Temperature-responsive polymer nano-composite hydrogen sulfide slow-release agent as well as preparation method and application thereof

Abstract

The invention discloses a temperature response type polymer nano-composite hydrogen sulfide slow-release agent as well as a preparation method and application thereof. The slow-release agent comprises a nano-material core and a coating layer coating the nano-material core, the nano material core is prepared from the following raw materials: a nano material with a photothermal effect, clay, sodium hydrosulfide, an H2S initiator and an adhesive, and the mass ratio of the clay to the nano material with the photothermal effect to the sodium hydrosulfide to the H2S initiator is (1-2): (1-2): (2-3): (4-6); the coating layer is prepared from the following raw materials: an alcohol-soluble high-molecular polymer and amino silicon oil. The invention provides the temperature response type polymer nano composite hydrogen sulfide slow-release agent with stable performance and controllable quality, the temperature is an activated molecule of a nano material, and the defects that the release speed of an H2S donor cannot be controlled, the release concentration of the donor is not easy to determine and the utilization rate is not high are overcome.

Description

Technical Field

[0001] The present invention relates to the technical field of sustained-release agents, and particularly relates to a temperature-responsive polymer nanocomposite hydrogen sulfide sustained-release agent, a preparation method thereof, and an application thereof. Background Art

[0002] Since hydrogen sulfide (H2S) gas was first discovered by researchers in 1713, for more than a hundred years thereafter, it has been widely regarded as an environmental air pollutant with a foul odor. H2S is mostly found in mining production and waste treatment operations. Therefore, in the early research on H2S, the main focus of attention was on the risks of excessive exposure of animals, plants, and microorganisms to H2S. It wasn't until the 1990s that the "stereotype" of H2S gradually changed. As the third gas signaling molecule discovered in organisms, H2S is considered to play a wide range of and crucial roles in animals and plants. Similar to the mechanisms of action of gas signaling molecules such as CO, NO, and CH4 discovered earlier, H2S has a strong toxic effect on organisms at high concentrations, and can cause the death of organisms in severe cases; while at low concentrations in the micromolar range, H2S plays positive roles such as signal transduction in animals and plants. At the end of the last century, the research on H2S in organisms mainly focused on animals, and the H2S signal was considered to be of great significance to the respiratory system, cardiovascular system, and nervous system. At the same time, for diseases occurring in the above systems such as lung cancer, myocarditis, and cognitive dysfunction, exogenous H2S has a significant alleviating effect. A variety of H2S drugs have been developed and applied in clinical medical treatment. Since 2000, more and more reports have shown that the signaling role of H2S in plants is significant. H2S has complex interactions with signaling pathways such as reactive oxygen species, NO signal, CO signal, Ca 2+ signal, plant hormones, etc. Therefore, a large number of literatures have begun to focus on the impact of exogenous H2S supplementation on plants in various environments. It has been found that exogenous H2S donors can promote the normal growth and development of plants under non-stress conditions, such as root growth, germination, fruiting, and stomatal regulation. Further research has found that under stress conditions, the supplementation of exogenous H2S donors can improve the resistance and tolerance of plants to biotic or abiotic stresses. Exogenous H2S can help plants resist abiotic stresses such as drought, waterlogging, heavy metals, salinity, extreme temperatures, and Fusarium head blight by enhancing the antioxidant capacity, osmotic adjustment capacity, and photosynthetic capacity of plants. It can be said that H2S plays a very important role in the whole growth and development process of plants and in stress conditions.

