CN119505123B - Application of bisimidazolyl polyionic liquid functionalized hydrothermal carbon in the preparation of pesticide slow-release agents - Google Patents

Abstract

The invention discloses a kind of application of bisimidazolyl polyionic liquid functionalized hydrothermal charcoal in preparing pesticide slow-release agent, the preparation method of the functionalized hydrothermal charcoal includes：Take hydrothermal carbonization method to carry out carbonization reaction to bamboo powder and hydrochloric acid solution, reaction obtained product adds alkali liquor stirring, filters and washes to filtrate for neutrality, obtains hydrothermal bamboo charcoal；Dichloromethane and 1 vinylimidazole are put into reactor and react, and after the completion of reaction, monomer N, N'-methylene-bis(1-(3 vinylimidazole)) chlorine (DVim-Cl) is prepared；Take above-mentioned hydrothermal bamboo charcoal and DVim-Cl, add initiator and solvent, put into reactor and heat reaction, obtain target compound.The slow-release agent prepared by the present invention can effectively load herbicide, has good weeding activity, and load capacity is up to 565mg/g, and load rate reaches 36.1%, has good application prospect in pesticide slow-release field.

Description

Application of diimidazole-based polyion liquid functionalized hydrothermal carbon in preparation of pesticide sustained release agent

Technical Field

The invention relates to application of functionalized hydrothermal carbon, in particular to application of diimidazole-based polyion liquid functionalized hydrothermal carbon in preparation of pesticide slow release agent.

Background

Pesticides are widely used in agriculture to control pests, fungi and weeds, and have serious negative effects on ecological balance systems and public health. Thus, there is a need for more efficient and safer methods of pesticide use to address these problems. The traditional pesticide formulation can rapidly reduce the pesticide effect after pesticide release, and cause serious harm to the environment, for example, emulsifiable concentrate can lead to the use of a large amount of benzene solvents, and dust pollution can be generated when powder and wettable powder are used. These formulations are harmful to the health of the applicator due to environmental pollution after use, and have a short duration of time, require an increased dosage and frequency of use, result in increased production costs and pesticide residues, and also are resistant to pests, and reduce the life of pesticides, so that the pesticide pollution must be prevented by an appropriate application method, an effective method is the development of Controlled Release Formulations (CRFs) of pesticides, which has been receiving increasing attention in recent years. CRFs can maintain pesticides above effective levels for long periods of time, which will help reduce herbicide consumption and increase their biological activity.

The adsorption type sustained release agent is a pesticide formulation obtained by using an adsorption carrier as a reservoir for a pesticide. The herbicide is adsorbed on the carrier so that unnecessary loss of the highly water-soluble herbicide such as 2,4-D Na can be avoided, and encapsulation thereof in a suitable carrier can enhance the effectiveness of the active ingredient and improve its photostability. Therefore, how to develop a high-efficiency adsorption type sustained release agent is a technical problem to be solved at present.

Disclosure of Invention

The invention aims to provide the application of the diimidazole-based polyion liquid hydrothermal carbon in the preparation of the pesticide slow release agent, and the functionalized hydrothermal carbon can improve the weeding efficiency and reduce the side effect of the pesticide in the pesticide slow release process.

The technical scheme is that the application of the diimidazole-based polyion liquid functionalized hydrothermal carbon in preparing pesticide sustained release agents is that the preparation method of the diimidazole-based polyion liquid functionalized hydrothermal carbon comprises the following steps:

(1) Carbonizing bamboo powder and hydrochloric acid solution by adopting a hydrothermal carbonization method, adding alkali liquor into the product obtained by the reaction, stirring, filtering and washing until filtrate is neutral, thus obtaining hydrothermal bamboo charcoal;

and (3) putting methylene dichloride and 1-vinylimidazole into a reaction kettle for reaction, and filtering after the reaction is finished to obtain monomer N, N' -methylene-bis (1- (3-vinylimidazole)) chloride (DVim-Cl).

(2) And adding an initiator and a solvent into the hydrothermal bamboo charcoal and DVim-Cl, and placing the mixture into a reaction kettle for heating reaction to obtain the product of the bis-imidazolyl polyion liquid functionalized hydrothermal charcoal.

The synthetic route for the above reaction is as follows:

further, the concentration of the bamboo powder in the step (1) in the hydrochloric acid solution is 0.2-0.3g/mL, and the concentration of the hydrochloric acid is 0.5-1.0mol/L.

