Graphene sol coupled amino acid trace element composite material as well as preparation method and application thereof

Abstract

The invention provides a graphene sol coupled amino acid trace element composite material as well as a preparation method and application thereof. The composite material comprises the following components in parts by weight: 30-100 parts of graphene oxide sol, 10-90 parts of amino acid, 15-50 parts of a nitrogen element, 5-30 parts of a phosphorus element, 5-30 parts of a potassium element and 5-40 parts of medium trace elements. The composite material can improve the utilization rate of nutrient elements, provide comprehensive and balanced nutrition for crop growth, improve the soil structure, and improve the quality and yield of crops.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of agricultural fertilizers, in particular to a graphene sol coupled amino acid trace element composite material, a preparation method thereof and an application thereof. BACKGROUND

[0002] The sustainable development of agriculture in China requires fertilizers to be "highly efficient, environmentally friendly, and multi-functional". Traditional fertilizers, especially trace element fertilizers, have low nutrient utilization rate (such as less than 10% for iron and zinc), are prone to cause soil acidification / salinity, and cause non-point source pollution, which cannot meet the needs of modern precision agriculture. Under this background, amino acid trace element chelate fertilizer has become one of the core directions to replace traditional inorganic trace element fertilizer due to its characteristics of "stable chelation, high biological efficiency, and low environmental risk". The amino acid molecule contains amino groups (-NH2) and carboxyl groups (-COOH), which can form a ring chelate with Fe²⁺, Zn²⁺, Mn²⁺, Cu²⁺ and other trace elements through coordination bond, significantly reducing the risk of being fixed in soil by phosphates, carbonates, etc., and improving root absorption efficiency. Compared with inorganic trace element fertilizer, amino acid chelate fertilizer has the following advantages: (1) alleviating the "antagonistic effect" of trace elements and reducing the mutual inhibition with other nutrients (such as phosphorus); (2) reducing physiological diseases caused by nutrient deficiency in crops; (3) some amino acids can directly participate in crop metabolism, having both nutritional and physiological regulation functions. However, there are still significant technical bottlenecks in the preparation and application of existing amino acid trace element chelate fertilizer, which restricts its large-scale promotion. Its function is single, most products lack synergistic function, do not integrate other agricultural functions, lack of absorption-promoting substances, and cannot further improve the active absorption efficiency of chelates by roots; environmental friendliness is not considered, and some preparation processes need to add chemical additives (such as EDTA as auxiliary complexing agent), which may introduce secondary pollution.

[0003] Therefore, it is of great practical significance to develop an amino acid trace element chelate fertilizer preparation technology with high chelation efficiency, adjustable release, multi-function and green low carbon. SUMMARY

[0004] The purpose of the present application is to provide a graphene sol coupled amino acid trace element composite material, which can improve the utilization rate of nutrient elements, provide comprehensive and balanced nutrition for crop growth, improve soil structure, and improve the quality and yield of crops.

[0005] In order to solve the above technical problems, the present application provides the following technical solutions: A graphene sol-coupled amino acid trace element composite material, comprising the following components by weight: 30-100 parts of graphene oxide sol, 10-90 parts of amino acid (one of glycine, glutamic acid or histidine), 15-50 parts of nitrogen (urea), 5-30 parts of phosphorus (potassium dihydrogen phosphate), 5-30 parts of potassium (potassium sulfate), and 5-40 parts of trace elements (Ca(NO3)2·4H2O, Mg(NO3)2·6H2O, CuSO4·5H2O, ZnSO4·7H2O, Mn(NO3)2·4H2O, FeSO4·7H2O, (NH4)2B4O7, (NH4)2MoO4).

[0006] According to an embodiment of the present invention, the graphene oxide sol comprises 60-90 parts, amino acids 10-40 parts, nitrogen 15-20 parts (urea), phosphorus 10-20 parts (potassium dihydrogen phosphate), potassium 10-20 parts (potassium sulfate), and / or trace elements 10-25 parts.

[0007] According to an embodiment of the present invention, the solid content of the graphene oxide sol is 0.3~1.0%, for example 0.5~0.8%.