[0003] Currently, when exploring the effects of exogenous H2S on organisms, the selection of exogenous H2S donors is important. The most commonly used H2S donor is sodium hydrosulfide (NaHS). After sodium hydrosulfide dissolves in water, a large amount of H2S gas can be produced, and the reaction is very rapid and intense. Therefore, during experimental operations, a high-concentration NaHS stock solution is often first prepared and stored in a closed container. When in use, the stock solution is diluted. However, as a donor of H2S, this method often cannot accurately control the H2S concentration. In addition, high-concentration H2S often has a toxic effect on organisms, resulting in contradictory experimental results and poor experimental repeatability. At the same time, the NaHS solution needs to be repeatedly prepared to ensure the concentration, which is easy to cause waste. During field experiments, due to the unstable environment, the experimental results often cannot be applied to actual production. Currently, a variety of H2S sustained-release agents developed in the medical field are applied to plant research and agriculture, and the cost is relatively high. Therefore, it has become an urgent task to invent an H2S controlled-release agent to meet the application requirements of scientific experiments and agricultural production. Summary of the Invention

[0004] The technical problem to be solved by the present invention is how to improve the release performance of the H2S donor.

[0005] The present invention solves the above technical problems by the following technical means:

[0006] A temperature-responsive polymer nanocomposite hydrogen sulfide sustained-release agent, which includes a nanomaterial core and a coating layer coated on the nanomaterial core; the raw materials of the nanomaterial core include nanomaterials with photothermal effects, clay, sodium hydrosulfide, H2S initiator, and binder, and the mass ratio of the clay, nanomaterials with photothermal effects, sodium hydrosulfide, and H2S initiator is 1-2:1-2:2-3:4-6; the raw materials of the coating layer include alcohol-soluble polymer and amino silicone oil.

[0007] The present invention provides a temperature-responsive polymer nanocomposite hydrogen sulfide sustained-release agent with stable performance and controllable quality. It uses nanomaterials with photothermal effects and clay as the nanomaterial skeleton. The clay is distributed on the surface of the nanomaterials with photothermal effects and in the pore structure of the nanomaterials with photothermal effects. Sodium hydrosulfide (NaHS) is used as the H2S release source. Sodium hydrosulfide and the H2S initiator are adsorbed in the nanomaterial skeleton and bonded by a binder to form a nanomaterial core. Alcohol-soluble polymer and amino silicone oil are used as coating materials. The alcohol-soluble polymer and amino silicone oil are sequentially coated on the nanomaterial core to form a coating layer to obtain the sustained-release agent; temperature is the activation molecule of the nanomaterials, which solves the defects that the release rate of the H2S donor cannot be controlled, the release concentration of the donor is not easy to be determined, and the utilization rate is not high.

[0008] Preferably, the nanomaterial with photothermal effect is one or a mixture of more than one of metal nanoparticles, semiconductor nanomaterials, carbon-based nanomaterials, metal-organic framework materials (MOFs), and mesoporous silica, and it is a nanostructured material with a porous honeycomb-like structure.

[0009] Preferably, the metal nanoparticles are one or a mixture of more than one of gold nanoparticles, silver nanoparticles, and Fe3O4 nanoparticles.

[0010] Preferably, the semiconductor nanomaterial is cadmium selenide nanowires.

[0011] Preferably, the carbon-based nanomaterials are one or a mixture of more than one of biochar BioC, graphene, and carbon nanotubes.

[0012] Preferably, the nanomaterial with photothermal effect is biochar.

[0013] Preferably, the clay is one or a mixture of more than one of attapulgite ATP, halloysite, and kaolin that can form a nano-network structure.

[0014] Preferably, the H2S initiator is one or a mixture of more than one of sodium dihydrogen phosphate, ammonium bicarbonate, barium bicarbonate, and calcium bicarbonate, and it is an H2S initiator that produces water in-situ.

[0015] Preferably, the binder is one or a mixture of more than one of polyvinylpyrrolidone (PVP), polyvinyl alcohol, and chitosan.

[0016] Preferably, the alcohol-soluble polymer is one or a mixture of two of ethyl cellulose and carboxyethyl cellulose.