Further, the reaction temperature of the carbonization reaction in the step (1) is 200-220 ℃, the carbonization time is 12-24h, the alkali liquor stirring time is 2-4h, and the alkali liquor is sodium hydroxide solution with the concentration of 0.2-0.25mol/L.

Further, the molar ratio of the dichloromethane to the 1-vinyl imidazole in the step (1) is 1-3:2-4, the reaction temperature is 100-120 ℃ and the reaction time is 12-80h.

Further, when the N, N ' -methylene-bis (1- (3-vinyl imidazole)) chlorine monomer is synthesized, the N, N ' -methylene-bis (1- (3-vinyl imidazole)) chlorine monomer can be prepared by a low-temperature solvent-free method, or can be prepared by adding additional solvents (such as tetrahydrofuran, acetonitrile and the like) except for two raw materials, wherein the N, N ' -methylene-bis (1- (3-vinyl imidazole)) chlorine monomer is preferably synthesized by the low-temperature solvent-free method, so that the technical effects of environmental protection, reaction efficiency improvement and production cost reduction can be realized.

Further, the mass ratio of the hydrothermal carbon to DVim-Cl to the initiator in the step (2) is 10-12:15-25:1.4-2.5.

Further, the solvent in the step (2) is a mixed solvent of water and dimethyl sulfoxide, and the volume ratio of the water to the dimethyl sulfoxide is 1-2:1-2.

Further, after the reaction in the step (2), filtering, washing with anhydrous ethyl acetate, and drying filter residues to obtain the target compound

Further, the drying temperature is 60-80 ℃.

Further, the pesticide slow release agent comprises double imidazolyl polyion liquid functionalized hydrothermal carbon, the double imidazolyl polyion liquid functionalized hydrothermal carbon is used as a pesticide carrier, and the pesticide is 2,4-D sodium.

Further, the pesticide slow release agent comprises a salt containing Cl ^- and the like, and is used for adjusting the pesticide slow release rate.

Further, the pesticide slow release agent can be controllably released by adjusting the pH value, and the pH value is=5-7.

The invention principle is that the surface of the hydrothermal carbon contains rich hydroxyl, carboxyl and other functional groups, and the potential and polarity of the surface of the hydrothermal carbon can be changed by introducing the nitrogen-containing groups into the surface of the hydrothermal carbon, so that the slow release agent is positively charged and hydrophilic, and the adsorption and loading capacity of the modified hydrothermal carbon on anionic pesticides are improved through electrostatic interaction. According to the invention, azodiisobutyronitrile is used as an initiator, N '-methylene-bis (1- (3-vinyl imidazole)) chloride graft copolymerization is initiated by a low-temperature solvothermal method to prepare poly (N, N' -methylene-bis (1- (3-vinyl imidazole)) chloride) functionalized hydrothermal carbon on the surface of the hydrothermal carbon, so as to obtain the bisimidazolyl polyion liquid functionalized hydrothermal carbon carrier. The double imidazolyl polyion liquid functionalized hydrothermal carbon is accompanied with the change of the pH of a solution, the Zeta potential on the surface of a carrier is obviously changed, and the electrostatic acting force between the carrier and pesticide 2,4-D Na and the like is influenced by the change of the environmental pH and the ionic strength, so that the pesticide slow release agent has multiple stimulus responsiveness of the pH and the ionic strength. The controlled release of the pesticide slow release agent is realized by controlling the pH value or the ionic strength of the environment.

The invention has the advantages that compared with the prior art, the invention has the advantages that (1) the N, N' -methylene-bis (1- (3-vinyl imidazole)) chlorine monomer is synthesized by adopting a low-temperature solvent-free method, the environment is protected, the reaction efficiency is improved, the production cost is reduced, (2) the slow release agent has stable performance, the diimidazolyl polyion liquid functionalized hydrothermal carbon is synthesized by adopting a low-temperature solvothermal method, the loading capacity of 2,4-D Na of pesticides is up to 565mg/g, the loading rate is up to more than 36 percent, (3) the slow release agent can regulate and control the drug release rate by changing the pH value and the ionic strength, the drug effect period is prolonged, the duration time can be up to more than 35 hours, the utilization efficiency of the herbicide can be improved, (4) the carrier raw material is waste biomass, the source is wide and the price is low, the method for preparing the hydrothermal bamboo charcoal is carried out under the closed condition, the reaction process is environment-friendly, and (5) the preparation method and the equipment of the slow release agent are simple, and are expected to be widely applied in the agricultural field.