[0008] According to one embodiment of the present invention, the composite material comprises the following components by weight: 90 parts graphene oxide sol, 20 parts amino acids, 15 parts nitrogen, 10 parts phosphorus, 10 parts potassium, 9 parts medium-weight elements, and 5 parts trace elements.

[0009] According to one embodiment of the present invention, the composite material comprises the following components by weight: 90 parts graphene oxide sol, 20 parts amino acids, 15 parts nitrogen, 10 parts phosphorus, 10 parts potassium, 9 parts medium-weight elements, and 9 parts trace elements.

[0010] According to one embodiment of the present invention, the composite material comprises the following components by weight: 90 parts graphene oxide sol, 20 parts amino acids, 15 parts nitrogen, 10 parts phosphorus, 10 parts potassium, 9 parts medium-weight elements, and 13 parts trace elements.

[0011] According to an embodiment of the present invention, the graphene oxide sol is prepared by the following method: The graphene oxide sol is prepared using a high-frequency AC pulse method according to patent document CN106587018B. For example, firstly, anode and cathode plates of high-purity graphite with dimensions of 600mm × 300mm × 80mm are placed in an electrolytic oxidation tank, with a distance of 70mm between the anode and cathode plates; then, 0.09% sulfuric acid electrolyte is poured into the tank, the power is turned on, and electrolytic oxidation is performed to prepare graphene aggregate sol. The anode and cathode plates are separated by a plastic mesh, and the effective current density is controlled at 100 A / m. 2The power supply pulse frequency is 60Hz; the effective voltage is 20V; the temperature is controlled at 60℃; the oxidation reaction ends when the concentration of graphene sol reaches 0.7% after 200 hours of reaction, and the solution in the tank is graphene oxide sol.

[0012] According to an embodiment of the present invention, the trace elements include calcium, magnesium, iron, manganese, zinc, copper, boron, etc. The weight percentage of each element in the trace elements is: calcium 10-30%, magnesium 10-30%, iron 20-30%, manganese 10-25%, zinc 10-20%, copper 5-15%, boron 5-15%, molybdenum 5-20%; preferably, calcium 10-30%, magnesium 10-20%, iron 20-25%, manganese 15-25%, zinc 10-15%, copper 5-15%, boron 5-10%, molybdenum 5-15%, exemplarily 20:20:25:15:15:10:10:10.

[0013] The present invention also provides a method for preparing the graphene sol-coupled amino acid trace element composite material, comprising the following steps: (1) Preparation of graphene oxide sol: The graphene oxide nano sol was prepared by following the above method and graphene oxide nano sol was prepared for use. (2) Mixing reaction of amino acids and graphene oxide sol: Mix amino acids with the graphene oxide nanosol prepared in step (1), heat to 60-80 °C and stir continuously for 2-6 hours; In step (2), the reaction temperature is preferably 65-75℃, with 65℃ being an example; the reaction time is preferably 2-3 hours, with 2 hours being an example. (3) Nitrogen source (urea), phosphorus source (potassium dihydrogen phosphate), potassium source (potassium sulfate) and trace element source (Ca(NO3)2·4H2O, Mg(NO3)2·6H2O, CuSO4·5H2O, ZnSO4·7H2O, Mn(NO3)2·4H2O, FeSO4·7H2O, (NH4)2B4O7, (NH4)2MoO4) are added to the raw materials obtained in step (2) according to the above weight ratio, and placed in a mixing reactor and heated to 30-50 ℃ and continuously stirred to carry out a thorough mixing reaction for 1-6 hours to obtain graphene sol coupled amino acid trace element composite material; In step (3), the reaction temperature is preferably 50-60℃, with 55℃ being an example; the reaction time is preferably 2-3 hours, with 2 hours being an example.

[0014] The present invention also provides the application of the graphene sol-coupled amino acid trace element composite material in the preparation of agricultural fertilizers.

[0015] The present invention also provides an agricultural fertilizer comprising the graphene sol-coupled amino acid trace element composite material.

