifespan, low energy consumption, and environmental friendliness.

[0003] transition metal Mn 4+ Ions have special 3d 3 Electronic configuration, in part of Mn 4+ In activated fluorescent materials, Mn 4+ Being in a strong crystal field environment, this makes Mn 4+ Spin-forbidden 2 E→ 4 The A2 transition typically emits red or deep red light, which matches the absorption spectrum of the phytochrome.

[0004] At present, Mn has been commercially available 4+ Activated red fluorescent materials are mostly fluoride fluorescent materials, such as K2SiF6:Mn 4 + However, fluoride fluorescent materials have drawbacks such as poor chemical stability, complex synthesis process, and environmentally unfriendly synthesis process. Summary of the Invention

[0005] In order to overcome the shortcomings and deficiencies of the prior art, the primary objective of this invention is to provide a novel Mn for plant lighting. 4+ The activated red fluorescent material emits light at wavelengths of 660-825 nm.

[0006] Another object of the present invention is to provide the above-mentioned novel Mn for plant lighting. 4+A method for preparing activated red fluorescent materials.

[0007] Another object of the present invention is to provide the above-mentioned Mn for plant lighting. 4+ Applications of activated red fluorescent materials.

[0008] The objective of this invention is achieved through the following solution:

[0009] A novel Mn for plant lighting 4+ The activated red fluorescent material has the chemical formula: Ca2La 18 W 8-x O 53 :xMn 4 + ,0.001≤x≤0.009.

[0010] A type of Mn for plant lighting described above 4+ The method for preparing activated red fluorescent materials is characterized by comprising the following steps:

[0011] According to Ca2La 18 W 8-x O 53 :xMn 4+ The stoichiometric ratio of raw materials containing Ca, La, W, and Mn compounds is 0.001≤x≤0.009. These compounds are then ground, mixed uniformly, and sintered at high temperature to obtain Mn for plant lighting. 4+ Activated red fluorescent material.

[0012] The Ca-containing compound is preferably CaCO3 or CaO;

[0013] The La-containing compound is preferably La2O3;

[0014] The W-containing compound is preferably WO3;

[0015] The Mn-containing compound is preferably MnCO3;

[0016] The grinding process is preferably carried out by adding anhydrous ethanol. After the ethanol has completely evaporated, the ground mixture is transferred to a muffle furnace for high-temperature sintering.

[0017] The high-temperature sintering refers to heating to 1250-1350℃ at a heating rate of 5℃ / min in air atmosphere and holding the temperature for 5 hours, preferably at 1350℃ for 5-8 hours.

[0018] After high-temperature sintering, the product was removed from the muffle furnace and cooled to room temperature. It was then ground into powder again to obtain Mn for plant lighting. 4+ Activated red fluorescent material.

[0019] The above-mentioned Mn for plant lighting 4+ Application of activated red fluorescent materials in plant lighting.

[0020] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0021] Mn for plant lighting of the present invention 4+ The activated red fluorescent material is an oxide with stable physicochemical properties. The light it emits can match the light absorbed by the plant's phytochromes, and it has high absorption efficiency for ultraviolet and visible light. It can be well matched with the ultraviolet and blue light emitted by the LED chip on the plant grow light, and can be better applied to plant lighting. Attached Figure Description

[0022] Figure 1 This is the XRD pattern of the fluorescent material prepared in Example 2 of this invention.

[0023] Figure 2 This is the excitation spectrum of the fluorescent material prepared in Example 2 of this invention.

[0024] Figure 3 This is the emission spectrum of the fluorescent material prepared in Example 2 of this invention.

[0025] Figure 4 This is a comparison of the emission spectrum of the fluorescent material prepared in Example 2 of the present invention with the absorption spectrum of plant phytochromes (Pr and Pfr). Detailed Implementation

[0026] The present invention will be further described in detail below with reference to embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto. Unless otherwise specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments used, unless otherwise specified, are all commercially available conventional products.

[0027] In this embodiment, an Edinburgh FLS1000 spectrometer equipped with a PMT-900 photomultiplier tube with a cooled housing was used to record the UV-Vis excitation and emission spectra of the samples. A 450W xenon lamp was used as the excitation source for steady-state excitation and emission spectra.

[0028] Example 1

[0029] Mn for plant lighting 4+ The activated red fluorescent material has the chemical formula Ca2La. 18 W 7.999 O 53 0.001Mn 4+ .

[0030] The Mn used for plant lighting 4+The preparation method of activated red fluorescent material includes the following steps:

[0031] Step 1, based on the general chemical formula Ca2La 18 W 7.999 O 53 0.001Mn 4+ The stoichiometric ratios of each element in the raw materials were as follows: calcium oxide (99.99%), lanthanum oxide (99.99%), tungsten oxide (99.99%), and manganese carbonate (99.99%).

[0032] Step 2: Place the weighed raw materials into an agate mortar, add anhydrous ethanol, and grind and mix evenly. After the ethanol has completely evaporated, transfer the ground mixture into an alumina crucible.

[0033] Step 3: Place the alumina crucible in a muffle furnace for high-temperature sintering, then remove it after the muffle furnace has cooled to room temperature. Grind the obtained product into powder again to obtain Mn for plant lighting. 4+ Activated red fluorescent material.

[0034] The high-temperature sintering atmosphere is air sintering. The high-temperature sintering conditions are 1350℃ for 5 hours and a heating rate of 5℃ / min.

[0035] Example 2

[0036] Mn for plant lighting 4+ The activated red fluorescent material has the chemical formula Ca2La. 18 W 7.995 O 53 0.005Mn 4+ .