Drawings

FIG. 1 is a FTIR spectrum of a hydrothermal bamboo charcoal (HC), a bis-imidazolyl polyion liquid functionalized hydrothermal bamboo charcoal slow release carrier (BIPIL-HC), N, N' -methylene-bis (1- (3-vinylimidazole)) chloride (DVim-Cl), a bis-imidazolyl polyion liquid functionalized hydrothermal charcoal pesticide slow release agent (BIPIL-HC-2, 4-D Na) and a pesticide 2,4-D Na;

FIG. 2 is a graph of BIPIL-HC load capacity versus different initial concentrations of 2,4-D Na;

FIG. 3 is a plot of Zeta potential of BIPIL-HC versus load capacity for 2,4-D Na at various pH values;

FIG. 4 is a graph of the slow release behavior of BIPIL-HC-2,4-D Na in different solutions, wherein a) is a graph of the slow release of BIPIL-HC-2,4-D Na at different pH values, b) is a graph of the slow release of BIPIL-HC-2,4-D Na in salt solutions;

FIG. 5 is a graph of BIPIL-HC-2,4-D Na herbicidal activity.

Detailed Description

The technical scheme of the invention is further described below with reference to the accompanying drawings.

Example 1

The preparation method of the bisimidazolyl polyion liquid functionalized hydrothermal carbon pesticide slow release agent comprises the following steps:

Weighing 40g of bamboo powder in a 500mL high-pressure reaction kettle with a polytetrafluoroethylene lining, adding 160mL of hydrochloric acid solution with the concentration of 1mol/L, uniformly stirring, reacting for 24 hours at 200 ℃, cooling, suction filtering, washing with deionized water, suction filtering, adding 400mL of sodium hydroxide solution with the concentration of 0.2mol/L, stirring for 2 hours, cooling, suction filtering, washing with deionized water until the filtrate reaches a stable pH value, suction filtering, and drying at 60 ℃ to obtain hydrothermal bamboo charcoal (HC);

9.41g of 1-vinylimidazole and 6.37g of methylene chloride are weighed and uniformly stirred in a 100mL high-pressure reaction kettle lined with polytetrafluoroethylene, reacted for 72 hours at 100 ℃, cooled and filtered to obtain a monomer N, N' -methylene-bis (1- (3-vinylimidazole) chloride) (DVim-Cl).

The preparation method comprises the steps of weighing 1g of hot bamboo charcoal, 2.5g of DVim-Cl, 0.25g of azodiisobutyronitrile, 10mL of mixed solution of deionized water and dimethyl sulfoxide, pouring the mixed solution into a 100mL high-pressure reaction kettle with a polytetrafluoroethylene lining, heating at 100 ℃ for reaction for 24 hours, filtering with deionized water after cooling to room temperature, washing to neutrality, and drying the obtained sample in a60 ℃ oven to obtain the diimidazole-based polyion liquid functionalized hot charcoal pesticide slow-release carrier (BIPIL-HC).

Example 2

The preparation method of the bisimidazolyl polyion liquid functionalized hydrothermal carbon pesticide slow release agent comprises the following steps:

Weighing 40g of bamboo powder in a 500mL high-pressure reaction kettle with a polytetrafluoroethylene lining, adding 180mL of hydrochloric acid solution with the concentration of 1mol/L, uniformly stirring, reacting for 24 hours at 200 ℃, cooling, suction filtering, washing with deionized water, suction filtering, adding 400mL of sodium hydroxide solution with the concentration of 0.2mol/L, stirring for 2 hours, cooling, suction filtering, washing with deionized water until the filtrate reaches a stable pH value, suction filtering, and drying at 60 ℃ to obtain hydrothermal bamboo charcoal (HC);

9.41g of 1-vinylimidazole and 6.37g of methylene dichloride are weighed and uniformly stirred in a 100mL high-pressure reaction kettle lined with polytetrafluoroethylene, reacted for 72 hours at 100 ℃, cooled, filtered by suction, and washed with anhydrous ethyl acetate to obtain a monomer N, N' -methylene-bis (1- (3-vinylimidazole) chloride) (DVim-Cl).

