CN115261018A - A kind of red inorganic phosphor capable of promoting the growth of greenhouse plants and preparation method thereof - Google Patents

Abstract

The invention discloses a red inorganic fluorescent powder capable of promoting the growth of greenhouse plants and a preparation method thereof, belonging to the technical field of luminescent materials. The general chemical formula of the fluorescent powder is CaAl _12-x-y O ₁₉ : xMn ⁴⁺ , yGd ³⁺ , wherein, 0<x<0.5, 0<y<0.5, and the preparation method of the phosphor is: firstly calculate and weigh each raw material according to the general chemical formula, mix the weighed raw materials, and then put it in an air atmosphere for 1300~ calcined at 1600 ℃, kept for 2 to 10 hours, and it can be obtained after cooling, grinding and screening in the furnace. The invention uses aluminate as a matrix, and prepares aluminate-based manganese-doped red fluorescent powder suitable for plant growth by doping activated ions Mn ⁴⁺ . The emission wavelength is 630nm-680nm, and the main emission peak is located at 650nm, which solves the problems of poor luminescence performance of the existing organic red phosphors, serious light attenuation, unstable performance and easy decomposition, and the high price of traditional plant growth LED lamps. .

Description

A kind of red inorganic fluorescent powder that can promote the growth of greenhouse plants and its preparation method

technical field

The invention belongs to the technical field of luminescent materials and is suitable for adding 1% to 10% red fluorescent powder to the field of greenhouse covering film for plant growth to promote the growth of crops, in particular to a red inorganic fluorescent powder capable of promoting the growth of greenhouse plants and its Preparation.

Background technique

Light is one of the most important environmental factors for plant growth. Due to the lower solar altitude angle in winter, and the influence of continuous cloudy days, smog and other weather conditions, the problem of insufficient light is common in the growth of most plants. Light quality has an important influence on the growth and development of plants, yield formation and fruit quality improvement. The wavelength of sunlight reaching the earth is 290-3000nm, but only a small proportion can be absorbed and utilized by plants, mainly concentrated in the visible light region 420-500nm blue light and 580-700nm red light.

In the field of agricultural technology, crop mulch films are widely used because they help the growth of crops, and have the characteristics of moisturizing and heat preservation. The mulch film currently used has great limitations. Since most crops absorb red light more obviously, but there is less red light in sunlight, therefore, the crops have a low utilization rate of sunlight.

At present, in order to promote the growth of economic crops on the market, traditional plant growth LED lights are mainly used, which mainly emit blue light and red light required for plant growth. Problems with plant growth LED lights: In addition to high-cost nitride phosphors and high-cost LED devices, power supply and buildings or greenhouses are required, which makes the cost of LED plant growth lights very high. Although LED plant growth lights can increase crop yields, the cost of general crops is low, and it is difficult to widely use LED plant growth lights.

At present, some scientific research institutions on the market have tried to use organic red light-emitting materials (such as vinyl of heterocyclic compounds) to make films for the growth of greenhouse plants. Problems with the red organic film for plant growth: Under sunlight, the red organic material is unstable and easy to decompose, the emitted red light will decay within 3 months, and the film will also turn yellow and decompose within 3 months.

The light conversion film is a functional agricultural film that improves the light utilization efficiency of plants by adding different light conversion agents to improve the light transmittance and convert the light wavelength. The use of light-converting film can convert part of the ultraviolet light into blue-violet light and red-orange light that can be used by plants for photosynthesis, and convert the green light that accounts for a large part of visible light but cannot be used by plants into red-orange light, thereby improving the photosynthesis of plants. The effect is to promote the increase of crop yield and the improvement of quality. Light conversion film is widely used as an effective method to deal with the insufficient utilization of sunlight. However, in actual production, the selection and application strategies of light conversion films are still unclear, and there are few studies on the efficiency of light conversion films. There are still many problems in the scale and standardized application of light conversion films.

Contents of the invention

The object of the present invention is to provide a red inorganic fluorescent powder capable of promoting the growth of greenhouse plants and its preparation method, so as to solve the problems raised in the above-mentioned background technology.