[0017] Preferably, for the temperature-responsive polymer nanocomposite hydrogen sulfide sustained-release agent, the nanomaterial with photothermal effect is biochar, the clay is attapulgite, the H2S initiator is a mixture of ammonium bicarbonate and sodium dihydrogen phosphate, the binder is polyvinylpyrrolidone, and the alcohol-soluble polymer is ethyl cellulose; it uses biochar and attapulgite as the nanomaterial skeleton, sodium hydrosulfide as the H2S release source, ammonium bicarbonate and sodium dihydrogen phosphate as the H2S initiator, polyvinylpyrrolidone as the binder, and ethyl cellulose and amino silicone oil as the coating materials.

[0018] Preferably, PVP serves as the binder, sustained-release agent, and enhancer for the coating adhesion force simultaneously.

[0019] Preferably, the dosage of the amino silicone oil can wrap the material formed by the nanomaterial with photothermal effect, clay, sodium hydrosulfide, H2S initiator, binder, and alcohol-soluble polymer.

[0020] Preferably, the mass ratio of the clay to the alcohol-soluble polymer is 1-2:3-4; the mass of the binder is 6% of the mass of the clay; the dosage ratio of the amino silicone oil to the clay is 1-3 ml:2 g.

[0021] The present invention also provides a method for preparing the temperature-responsive polymer nanocomposite hydrogen sulfide sustained-release agent, comprising the following steps:

[0022] S1. Mix the clay, the nanomaterial with photothermal effect, sodium hydrosulfide, and the H2S initiator in a sufficient mass ratio to obtain a mixture;

[0023] S2. Mix the mixture in S1 with the alcoholic solution of the binder and dry;

[0024] S3. Immerse the material obtained in S2 in the alcoholic solution of the alcohol-soluble polymer and dry;

[0025] S4. Drop the amino silicone oil on the surface of the material obtained in S3 until the surface of the material is completely covered, and obtain the temperature-responsive polymer nanocomposite hydrogen sulfide sustained-release agent after drying.

[0026] Preferably, the alcoholic solution of the binder is a 2% alcoholic solution of the binder prepared with absolute ethanol as the solvent; the alcoholic solution of the alcohol-soluble polymer is an alcohol-soluble polymer alcoholic solution with a mass fraction of 4-6% prepared using absolute ethanol as the solvent.

[0027] Preferably, the mass ratio of the mixture obtained in S1 to the alcoholic solution of the binder is 6-8:1-3.

[0028] Preferably, the mass ratio of the NaH2PO4 to the NH4HCO3 is 3-4:1-2.

[0029] Preferably, in the preparation process of the alcoholic solution of the binder and the alcoholic solution of the alcohol-soluble polymer, a step of ultrasonic treatment is included. The power of the ultrasonic treatment is 300-500 W, the time is 2-4 h, and during the ultrasonic treatment, the alarm temperature of the mixed solution is set to 26-28 °C.

[0030] Preferably, in S3, the immersion time is 1-3 min.

[0031] Preferably, in S4, after dropping the amino silicone oil until the surface of the material is completely covered for 1-3 min, it is dried.

[0032] The present invention also provides an application of the temperature-responsive polymer nanocomposite hydrogen sulfide sustained-release agent in promoting plant growth and development and / or improving plant drought stress resistance. When in use, different doses are selected according to needs, placed in different temperature environments, and the release of H2S is controlled.

[0033] The advantages of the present invention are as follows:

[0034] (1) It ensures a stable release rate of the H2S donor and has excellent temperature-responsive controlled release performance;

[0035] (2) The costs of the components in the product are low, and the product has good economic potential;

[0036] (3) The components in the product have good biosafety. All the components in the product are common pesticide components and are not likely to cause environmental pollution;

[0037] (4) The efficiency of the product is improved during actual use. Brief Description of the Drawings

[0038] Figure 1 Detection of the photothermal potential of biochar BioC in Example 1 of the present invention;

[0039] Figure 2 Scanning electron microscope images of ATP and BioC used in Example 1 of the present invention at different scales;

[0040] Figure 3 Cross-sectional scanning electron microscope images of ACSPES prepared in Example 1 of the present invention at different scales (a: cross-sectional view of ACSPES; b: cross-sectional view of ACSPES after treatment at 40 °C for 60 min);