The preparation method comprises the steps of weighing 1g of hot bamboo charcoal, 2g of DVim-Cl, 0.14g of azodiisobutyronitrile, 10mL of mixed solution of deionized water and dimethyl sulfoxide, pouring the mixed solution into a 100mL high-pressure reaction kettle with a polytetrafluoroethylene lining, heating at 100 ℃ for reaction for 24 hours, cooling to room temperature, filtering with deionized water, washing to neutrality, and drying the obtained sample in a 60 ℃ oven to obtain the diimidazolyl polyion liquid functionalized hot charcoal pesticide slow release carrier (BIPIL-HC).

Example 3

The preparation method of the bisimidazolyl polyion liquid functionalized hydrothermal carbon pesticide slow release agent comprises the following steps:

weighing 40g of bamboo powder in a 500mL high-pressure reaction kettle with a polytetrafluoroethylene lining, adding 200mL of hydrochloric acid solution with the concentration of 1mol/L, uniformly stirring, reacting for 24 hours at 200 ℃, cooling, suction filtering, washing with deionized water, suction filtering, adding 400mL of sodium hydroxide solution with the concentration of 0.2mol/L, stirring for 2 hours, cooling, suction filtering, washing with deionized water until the filtrate reaches a stable pH value, suction filtering, and drying at 60 ℃ to obtain hydrothermal bamboo charcoal (HC);

9.41g of 1-vinylimidazole and 6.37g of methylene chloride are weighed and stirred uniformly in a 100mL high-pressure reaction kettle with a polytetrafluoroethylene lining, reacted for 72 hours at 100 ℃, cooled, filtered by suction, and washed with anhydrous ethyl acetate to obtain monomer N, N' -methylene-bis (1- (3-vinylimidazole)) chloride (DVim-Cl).

The preparation method comprises the steps of weighing 1g of hot bamboo charcoal, 2.5g of DVim-Cl, 0.25g of azodiisobutyronitrile, 20mL of mixed solution of deionized water and dimethyl sulfoxide, pouring the mixed solution into a 100mL high-pressure reaction kettle with a polytetrafluoroethylene lining, heating at 100 ℃ for reaction for 24 hours, filtering with deionized water after cooling to room temperature, washing to neutrality, and drying the obtained sample in a60 ℃ oven to obtain the diimidazole-based polyion liquid functionalized hot charcoal pesticide slow-release carrier (BIPIL-HC).

The structural characterization and test result analysis are carried out on the bisimidazolyl polyion liquid functionalized hydrothermal carbon pesticide slow release agent prepared in the embodiment 1.

(1)FTIR

The infrared characterization was performed on samples before and after modification of the hydrothermal bamboo charcoal and before and after loading of pesticides, see fig. 1. The method for preparing the sustained release agent by using the hydrothermal bamboo charcoal loaded pesticide comprises the steps of weighing 0.40g of the hydrothermal bamboo charcoal pesticide sustained release carrier in the embodiment 1 to a conical flask, simultaneously adding 500ml of 2,4-D Na solution with the concentration of 500mg/L, oscillating for 12 hours in a 100rpm oscillator, filtering, and drying to obtain the 2,4-D Na sustained release agent (BIPIL-HC-2, 4-D Na). The curves in the figure respectively show hydrothermal bamboo charcoal (HC), N' -methylene-bis (1- (3-vinyl imidazole)) chloride (DVim-Cl), a diimidazolyl polyion liquid functionalized hydrothermal charcoal pesticide slow-release carrier (BIPIL-HC), a diimidazolyl polyion liquid functionalized hydrothermal charcoal pesticide slow-release agent (BIPIL-HC-2, 4-D Na) and pesticide 2,4-D Na.

Characteristic peaks of HC at 3406, 2958, 1689, 1614 and 1384cm ^–1 all represent the tensile vibration of O-H, aliphatic C-H, C =o and c=c and the bending vibration of methylene, respectively.

Characteristic peaks of DVim-Cl at 1648, 1561 and 1172cm ^–1 are c= N, C =c and C-N stretching vibrations of imidazole. The peak at 935cm ^–1 is the C-H bending vibration peak of vinyl. After HC modification, the peaks changed significantly. The characteristic peak of imidazole appears on BIPIL-HC surface, and the C-H bending vibration peak of vinyl at 935cm ^–1 disappears, confirming that vinyl participates in cross-linking polymerization.

Characteristic peaks at 1620, 1481, 1337, 1038 and 795cm ^–1 for 2,4-D Na are c=c stretching vibration on the aromatic ring, plane bending vibration of C-H, carboxylate, stretching vibration of C-O-C, C-Cl, respectively. After loading with 2,4-D Na, the characteristic peaks are red shifted to 1613, 1346 and 805cm ^–1, respectively. Indicating that 2,4-D Na is loaded on BIPIL-HC.