[0016] The beneficial effects of this invention are: The high specific surface area and excellent water absorption of graphene oxide, combined with the superior conductivity of amino acids within plants, allow for ion exchange between elements in metal hydrate sols and amino acid graphene oxide sols, making them more readily absorbed by plants. This results in higher fertilizer efficiency compared to ordinary fertilizers, demonstrating greater application value. Therefore, this invention designs and synthesizes a micronutrient fertilizer containing graphene oxide and amino acids, exhibiting outstanding water retention properties and a micronutrient-stabilizing graphene sol coupled with amino acids. The preparation method of this composite material is simple, convenient, and suitable for large-scale production. The application of this composite material as a fertilizer is beneficial for further utilizing land resources. Attached Figure Description

[0017] Figure 1 Photos of Impatiens seedlings before and after use of the composite material prepared in Example 3 of this invention. Detailed Implementation

[0018] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanatory of the present invention, and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0019] Unless otherwise stated, the raw materials and reagents used in the following examples are commercially available products or can be prepared by known methods.

[0020] In the preparation of graphene sol coupled with amino acid trace element composite materials, the graphene is a self-made graphene oxide sol, the amino acid is a commercially available amino acid, and the trace element metal salt hydrates are Ca(NO3)2·4H2O, Mg(NO3)2·6H2O, CuSO4·5H2O, ZnSO4·7H2O, Mn(NO3)2·4H2O, FeSO4·7H2O, (NH4)2B4O7, and (NH4)2MoO4.

[0021] The performance testing procedures for each composite material in the following examples are as follows: The fertilization test results of graphene sol-coupled amino acid trace element composite materials are as follows: All plants (impatiens) were maintained at a temperature of 22℃ with a photoperiod of 16 / 8 h (day / night). For the first four weeks of growth, the plants were watered every 5 days with either a 300-fold diluted amino acid-trace element composite material (without graphene sol) or a 300-fold diluted graphene sol-coupled amino acid-trace element composite material, once each time. From the fifth week onwards, the plants were watered every 3 days with 100 mL of water each time. Data were measured and analyzed on day 30 of growth.

[0022] The amino acid trace element composite material without graphene sol differs from the embodiments only in that it does not contain graphene oxide nanosol.

[0023] Example 1 A graphene sol-coupled amino acid trace element composite material, wherein the components, by weight, include: 90 parts of graphene oxide nanosol (solid content of 0.7%), 20 parts of histidine, 15 parts of nitrogen, 10 parts of phosphorus, 10 parts of potassium, 9 parts of medium elements, and 5 parts of trace elements (calcium:magnesium:iron:manganese:zinc:copper:boron:molybdenum weight ratio of 20:20:25:15:15:10:10:10).

[0024] The method for preparing the graphene sol-coupled amino acid trace element composite material includes the following steps: (1) The preparation method of graphene oxide nanosol is as follows: According to patent document CN106587018B, graphene oxide solution is prepared by high-frequency AC pulse method; firstly, anode and cathode plates of high-purity graphite with dimensions of 600mm×300mm×80mm are placed in an electrolytic oxidation tank, with a distance of 70mm between the anode and cathode plates. Then, 0.09% sulfuric acid electrolyte is poured into the tank, the power is turned on, and electrolytic oxidation is carried out to prepare graphene aggregate sol. The anode and cathode plates are separated by a plastic mesh, and the effective current density is controlled at 100 A / m. 2 The power supply pulse frequency is 60 Hz; the effective voltage is 20 V; and the temperature is controlled at 60 ℃. The oxidation reaction ends when the concentration of the graphene sol reaches 0.7% after 200 hours of reaction, and the solution in the tank is graphene oxide sol. (2) Mixing reaction of amino acids and graphene oxide sol: Mix amino acids with the graphene oxide nanosol prepared in step (1), heat and stir at 65°C for 2 hours. (3) Nitrogen, phosphorus, potassium and trace elements are added to the raw materials obtained in step (2) according to the formula ratio, and put into a mixing reactor to be fully mixed and reacted at 55°C for 2 hours to obtain graphene sol coupled amino acid trace element composite material.