In order to achieve the above object, the technical scheme adopted in the present invention is:

A red inorganic fluorescent powder that can promote the growth of greenhouse plants. The fluorescent powder has the following general chemical formula: CaAl _12-xy O ₁₉ : xMn ⁴⁺ , yGd ³⁺ , where 0<x<0.5, 0<y< 0.5, the matrix of the phosphor is aluminate, and the active ion of the phosphor is Mn ⁴⁺ .

The fluorescent powder has a maximum emission peak in the region of 630-680nm.

The preparation method of described fluorescent powder specifically comprises the following steps:

1) Calculate the mass of calcium-containing solid compound, aluminum-containing solid compound, manganese-containing solid compound, and gadolinium-containing solid compound according to the molar ratio of each element in the chemical formula of the red inorganic phosphor, and according to the percentage of the co-solvent boron-containing compound in the total mass of raw materials The mass percentage is used to calculate the mass of the co-solvent boron-containing compound, and after accurate weighing, mix the above-mentioned raw materials with a super mixer for 1 hour;

2) Put the mixed raw materials in step 1) into a 500mL high-alumina crucible, calcinate at 1300-1600°C in an air atmosphere, keep the temperature for 2-10 hours, and cool to room temperature with the furnace;

3) The raw powder calcined in step 2) is pulverized, ball milled, wet sieved, washed with water, dried, and dry sieved to obtain a uniform red inorganic fluorescent powder product.

The calcium-containing solid compound is calcium oxide or calcium oxysalt.

The aluminum-containing solid compound is aluminum oxide or aluminum oxo acid salt.

The manganese-containing solid compound is manganese dioxide or manganese oxysalt.

The gadolinium-containing solid compound is gadolinium oxide or gadolinium oxysalt.

The co-solvent boron-containing compound is boric acid, and the mass percentage of the co-solvent boric acid in the total mass of raw materials is 1%-6%.

In summary, owing to adopting above-mentioned technical scheme, the beneficial effect of the present invention is:

1) The present invention adopts a high-temperature solid-phase method for the preparation of red inorganic fluorescent powder, the process equipment requirements are simple, the experimental conditions are easy to achieve, the production cycle is short, the production cost is low, green and environmentally friendly, and the reproducibility is good, which is suitable for large-scale industrial production;

2) The aluminate-based manganese-doped red phosphor suitable for plant growth prepared by this method uses aluminate as a matrix and is doped with active ions Mn ⁴⁺ to prepare aluminate-based manganese-doped red phosphor suitable for plant growth. Manganese red phosphor is an inorganic compound with stable performance and is not easy to decompose. The excitation wavelength is 250nm-500nm, the emission wavelength is 630nm-680nm, and the main emission peak is located at 650nm. Attenuation, unstable performance, easy to decompose, and the high price of traditional plant growth LED lamps can effectively prolong the service life of the light conversion film, which provides a theoretical basis for the research and development of light conversion film technology;

3) The present invention can convert more ultraviolet light in sunlight into red light, can promote plant growth, increase the absorption of key elements in plants, and then achieve the effect of increasing production and quality, and has good economic benefits and broad market applications prospect.

Description of drawings

FIG. 1 is a comparison chart of the emission spectra of phosphor powder 1, phosphor powder 2, phosphor powder 3, and phosphor powder 4 in the embodiment.

Fig. 2 is a comparison chart of OD values in the growth process of Example Chlorella 1, Chlorella 2, Chlorella 3, Chlorella 4 and Comparative Example Chlorella 5.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments It is a part of embodiments of the present invention, but not all embodiments. The components of the embodiments of the invention generally described and illustrated in the figures herein may be arranged and designed in a variety of different configurations.

Accordingly, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

The present invention provides a kind of red fluorescent powder suitable for plant growth prepared by doping the activated ion Mn ⁴⁺ with aluminate as the matrix. The general chemical composition formula of the fluorescent powder is: CaAl _12-xy O ₁₉ : xMn ⁴⁺ , yGd ³⁺ , where 0<x<0.5, 0<y<0.5.

The excitation wavelength of the fluorescent powder is 250nm-500nm, the emission wavelength is 630nm-680nm, and the main emission peak is located at 650nm.