(2) Influence of initial concentration on adsorption

The loadings at the different initial concentrations were determined and calculated by shaking 40mg BIPIL-HC and 50ml of 2,4-D Na solution (25, 50, 100, 200, 300, 400, 500, 600, 700, 800, 900mg/L, t=298 k, ph=5) for 12 h.

FIG. 2 is a graph showing the effect of initial concentration on BIPIL-HC loaded 2,4-D Na, from which it can be seen that the loading for 2,4-D Na increases significantly with increasing concentration, and at 298K, with increasing initial concentration from 25mg/L to 900mg/L, the loading increases from 28.35mg/g to 565.10mg/g.

(3) Zeta potential of BIPIL-HC and load potential diagram for 2,4-D Na at different pH values

The Zeta potential of BIPIL-HC changes from +35.2eV to-3.17 eV in the pH range of 2-12, and the zero point charge (pH _PZC) is about 11.5. As shown in FIG. 3, BIPIL-HC assumes a positive charge when the pH is <11.5, and vice versa. The high pH _PZC indicates that BIPIL-HC can be loaded with the pesticide 2,4-D Na over a wide pH range. When the pH value of the solution is in the range of 4-9, the solution shows higher loading capacity to 2,4-D Na.

(4) Influence of different environmental conditions on slow release behavior of BIPIL-HC-2,4-D Na slow release agent

The slow release study was performed on BIPIL-HC-2,4-D Na, 40.0mg BIPIL-HC-2,4-D Na (2, 4-D Na loading 36.1%) was weighed into a 8000g/mol molecular weight cut-off dialysis bag, the dialysis bag was placed in a 250mL beaker, 150mL of different pH slow release solutions (pH= 5.0,7.0 and 9.0, adjusted by 0.1M NaOH and 0.1M HCl) or saline solution (0.02M NaCl, pH around 7.0) was added, shaking was performed in a shaker at 100rpm at room temperature, 5mL of supernatant was taken at intervals, and 5mL of the same solution was simultaneously added. Subsequently, the filtrate was measured for the concentration of 2.4-D at a wavelength of 229.5nm using an ultraviolet-visible spectrophotometer and its cumulative release rate was calculated by the formula.

As shown in fig. 4 a), the BIPIL-HC-2,4-D Na sustained release agent gradually increases in cumulative release rate with time under different pH conditions, the sustained release rate after 35 hours is 23.09% -31.09% under the condition of ph=5.0-7.0, the sustained release rate after 35 hours is 85.10% under the condition of ph=9.0, and the release rate is faster in ph=9.0 than in the condition of ph=5.0-7.0. From FIG. 4 a) it can be seen that the pH of the solution has a large influence on the BIPIL-HC-2,4-D Na slow release capacity.

As can be seen from FIG. 4 b), the effect of ionic strength on release performance was investigated using a 0.02M NaCl solution and water as a control as release medium. The release rate of BIPIL-HC-2,4-D Na at 0.02M NaCl is significantly different from that of deionized water as a release medium, the cumulative release rate of 0.02M NaCl as a release medium reaches equilibrium after 34 hours, and the cumulative release rate of deionized water as a release medium is only 22% after 34 hours. Thus, the ionic strength significantly affects the release rate of BIPIL-HC-2,4-D Na. The BIPIL-HC-2,4-D Na release showed significant dual pH and ionic strength response characteristics.

(5) Herbicidal activity

Weighing 0.40g of the hydrothermal carbon pesticide slow release carrier, adding 500ml of 2,4-D Na solution with the concentration of 500mg/L into a conical flask, oscillating for 12 hours in a 100rpm oscillator, filtering, and drying to obtain the 2,4-D Na slow release agent (BIPIL-HC-2, 4-D Na).

Five groups of 9cm diameter petri dishes were prepared, each with 10ml of test solution (a: deionized water, b:100ppm2,4-D Na solution, c:0.02M NaCl solution, D: deionized water + BIPIL-HC-2,4-D Na, e:0.02M NaCl solution + BIPIL-HC-2,4-D Na, wherein the amounts of 2,4-D Na in groups b and D/e were the same, and the amounts of slow-release agent carriers in groups D and e were the same), then a layer of filter paper was placed inside the petri dishes, and 10 oilseed rape seeds were placed on each filter paper. Grown in an incubator at 26 ℃ with 85% humidity and with an illumination intensity (3000 lx). The first three days are completely dark, and the last five days are alternated with 12/12 days. The growth root length of rape under different conditions was measured and the fresh weight and dry weight of seeds were compared.