[0041] Figure 4 Surface morphology images of the ACSPES material prepared in Example 1 of the present invention at different scales and surface morphology images of the ACSPES material at different temperatures (a, b, c: ACSPES; d: surface morphology of ACSPES at 40 °C; e: surface morphology of ACSPES at 60 °C; f: surface morphology of ACSPES at 80 °C);

[0042] Figure 5 Element spatial distribution diagram of EDS energy spectrum analysis of the ACSPES material prepared in Example 1 of the present invention;

[0043] Figure 6 Fourier infrared spectrum diagram of ACSPES prepared in Example 1 of the present invention;

[0044] Figure 7 H2S release curves of ACSPES prepared in Example 1 of the present invention at different temperatures;

[0045] Figure 8 Growth conditions of wheat seedlings under different treatments. Detailed Embodiments

[0046] To make the objectives, 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 embodiments of the present invention. Apparently, the described embodiments are part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0047] The test materials, reagents, etc. used in the following embodiments can be obtained from commercial channels without special instructions.

[0048] For those not specifying specific technologies or conditions in the embodiments, they can all be carried out according to the technologies or conditions described in the literature in the field or according to the product specifications.

[0049] The following-mentioned BioC is purchased from Wuhan Kaidi Electric Power Co., Ltd.

[0050] Example 1

[0051] 1) Photothermal performance measurement of BioC: 0.1 g or 0.05 g of BioC was used to prepare 1.25 mL of BioC suspension with pure water as the solvent for preparing the BioC suspension. A 2-mL centrifuge tube containing 1.25 mL of BioC suspension was placed on a photothermal imaging platform (Feichuke, Shanghai) for analysis. A 2-mL centrifuge tube containing 1.25 mL of pure water was used as a control. The light power density of the infrared laser emitter (Yuanming Laser Technology, Ningbo) was 1500 Mw / cm 2 Under this condition, the temperature of the BioC suspension was recorded every 40 μS. The results are as Figure 1 shown. The temperature of the BioC suspension containing 0.1 g of BioC and 0.05 g of BioC increased significantly over time, while the temperature of the WATER group containing only pure water in the control did not increase significantly, indicating that the biochar has good photothermal performance.

[0052] 2) Prepare an ethyl cellulose (EC) alcohol solution with a mass fraction of 5% using anhydrous ethanol as a solvent. Vortex and mix thoroughly, then ultrasonicate for 3 h for later use. Prepare a polyvinylpyrrolidone (PVP) alcohol solution with a mass fraction of 2% using anhydrous ethanol as a solvent. Vortex and mix thoroughly, then ultrasonicate for 3 h for later use. Grind sodium hydrosulfide (NaHS) from flakes into powder using a grinding machine for later use. Weigh 2 g of adenosine triphosphate (ATP), 2 g of biotin (BioC), 4 g of NaHS (powder), 6 g of sodium dihydrogen phosphate (NaH2PO4), and 2 g of ammonium bicarbonate (NH4HCO3) respectively, and mix them thoroughly to obtain an ATP@BioC@NaHS@NaH2PO4@NH4HCO3 mixture. Drop the prepared PVP alcohol solution with a mass fraction of 2% into the obtained mixture, with the mass ratio of the mixture to the PVP alcohol solution being 8:3. After thorough mixing, evenly place it on a weighing paper and air-dry at room temperature. Further soak the dried material in the EC alcohol solution with a mass fraction of 5% for 1 min, and then air-dry. Among them, the mass ratio of EC in the EC alcohol solution to clay ATP is 3:1. Drop 1 mL of amino silicone oil (ASO) onto the surface of the material until the surface of the material is completely covered. After 1 min, use filter paper to absorb the excess ASO on the surface, and then air-dry to obtain the material ATP@BioC@NaHS@PVP@NH4HCO3@NaH2PO4@EC@ASO, that is, the finished material ACSPES. The air-drying is carried out in a fume hood at a temperature not exceeding 22°C; the power of the ultrasonication is 300 W, and during the ultrasonication process, ensure that the alarm temperature of the mixed solution is set at 28°C.