[0025] The composite material of this embodiment was used to test the performance of plant seedling fertilizer. It was found that the leaf area of ​​the seedlings increased significantly by 153.2% (amino acid trace element fertilizer without graphene sol) and 218.5% (graphene sol coupled amino acid trace element composite material) compared with the control group (only distilled water was added).

[0026] Example 2 A graphene sol-coupled amino acid trace element composite material, by weight, comprises 90 parts of graphene oxide nanosol (solid content of 0.7%), 20 parts of histidine, 15 parts of nitrogen, 10 parts of phosphorus, 10 parts of potassium, 9 parts of medium elements, and 9 parts of trace elements (calcium:magnesium:iron:manganese:zinc:copper:boron:molybdenum weight ratio of 20:20:25:15:15:10:10:10).

[0027] The method for preparing the graphene sol-coupled amino acid trace element composite material includes the following steps: (1) The preparation method of graphene oxide nanosol is as follows: According to patent document CN106587018B, graphene oxide solution is prepared by high-frequency AC pulse method; firstly, anode and cathode plates of high-purity graphite with dimensions of 600mm×300mm×80mm are placed in an electrolytic oxidation tank, with a distance of 70mm between the anode and cathode plates. Then, 0.09% sulfuric acid electrolyte is poured into the tank, the power is turned on, and electrolytic oxidation is carried out to prepare graphene aggregate sol. The anode and cathode plates are separated by a plastic mesh, and the effective current density is controlled at 100 A / m. 2 The power supply pulse frequency is 60 Hz; the effective voltage is 20 V; and the temperature is controlled at 60 ℃. The oxidation reaction ends when the concentration of the graphene sol reaches 0.7% after 200 hours of reaction, and the solution in the tank is graphene oxide sol. (2) Mixing reaction of amino acids and graphene oxide sol: Mix amino acids with the graphene oxide nanosol prepared in step (1), heat and stir at 65°C for 2 hours. (3) Nitrogen, phosphorus, potassium and trace elements are added to the raw materials obtained in step (2) according to the formula ratio, and put into a mixing reactor to be fully mixed and reacted at 55°C for 2 hours to obtain graphene sol coupled amino acid trace element composite material.

[0028] The composite material of this embodiment was used to test the performance of plant seedling fertilizer. It was found that the leaf area of ​​the seedlings increased significantly by 158.4% (amino acid trace element fertilizer without graphene sol) and 234.3% (graphene sol coupled amino acid trace element composite material) compared with the control group (only distilled water was added).

[0029] Example 3 A graphene sol-coupled amino acid trace element composite material, by weight, comprises: 90 parts of graphene oxide nanosol (solid content of 0.7%), 20 parts of histidine, 15 parts of nitrogen, 10 parts of phosphorus, 10 parts of potassium, 9 parts of medium elements, and 13 parts of trace elements (calcium:magnesium:iron:manganese:zinc:copper:boron:molybdenum weight ratio of 20:20:25:15:15:10:10:10).

[0030] The method for preparing the graphene sol-coupled amino acid trace element composite material includes the following steps: (1) The preparation method of graphene oxide nanosol is as follows: According to patent document CN106587018B, graphene oxide solution is prepared by high-frequency AC pulse method; firstly, anode and cathode plates of high-purity graphite with dimensions of 600mm×300mm×80mm are placed in an electrolytic oxidation tank, with a distance of 70mm between the anode and cathode plates. Then, 0.09% sulfuric acid electrolyte is poured into the tank, the power is turned on, and electrolytic oxidation is carried out to prepare graphene aggregate sol. The anode and cathode plates are separated by a plastic mesh, and the effective current density is controlled at 100 A / m. 2 The power supply pulse frequency is 60 Hz; the effective voltage is 20 V; and the temperature is controlled at 60 ℃. The oxidation reaction ends when the concentration of the graphene sol reaches 0.7% after 200 hours of reaction, and the solution in the tank is graphene oxide sol. (2) Mixing reaction of amino acids and graphene oxide sol: Mix amino acids with the graphene oxide nanosol prepared in step (1), heat and stir at 65°C for 2 hours. (3) Nitrogen, phosphorus, potassium and trace elements are added to the raw materials obtained in step (2) according to the formula ratio, and put into a mixing reactor to be fully mixed and reacted at 55°C for 2 hours to obtain graphene sol coupled amino acid trace element composite material.