As shown in FIG. 5, the 0.02M NaCl solution has no side effect on the growth of rape and can obviously promote the growth of the rootstock of rape. In addition, BIPIL-HC has no obvious influence on rape growth, which shows that BIPIL-HC has good biological safety and is suitable for being used as a pesticide carrier. From the growth of rape, the root length, fresh weight and dry weight of rape after BIPIL-HC-2,4-D Na is applied in 0.02M NaCl medium are all lower than those of the rape after 2,4-D Na aqueous solution with the same dosage and concentration. These results indicate that BIPIL-HC-2,4-D Na has good herbicidal activity and is affected by the ionic strength of the released medium.

Claims (10)

1. The application of the diimidazole-based polyion liquid functionalized hydrothermal carbon in preparing pesticide sustained release agents is characterized in that the preparation method of the diimidazole-based polyion liquid functionalized hydrothermal carbon comprises the following steps:

(1) Carbonizing bamboo powder and hydrochloric acid solution by adopting a hydrothermal carbonization method, adding alkali liquor into the product obtained by the reaction, stirring, filtering and washing until filtrate is neutral, thus obtaining hydrothermal bamboo charcoal;

Putting dichloromethane and 1-vinylimidazole into a reaction kettle for reaction, and obtaining monomer N, N' -methylene-bis (1- (3-vinylimidazole)) chloride after the reaction is completed;

(2) And (3) taking the hydrothermal bamboo charcoal and N, N' -methylene-bis (1- (3-vinyl imidazole)) chloride, adding an initiator and a solvent, and placing the mixture into a reaction kettle for heating reaction to obtain the product bis-imidazolyl polyion liquid functionalized hydrothermal charcoal.

2. The application of the diimidazole-based polyion liquid functionalized hydrothermal carbon in preparing a pesticide slow release agent according to claim 1, wherein the concentration of the bamboo powder in the step (1) in a hydrochloric acid solution is 0.2-0.3g/mL, and the concentration of the hydrochloric acid solution is 0.5-1.0mol/L.

3. The application of the diimidazole-based polyion liquid functionalized hydrothermal carbon in preparing pesticide slow release agent according to claim 1, wherein the reaction temperature of the carbonization reaction in the step (1) is 200-220 ℃, the carbonization time is 12-24h, and the alkali liquor stirring time is 2-4h.

4. The application of the diimidazole-based polyion liquid functionalized hydrothermal carbon in preparing pesticide slow release agent according to claim 1, wherein the alkali liquid in the step (1) is sodium hydroxide solution, and the concentration of the alkali liquid is 0.2-0.25mol/L.

5. The application of the diimidazole-based polyion liquid functionalized hydrothermal carbon in preparing a pesticide slow release agent according to claim 1, wherein the molar ratio of the dichloromethane to the 1-vinylimidazole in the step (1) is 1-3:2-4.

6. The application of the diimidazole-based polyion liquid functionalized hydrothermal carbon in preparing a pesticide slow release agent according to claim 1, wherein the reaction temperature in the step (1) is 100-120 ℃ and the reaction time is 12-80h.

7. The application of the diimidazole-based polyion liquid functionalized hydrothermal carbon in preparing a pesticide slow release agent according to claim 1, wherein the target compound is obtained after filtering after the reaction in the step (2) is finished, washing with anhydrous ethyl acetate and drying filter residues.

8. The application of the diimidazole-based polyion liquid functionalized hydrothermal carbon in preparing a pesticide slow release agent according to claim 1, wherein the mass ratio of the hydrothermal carbon to the N, N' -methylene-bis (1- (3-vinylimidazole)) chloride to the azodiisobutyronitrile in the step (2) is 10-12:15-25:1.4-2.5.

9. The application of the diimidazole-based polyion liquid functionalized hydrothermal carbon in preparing a pesticide slow release agent according to claim 1, wherein the solvent in the step (2) is a mixed solvent of water and dimethyl sulfoxide, and the volume ratio of water to dimethyl sulfoxide is 1-2:1-2.

10. The use of diimidazole based polyionic liquid functionalized hydro-carbon according to claim 1, wherein the pesticide slow release agent further comprises a salt containing Cl ^-, and the pesticide is 2,4-D sodium.