[0053] Example 2

[0054] The release of H2S from the synthetic material ACSPES was measured using a portable H2S detector Gas Detector - B1010 - H2S. The release of H2S was measured at 20°C and 40°C for 15 min, 30 min, 60 min, 180 min, 300 min, and 420 min respectively ( Figure 7 ).

[0055] Example 3

[0056] Select Bainong 207 wheat seeds with uniform grain size, plump and healthy. Immerse them in a sodium hypochlorite solution with a mass fraction of 5% for 2 min, and then rinse them repeatedly with double-distilled water 6 times. Place the wheat seeds in a clean petri dish (diameter 150 mm), add pure water and culture for 12 h, then place them in a 4°C refrigerator for 6 h to make the wheat seeds germinate uniformly. Lay 6 layers of filter paper flat in a clean petri dish, add pure water until the filter paper is soaked. Select wheat seeds with consistent radicle emergence, place them evenly on the filter paper with the abdomen facing down (50 seeds / dish), and place them in a light incubator (100 μmol m -2 s -1, cultured at 25 °C under a 16 h light / 8 h dark cycle, and 20 mL of pure water was injected daily with a pipette to keep the filter paper moist. When the first leaf of the wheat seedlings grew to 4 - 5 cm, the wheat seedlings were transplanted back into a black plastic box (sized 14×9×5 cm) containing vermiculite and nutrient soil in a volume ratio of 1:1 for light soil cultivation. When the wheat seedlings grew to the two-leaf and one-heart stage, wheat seedlings with consistent growth were selected and divided into 4 groups for soil cultivation in a closed cultivation box (sized 14×9×5 cm): (1) Control group (CK): Cultured with 1 / 2 Hoagland nutrient solution + foliar spraying of pure water (i.e., irrigating the soil with 1 / 2 Hoagland nutrient solution and spraying pure water on the leaves for cultivation); (2) Drought stress (PEG): Cultured with 1 / 2 Hoagland nutrient solution + 20% PEG-6000 (w / v) (i.e., preparing a 20% PEG-6000 (w / v) solution with 1 / 2 Hoagland nutrient solution and then irrigating the soil with it for cultivation); (3) Drought stress (PH): Cultured with 1 / 2 Hoagland nutrient solution + 20% PEG-6000 (w / v) + foliar spraying of pure water (i.e., preparing a 20% PEG-6000 (w / v) solution with 1 / 2 Hoagland nutrient solution, irrigating the soil with it, and spraying pure water on the leaves for cultivation); (4) Drought stress + H2S group (PS): Cultured with 1 / 2 Hoagland nutrient solution + 20% PEG-6000 (w / v) + foliar spraying of pure water + applying 4 g of ACSPES on the soil surface (i.e., preparing a 20% PEG-6000 (w / v) solution with 1 / 2 Hoagland nutrient solution, irrigating the soil with it, spraying pure water on the leaves, and applying ACSPES on the soil surface for cultivation), and irradiating the ACSPES material with ordinary near-infrared light (Nirl-O), lamp diameter 125 mm, power 150 W, wave number 700 - 5000 nm, 20 cm above the box for 1 h daily; among them, during the cultivation process, 250 mL of the solution was applied each time and directly irrigated into the soil, and irrigation was carried out every two days from the start to the end of the experiment. After 7 days, the growth status of the wheat was as Figure 7 . From the above results, it can be seen that ACSPES significantly improved the ability of wheat seedlings to resist drought stress.