[0031] The composite material of this embodiment was used to test the performance of plant seedling fertilizer. It was found that the leaf area of ​​the seedlings increased significantly by 162.4% (amino acid trace element fertilizer without graphene sol) and 253.2% (graphene sol coupled amino acid trace element composite material) compared with the control group (only distilled water was added).

[0032] Figure 1 The performance of the graphene sol-coupled amino acid trace element composite material prepared in Example 3 was tested, and photos of Impatiens flowers before and after use were taken. Figure 1 It can be clearly seen that the leaf area of ​​seedlings using graphene sol-coupled amino acid trace element composite materials ( Figure 1 (c) and control group ( Figure 1 (a) and seedlings of traditional fertilizers containing amino acid trace element composites without graphene sol (a)Figure 1 (b) is significantly larger than that.

[0033] Example 4 A graphene sol-coupled amino acid trace element composite material, by weight, comprises: 90 parts of graphene oxide nanosol (solid content of 0.7%), 20 parts of histidine, 15 parts of nitrogen, 10 parts of phosphorus, 10 parts of potassium, 9 parts of medium elements, and 17 parts of trace elements (calcium:magnesium:iron:manganese:zinc:copper:boron:molybdenum weight ratio of 20:20:25:15:15:10:10:10).

[0034] The preparation method of the graphene sol coupled with amino acid trace element composite material includes the following steps: (1) The preparation method of graphene oxide nanosol is as follows: according to the patent document CN106587018B, graphene oxide solution is prepared by high frequency AC pulse method; firstly, the anode and cathode plates of high purity graphite with a size of 600mm×300mm×80mm are placed in the electrolytic oxidation tank, and the distance between the anode and cathode plates is 70mm. Then, 0.09% sulfuric acid electrolyte is poured into the tank, the power is turned on, and electrolytic oxidation is carried out to prepare graphene aggregate sol. The anode and cathode plates are separated by plastic mesh, and the effective current density is controlled at 100 A / m 2 The power supply pulse frequency is 60 Hz; the effective voltage is 20 V; and the temperature is controlled at 60 ℃. The oxidation reaction ends when the concentration of the graphene sol reaches 0.7% after 200 hours of reaction, and the solution in the tank is graphene oxide sol. (2) Mixing reaction of amino acids and graphene oxide sol: Mix amino acids with the graphene oxide nanosol prepared in step (1), heat and stir at 65°C for 2 hours. (3) Nitrogen, phosphorus, potassium and trace elements are added to the raw materials obtained in step (2) according to the formula ratio, and put into a mixing reactor to be fully mixed and reacted at 55°C for 2 hours to obtain graphene sol coupled amino acid trace element composite material.

[0035] The composite material of this embodiment was used to test the performance of plant seedling fertilizer. It was found that the leaf area of ​​the seedlings increased significantly by 159.7% (amino acid trace element fertilizer without graphene sol) and 241.3% (graphene sol coupled amino acid trace element composite material) compared with the control group (only distilled water was added).

[0036] As can be seen from the examples, by adjusting the parameters of the present invention, the preparation of graphene sol amino acid trace element composite materials can be achieved, and the performance is basically the same as that in Example 3.

[0037] The exemplary embodiments of the present invention have been described above. However, the scope of protection of this application is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc., made by those skilled in the art within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A graphene sol-coupled amino acid trace element composite material, characterized in that, By weight, it includes the following components: 30-100 parts graphene oxide sol, 10-90 parts amino acids, 15-50 parts nitrogen, 5-30 parts phosphorus, 5-30 parts potassium, and 5-40 parts trace elements.