[0037] The Mn used for plant lighting 4+ The preparation method of activated red fluorescent material includes the following steps:

[0038] Step 1, based on the general chemical formula Ca2La 18 W 7.995 O 53 0.005Mn 4+ The stoichiometric ratios of each element in the raw materials were as follows: calcium oxide (99.99%), lanthanum oxide (99.99%), tungsten oxide (99.99%), and manganese carbonate (99.99%).

[0039] Step 2: Place the weighed raw materials into an agate mortar, add anhydrous ethanol, and grind and mix evenly. After the ethanol has completely evaporated, transfer the ground mixture into an alumina crucible.

[0040] Step 3: Place the alumina crucible in a muffle furnace for high-temperature sintering, then remove it after the muffle furnace has cooled to room temperature. Grind the obtained product into powder again to obtain Mn for plant lighting. 4+ Activated red fluorescent material.

[0041] The high-temperature sintering atmosphere is air sintering. The high-temperature sintering conditions are 1350℃ for 5 hours and a heating rate of 5℃ / min.

[0042] Example 3

[0043] Mn for plant lighting 4+ The activated red fluorescent material has the chemical formula Ca2La. 18 W 7.991 O 53 0.009Mn 4+ .

[0044] The Mn used for plant lighting 4+ The preparation method of activated red fluorescent material includes the following steps:

[0045] Step 1, based on the general chemical formula Ca2La 18 W 7.991 O 53 0.009Mn 4+ The stoichiometric ratios of the elements in the raw materials are as follows: calcium oxide (99.99%), lanthanum oxide (99.99%), tungsten oxide (99.99%), and manganese carbonate (99.99%).

[0046] Step 2: Place the weighed raw materials into an agate mortar, add anhydrous ethanol, and grind and mix evenly. After the ethanol has completely evaporated, transfer the ground mixture into an alumina crucible.

[0047] Step 3: Place the alumina crucible in a muffle furnace for high-temperature sintering, then remove it after the muffle furnace has cooled to room temperature. Grind the obtained product into powder again to obtain Mn for plant lighting. 4+ Activated red fluorescent material.

[0048] The high-temperature sintering atmosphere is air sintering. The high-temperature sintering conditions are 1350℃ for 5 hours and a heating rate of 5℃ / min.

[0049] Figure 1 The Mn used for plant lighting prepared in Example 2 4+ The XRD pattern of the activated red fluorescent material shows that the sample diffraction peaks are related to Ca2La. 18 W8O 53The sample is in perfect agreement with the standard card PDF#00-049-0966, indicating that the Mn-substituted W has completely entered the crystal lattice and there are no obvious impurity peaks, which indicates that the phase purity of the prepared sample is high.

[0050] Figure 2 The fluorescent material Ca2La prepared in Example 2 18 W 7.995 O 53 0.005Mn 4+ The excitation spectrum indicates that it can be effectively excited by chips that emit blue or ultraviolet light in plant grow lights.

[0051] Figure 3 The fluorescent material Ca2La prepared in Example 2 18 W 7.995 O 53 0.005Mn 4+ The emission spectrum shows an emission peak at 721 nm and a full width at half maximum (FWHM) of 45 nm.

[0052] Figure 4 The fluorescent material Ca2La prepared in Example 2 18 W 7.995 O 53 0.005Mn 4+ The comparison diagram of the effective overlap between the emission spectrum of the fluorescent material and the absorption spectra of the plant's luminescent pigments (Pr and Pfr) shows that the light emitted by the fluorescent material can be effectively absorbed by the plant's luminescent pigments, thereby promoting plant growth.

[0053] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A type of Mn for plant lighting 4+ Activated red fluorescent material, characterized in that The chemical formula is: Ca2La 18 W 8-x O 53 :xMn 4+ ,0.001≤x≤0.

009.

2. A Mn-based plant lighting device according to claim 1 4+ The method for preparing activated red fluorescent materials is characterized by Includes the following steps: According to Ca2La 18 W 8-x O 53 : xMn 4+ The raw materials, containing Ca, La, W, and Mn compounds, were weighed according to their stoichiometric ratio, ground and mixed evenly, and then sintered at high temperature to obtain Mn for plant lighting. 4+ Activated red fluorescent material.

3. The Mn for plant lighting according to claim 2 4+ The method for preparing activated red fluorescent materials is characterized by: The Ca-containing compound is CaO or CaCO3.

4. The Mn for plant lighting according to claim 2 4+ The method for preparing activated red fluorescent materials is characterized by: The La-containing compound is La2O3.

5. The Mn for plant lighting according to claim 2 4+ The method for preparing activated red fluorescent materials is characterized by: The W-containing compound is WO3.

6. The Mn for plant lighting according to claim 2 4+ The method for preparing activated red fluorescent materials is characterized by: The Mn-containing compound is MnCO3.

7. The Mn for plant lighting according to claim 2 4+ The method for preparing activated red fluorescent materials is characterized by: The grinding process involves adding anhydrous ethanol and grinding the mixture. After the ethanol has completely evaporated, the ground mixture is transferred to a muffle furnace for high-temperature sintering.

8. The Mn for plant lighting according to claim 2 4+ The method for preparing activated red fluorescent materials is characterized by: The high-temperature sintering refers to heating to 1250-1350℃ and holding the temperature for 5-8 hours in an air atmosphere.

9. The Mn for plant lighting as described in claim 1 4+ Application of activated red fluorescent materials in plant lighting.

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