The preparation method of described fluorescent powder specifically comprises the following steps:

1) Calculate the mass of calcium-containing solid compound, aluminum-containing solid compound, manganese-containing solid compound, and gadolinium-containing solid compound according to the molar ratio of each element in the chemical formula of the red inorganic phosphor, and according to the percentage of the co-solvent boron-containing compound in the total mass of raw materials The mass percentage is 1% to 6% to calculate the mass of co-solvent boron-containing compounds;

The calcium-containing solid compound is calcium oxide or an oxysalt of calcium;

The aluminum-containing solid compound is aluminum oxide or an oxysalt of aluminum;

The manganese-containing solid compound is manganese dioxide or manganese oxysalt;

The gadolinium-containing solid compound is gadolinium oxide or an oxo-salt of gadolinium;

The boron-containing compound of the co-solvent is boric acid;

After accurate weighing, mix the above raw materials with a super mixer for 1 hour;

2) Put the mixed raw materials in step 1) into a 500mL high-alumina crucible, calcinate at 1300-1600°C in an air atmosphere, keep the temperature for 2-10 hours, and cool to room temperature with the furnace;

3) The raw powder calcined in step 2) is pulverized, ball milled, wet sieved, washed with water, dried, and dry sieved to obtain a uniform red inorganic fluorescent powder product.

Example 1

According to the chemical formula CaAl _11.65 O ₁₉ : 0.25Mn ⁴⁺ , 0.1Gd ³⁺ weigh 10.009g of calcium carbonate, 59.392g of alumina, 2.174g of manganese dioxide, 1.812g of gadolinium oxide, and 2.202g of boric acid, and mix them with a super mixer 1h, put it into a 500mL high-alumina crucible, calcinate at 1400°C in air atmosphere, keep warm for 6 hours, cool to room temperature with the furnace, and get a uniform red color after crushing, ball milling, wet sieving, water washing, drying, and dry sieving Inorganic phosphor finished product 1.

Mix the red inorganic phosphor finished product 1 and PDMS glue evenly at a mass ratio of 1:9, pour it into a glass mold to make a 30*30 light conversion film 1, apply it to the growth of Chlorella 1 and observe its growth process.

Example 2

Weigh 10.009g calcium carbonate, 59.902g alumina, 1.304g manganese dioxide, 1.812g gadolinium oxide, 2.191g boric acid according to ⁺ chemical formula CaAl _11.75 O ₁₉ : 0.15Mn ⁴⁺ , 0.1Gd ³ and mix them with a super mixer 1h, put it into a 500mL high-alumina crucible, calcinate at 1400°C in air atmosphere, keep warm for 6 hours, cool to room temperature with the furnace, and get a uniform red color after crushing, ball milling, wet sieving, water washing, drying, and dry sieving Inorganic phosphor finished product 2.

Mix the red inorganic phosphor finished product 2 and PDMS glue evenly at a mass ratio of 1:9, pour it into a glass mold to make a 30*30 light conversion film 2, apply it to the growth of Chlorella 2 and observe its growth process.

Example 3

According to the chemical formula CaAl _11.55 O ₁₉ : 0.35Mn ⁴⁺ , 0.1Gd ³⁺ weigh 10.009g of calcium carbonate, 58.882g of alumina, 3.043g of manganese dioxide, 1.812g of gadolinium oxide, and 2.212g of boric acid, and mix them with a super mixer 1h, put it into a 500mL high-alumina crucible, calcinate at 1400°C in air atmosphere, keep warm for 6 hours, cool to room temperature with the furnace, and get a uniform red color after crushing, ball milling, wet sieving, water washing, drying, and dry sieving Inorganic phosphor finished product 3.

Mix the red inorganic phosphor finished product 3 and PDMS glue evenly at a mass ratio of 1:9, pour it into a glass mold to make a 30*30 light conversion film 3, apply it to the growth of Chlorella 3 and observe its growth process.

Example 4

According to the chemical formula CaAl _11.75 O ₁₉ : 0.25Mn ⁴⁺ , weigh 10.009g of calcium carbonate, 59.902g of alumina, 2.174g of manganese dioxide, and 2.163g of boric acid, mix them with a super mixer for 1 hour, and put them into a 500mL high-alumina crucible Calcined at 1400°C in an air atmosphere, kept at 6 hours, cooled down to room temperature with the furnace, crushed, ball milled, wet sieved, washed with water, dried, and dry sieved to obtain a uniform red inorganic phosphor finished product 4.