2. The graphene sol-coupled amino acid trace element composite material according to claim 1, characterized in that, The composition includes 60-90 parts of graphene oxide sol, 10-40 parts of amino acids, 15-20 parts of nitrogen, 10-20 parts of phosphorus, 10-20 parts of potassium, and / or 10-25 parts of trace elements.

3. The graphene sol-coupled amino acid trace element composite material according to claim 1, characterized in that, The solid content of the graphene oxide sol is 0.3-1.0%, for example, 0.5-0.8%; And / or, the amino acid is selected from glycine, glutamic acid or histidine.

4. The graphene sol-coupled amino acid trace element composite material according to claim 1, characterized in that, By weight, the composite material comprises the following components: 90 parts graphene oxide sol, 20 parts amino acids, 15 parts nitrogen, 10 parts phosphorus, 10 parts potassium, 9 parts medium-mass elements, and 5 parts trace elements; or... By weight, the composite material comprises the following components: 90 parts graphene oxide sol, 20 parts amino acids, 15 parts nitrogen, 10 parts phosphorus, 10 parts potassium, 9 parts medium-mass elements, and 9 parts trace elements; or... The composite material comprises the following components by weight: 90 parts graphene oxide sol, 20 parts amino acids, 15 parts nitrogen, 10 parts phosphorus, 10 parts potassium, 9 parts medium-weight elements, and 13 parts trace elements.

5. The graphene sol-coupled amino acid trace element composite material according to claim 1, characterized in that, The graphene oxide sol was prepared by the following method: First, anode and cathode plates of high-purity graphite with dimensions of 600mm×300mm×80mm were placed in an electrolytic oxidation tank, with a distance of 70mm between the anode and cathode plates; then, 0.09% sulfuric acid electrolyte was poured into the tank, the power was turned on, and electrolytic oxidation was carried out to prepare graphene aggregate sol. The anode and cathode plates were separated by a plastic mesh, and the effective current density was controlled at 100 A / m. 2 ; The power supply pulse frequency is 60 Hz; the effective voltage is 20 V; the temperature is controlled at 60℃; the oxidation reaction ends when the concentration of graphene sol reaches 0.7% after 200 hours of reaction, and the solution in the tank is graphene oxide sol.

6. The graphene sol-coupled amino acid trace element composite material according to claim 1, characterized in that, The trace elements include calcium, magnesium, iron, manganese, zinc, copper, and boron.

7. The graphene sol-coupled amino acid trace element composite material according to claim 6, characterized in that, The weight percentages of each element in the micronutrient composition are as follows: calcium 10-30%, magnesium 10-30%, iron 20-30%, manganese 10-25%, zinc 10-20%, copper 5-15%, boron 5-15%, molybdenum 5-20%.

8. The method for preparing the graphene sol-coupled amino acid trace element composite material according to any one of claims 1-7, characterized in that, Includes the following steps: (1) Preparation of graphene oxide sol: The preparation method of graphene oxide nanosol in claim 5 is followed to obtain graphene oxide sol for later use. (2) Mixing reaction of amino acids and graphene oxide sol: Mix amino acids with the graphene oxide nanosol prepared in step (1), heat to 60-80 ℃ and stir continuously for 2-6 hours; (3) Nitrogen source (urea), phosphorus source (potassium dihydrogen phosphate), potassium source (potassium sulfate) and trace element source (Ca(NO3)2·4H2O, Mg(NO3)2·6H2O, CuSO4·5H2O, ZnSO4·7H2O, Mn(NO3)2·4H2O, FeSO4·7H2O, (NH4)2B4O7, (NH4)2MoO4) are added to the raw materials obtained in step (2) according to the above weight ratio. They are placed in a mixing reactor and heated to 30-50 ℃ and stirred continuously for 1-6 hours to fully mix and react, so as to obtain graphene sol coupled amino acid trace element composite material.

9. The application of the graphene sol-coupled amino acid trace element composite material according to any one of claims 1-7 in the preparation of agricultural fertilizers.

10. An agricultural fertilizer comprising the graphene sol-coupled amino acid trace element composite material as described in any one of claims 1-7.

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