[0057] Experimental results:

[0058] As shown in the thermal imaging analysis Figure 1 shows, BioC has good photothermal properties. At a light power density of 1500 Mw / cm 2 , the temperature of 0.05 g of BioC can rise by 51.1 °C within 10 min; at a light power density of 1500 Mw / cm 2Under the light power density, the heat of 0.1 g of BioC can rise by 60.2 °C within 10 min. This result proves that ACSPES with BioC as the nano - material skeleton has potential photothermal controlled - release performance, that is, through the photothermal effect of biochar excited by infrared light, its temperature rises significantly, enabling materials containing biochar and released depending on the temperature rise to be controlled by light.

[0059] The ACSPES prepared in Example 1 was characterized. The surface morphological structure and EDS energy spectrum analysis of the material were carried out using GeminiSEM 500 Schottky field emission and SU8020 field emission scanning electron microscopes ( Figures 2 - 5 ), and Fourier transform infrared spectroscopy (FTIR) was measured using Thermo Scientific Nicolet iS5 ( Figure 6 ); The structure of ATP is clear in the SEM images ( Figure 2 (a), (b)), with a length of about 0.5 - 2 μm, having an obvious nanorod - like structure. A relatively obvious nano - network structure is formed between individual rods of ATP. BioC has an obvious multi - porous structure, showing a porous honeycomb - like shape ( Figure 2 (c), (d)). The physical structures of ATP and BioC determine their relatively large specific surface areas, indicating that they have good adsorption properties and the potential as a polymer nano - sustained - release material skeleton.

[0060] As Figure 3 , the nano - shaped network formed by ATP is distributed on the surface of BioC and in the pore structure of BioC. NaHS, NaH2PO4 (hydrate), and NH4HCO3 are adsorbed in the nano - skeleton jointly formed by ATP and BioC. NaH2PO4 and NH4HCO3 are used as initiators for the release of H2S from NaHS in the material. PVP is added to the system as a multifunctional additive such as a coupling agent, binder, sustained - release agent, and enhancer for coating adhesion. The material is successively coated on the surface by EC and ASO to form a polymer nano - composite sustained - release material ACSPES ( Figure 4 a, b). The role of the coating is to both isolate water in the air from reacting with NH4HCO3 and NaHS, and at the same time hinder the release of H2S from ACSPES. When ACSPES is placed at room temperature for 48 h, the surface structure of the ACSPES nano - material is good ( Figure 4 a, b, c). However, when ACSPES is treated at different temperatures for 1 h, the pores on the surface coating increase with the increase in temperature. The surface coating of ACSPES at 80 °C has completely become a honeycomb network shape, which is because a large amount of CO2 and H2S gas generated inside ACSPES breaks through the outer surface coating at high temperature ( Figure 4 d, e, f). As Figure 5As shown, a large amount of Al element, Mg element and C element are evenly distributed in the EDS element spatial distribution map. This result indicates that ATP and BioC have been successfully compounded in the ACSPES material system; S element, P element and N element are evenly distributed in the ACSPES material in the EDS element spatial distribution map. This result indicates that NaHS, NaH2PO4 and NH4HCO3 have been successfully distributed in the nanostructure network formed by ATP and BioC and bonded together by PVP. As Figure 6 , the FTIR results show that there is an absorption peak at 469 cm -1 , which is the bending vibration of Si-O-Si in ATP; the peak at 1096.46 cm -1 corresponds to the absorption peak of C-O-C in BioC. This result indicates that ATP and BioC have been successfully compounded in the ACSPES material system; the absorption peak at 2963.29 cm -1 corresponds to the C=O stretching vibration of PVP; the absorption peak at 1619.43 cm -1 is considered to be the peak of the C-N stretching vibration of ASO, which indicates that ASO has been successfully coated on the surface of the ACSPES material; the absorption peak at 1020.84 cm -1 is the C=S stretching vibration, which indicates that NaHS has been successfully loaded into the ACSPES material system. As Figure 7 shown, the release of H2S by 10 g of ACSPES material at 20 °C and 40 °C was investigated. At 20 °C, the ACSPES material released less H2S and the concentration was low. In the three measurements within 1 h, the portable H2S measuring instrument did not measure the release of H2S gas. As the temperature increased, the release efficiency of H2S by the ACSPES material increased. As Figure 7 shown, at 40 °C, the release of H2S gas by the ACSPES material can be effectively controlled. The highest concentration of H2S gas reached 124 ppm, and a pungent smell of H2S gas accompanied the release. Figure 8 The results show that ACSPES significantly improved the ability of wheat seedlings to resist drought stress morphologically.