Mix the red inorganic phosphor finished product 4 and PDMS glue evenly at a mass ratio of 1:9, pour it into a glass mold to make a 30*30 light conversion film 4, apply it to the growth of Chlorella 4 and observe its growth process.

Comparative example 5

Take the chlorella 5 without using the light conversion film as a comparison sample, and observe the growth process of the chlorella 5.

Conclusion: as shown in Figure 1, phosphor powder 1, 2, 3, 4 prepared in embodiment 1, 2, 3, 4 is carried out emission spectrum contrast, from Fig. 1 we can see that embodiment 1 and embodiment The luminous intensity of 4 is stronger than that of Example 2 and Example 3, indicating that the doping amount of Mn ⁴⁺ has a greater influence on the luminous intensity.

As shown in Figure 2, the light-converting films prepared in Examples 1, 2, 3, and 4 were used for the growth of Chlorella 1, 2, 3, and 4, respectively, and compared with Chlorella 5 that did not use the light-converting film , from Figure 2 we can see that the growth of Chlorella 1, 2, 3, and 4 has a larger OD value than that of Chlorella 5, indicating that the light conversion film can promote the growth of Chlorella. At the same time, the growth OD values of Chlorella 1 and Chlorella 4 are not much different, and both are larger than the growth OD values of Chlorella 2 and Chlorella 3, so it shows that the addition of Gd ³⁺ can increase the luminescence of the light conversion film Strength, thereby promoting the growth of chlorella.

Claims (8)

1. The red inorganic fluorescent powder capable of promoting growth of greenhouse plants is characterized by having the following chemical general formula: caAl_12-x-yO₁₉：xMn⁴⁺，yGd³⁺Wherein x is more than 0 and less than 0.5, y is more than 0 and less than 0.5, the matrix of the fluorescent powder is aluminate, and the active ion of the fluorescent powder is Mn⁴⁺。

2. The red inorganic fluorescent powder capable of promoting growth of greenhouse plants as claimed in claim 1, wherein: the fluorescent powder has a maximum emission peak in a 630-680 nm region.

3. A method for preparing the red inorganic phosphor according to claim 1, wherein: the method specifically comprises the following steps:

1) Respectively calculating the mass of a calcium-containing solid compound, an aluminum-containing solid compound, a manganese-containing solid compound and a gadolinium-containing solid compound according to the molar ratio of each element in the chemical formula of the red inorganic fluorescent powder, calculating the mass of a cosolvent boron-containing compound according to the mass percentage of the cosolvent boron-containing compound in the total mass of the raw materials, accurately weighing, and mixing the raw materials for 1 hour by using a super mixer;

2) Putting the mixed raw materials in the step 1) into a 500mL high-alumina crucible, calcining at 1300-1600 ℃ in an air atmosphere, preserving heat for 2-10 hours, and cooling to room temperature along with the furnace;

3) And (3) crushing, ball-milling, screening by a wet sieve, washing by water, drying and screening by a dry sieve on the calcined raw powder block in the step 2) to obtain a uniform red inorganic fluorescent powder finished product.

4. The method for preparing the red inorganic phosphor according to claim 3, wherein: the calcium-containing solid compound is calcium oxide or calcium oxysalt.

5. The method for preparing the red inorganic phosphor according to claim 3, wherein: the aluminum-containing solid compound is aluminum oxide or an oxyacid salt of aluminum.

6. The method for preparing the red inorganic phosphor according to claim 3, wherein: the manganese-containing solid compound is manganese dioxide or manganese oxysalt.

7. The method for preparing the red inorganic phosphor according to claim 3, wherein: the gadolinium-containing solid compound is gadolinium oxide or gadolinium oxysalt.

8. The method for preparing the red inorganic phosphor according to claim 3, wherein: the cosolvent boron-containing compound is boric acid, and the cosolvent boric acid accounts for 1-6% of the total mass of the raw materials.

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