[0061] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A temperature-responsive polymer nanocomposite hydrogen sulfide slow-release agent, characterized in that: It comprises a nano material core and a coating layer coated on the nano material core; the raw materials of the nano material core comprise nano material with photothermal effect, clay, sodium hydrosulfide, H2S initiator, and adhesive, and the mass ratio of the clay, the nano material with photothermal effect, sodium hydrosulfide, and H2S initiator is 1-2:1-2:2-3:4-6; the raw materials of the coating layer comprise alcohol-soluble high molecular polymer and amino silicone oil.

2. The temperature-responsive polymeric nanocomposite hydrogen sulfide sustained-release agent according to claim 1, wherein: The nanomaterial with photothermal effect is a mixture of one or more of metal nanoparticles, semiconductor nanomaterials, carbon-based nanomaterials, metal-organic framework materials, and mesoporous silica.

3. The temperature-responsive polymer nanocomposite hydrogen sulfide sustained-release agent according to claim 1, wherein: The clay is a mixture of one or more of attapulgite, halloysite and kaolin.

4. The temperature-responsive polymer nanocomposite hydrogen sulfide sustained-release agent according to claim 1, wherein: The H2S initiator is a mixture of one or more of sodium dihydrogen phosphate, ammonium bicarbonate, barium bicarbonate, and calcium bicarbonate.

5. The temperature-responsive polymer nanocomposite hydrogen sulfide sustained-release agent according to claim 1, wherein: The adhesive is a mixture of one or more of polyvinyl pyrrolidone, polyvinyl alcohol or chitosan.

6. The temperature-responsive polymeric nanocomposite hydrogen sulfide sustained-release agent according to claim 1, wherein: The alcohol-soluble high molecular polymer is ethyl cellulose or carboxyethyl cellulose or a mixture of the two.

7. The temperature-responsive polymeric nanocomposite hydrogen sulfide sustained-release agent according to any one of claims 1-6, characterized in that: The nano material with photothermal effect is biochar, the clay is attapulgite, the H2S initiator is a mixture of ammonium bicarbonate and sodium dihydrogen phosphate, the adhesive is polyvinyl pyrrolidone, and the alcohol-soluble high molecular polymer is ethyl cellulose.

8. The temperature-responsive polymeric nanocomposite hydrogen sulfide sustained-release agent according to any one of claims 1-6, characterized in that: The mass ratio of the clay to the alcohol-soluble high molecular polymer is 1-2:3-4; the mass of the adhesive is 6% of the mass of the clay; and the dosage ratio of the amino silicone oil to the clay is 1-3 ml:2 g.

9. A preparation method of a temperature-responsive polymeric nanocomposite hydrogen sulfide slow-release agent as described in any one of claims 1-8, characterized in that: The following steps are involved: S1. Fully mixing clay, nanomaterials with photothermal effect, sodium hydrosulfide, and H2S initiator according to mass ratio to obtain a mixture; S2, mixing the mixture in S1 with the binder alcohol solution and drying; S3, soaking the material obtained in S2 in an alcohol solution of an alcohol-soluble high molecular polymer, and drying; S4, dripping amino silicone oil on the surface of the material obtained in S3 until the surface of the material is completely covered, and drying to obtain the temperature-responsive polymer nanocomposite hydrogen sulfide sustained-release agent.

10. Use of the temperature-responsive polymer nanocomposite hydrogen sulfide slow-release agent according to any one of claims 1 to 8 in promoting plant growth and development and / or improving plant resistance to drought stress.

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