Modified copper sulfide and preparation method and application thereof

Abstract

The invention discloses modified copper sulphide and a preparation method and application thereof.The modified copper sulphide comprises a carrier MIL-101-NH2 and copper sulphide loaded on the carrier and is of a flower-shaped structure, and the preparation method comprises the steps that 1, MIL-101-NH2 powder is added into a solvent to obtain stable dispersion liquid; and adding a copper source and a sulfur source, uniformly mixing, and heating for reaction to obtain the modified copper sulfide. The carrier MIL-101-NH2 is introduced into the copper sulfide to obtain the flower-like modified copper sulfide, so that the photo-thermal conversion performance is improved, and the flower-like modified copper sulfide has excellent antibacterial efficiency on plant fungi under the irradiation of near-infrared light.

Description

Technical Field

[0001] This invention relates to copper sulfide, and more particularly to a modified copper sulfide, its preparation method, and its application. Background Technology

[0002] The use of chemical pesticides is currently the main means of controlling plant diseases. However, long-term application not only leads to pesticide resistance in diseases but also negatively impacts plant growth and development. Furthermore, the excessive and large-scale application of chemical pesticides causes serious environmental pollution, threatens the safety of non-target organisms, and affects human health through the food chain. Therefore, developing safe, low-toxicity, highly efficient, and environmentally friendly fungicides and methods is currently an important research direction. In recent years, with the rapid development of nanotechnology, novel pesticide systems based on nanomaterials have shown broad application prospects in the field of agricultural disease control. However, current technologies mainly focus on delivering pesticides via nanocarriers to construct controlled-release nanopesticides, with limited research on directly utilizing nanomaterials to control plant diseases.

[0003] Traditional copper-containing fungicides have advantages such as broad-spectrum bactericidal activity and low price, and have been widely used in the field of plant disease control. Currently registered products include copper hydroxide, copper oxychloride, copper acetate, and copper sulfate. However, they pose a high risk of phytotoxicity, poor compatibility, limited action, and high environmental risk. Nano-copper sulfide (CuS) is a novel fungicide with excellent bactericidal properties and good biocompatibility. It has been extensively studied in biomedicine (such as anti-cancer, antibacterial infection, and skin damage repair) and food preservation (Li et al. Copper sulfide nanoparticle-carrageenan films for packaging application. Food Hydrocolloids, 2020, 109, 106094; Chan et al. Recent Advances in Copper Sulfide Nanoparticles for Phototherapy of Bacterial Infections and Cancer. Nanomedicine, 2023, 18, 2185-2204.). Currently, the application of nano-copper sulfide in the pesticide field is relatively limited. Summary of the Invention

[0004] Objectives of the Invention: The first objective of this invention is to provide a modified copper sulfide that improves photothermal conversion performance, thereby enhancing the effect of killing plant fungi; the second objective of this invention is to provide a method for preparing the modified copper sulfide; and the third objective of this invention is to provide the application of the modified copper sulfide in inhibiting plant fungi.

[0005] Technical solution: The modified copper sulfide of the present invention includes a carrier MIL-101-NH2 and copper sulfide loaded on the carrier, exhibiting a flower-like structure.

[0006] Preferably, the mass ratio of copper sulfide to MIL-101-NH2 is (1:0.5) to (1:4). This ratio affects the final synthesized morphology and the adhesion of the copper sulfide nanomaterials to MIL-101-NH2; a mass ratio of 1:1 yields the best synthesis results. The mass of copper sulfide is a theoretical value calculated based on the mass of the copper source. With an excess of sulfur source, the copper source can generally be almost entirely converted into copper sulfide.

[0007] Preferably, the modified copper sulfide has a size of 150~250 nm.

[0008] The method for preparing modified copper sulfide according to the present invention includes the following steps:

[0009] (1) Add MIL-101-NH2 powder to a solvent to obtain a stable dispersion;

[0010] (2) Add copper source and sulfur source to the above dispersion, mix evenly, heat to react, and obtain modified copper sulfide.

[0011] Preferably, in step (1), the solvent is sterile water.

[0012] Preferably, in step (2), the reaction temperature is 45~100℃; preferably, the reaction time is 20~90 min.

[0013] Preferably, the copper source is copper chloride dihydrate and the sulfur source is thioacetamide.

[0014] Preferably, the molar ratio of copper chloride dihydrate to thioacetamide is (1:1) to (1:4). The amount of copper provided by copper chloride dihydrate and sulfur provided by thioacetamide affects the synthesis of copper sulfide nanomaterials in the solvent. The optimal synthesis effect is achieved when the molar ratio of copper to sulfur in the solvent is 1:2.

[0015] The application of the modified copper sulfide described in this invention in inhibiting plant fungi.

[0016] Preferably, the fungus is *Botrytis cinerea* (kiwifruit soft rot), *Alternaria alternata* (tobacco red spot disease), *Botrytis cinerea* (grape white rot), or *Botrytis cinerea* (blueberry gray mold).

[0017] Invention Mechanism:

[0018] This invention utilizes metal-organic frameworks (MOFs) as templates to synthesize morphology-controllable modified copper sulfide nanomaterials. Among them, MIL-101-NH2 possesses a large specific surface area and abundant pores, and its framework surface has amino groups that support copper ions (Cu). 2 + It has strong coordination and adsorption capabilities, which is beneficial for copper ions (Cu). 2+ Sulfur ions (S) accumulate on the surface and near the pores of MIL-101-NH2 particles. When the sulfur source (thioacetamide) slowly decomposes, it generates sulfur ions (S). 2- In MIL-101-NH2, CuS nucleation occurs preferentially and densely on the MOF surface, rather than in a homogeneous manner in solution. The porous structure of MIL-101-NH2 physically restricts the growth direction of CuS nuclei, inhibiting their free growth into spherical shapes. Therefore, CuS is more likely to grow preferentially along a certain crystal plane, forming nanosheets. The initial CuS nanosheets formed on the MIL-101-NH2 surface have high surface energy. To reduce the system energy, these nascent nanosheets self-assemble, overlapping and fusing with each other, ultimately constructing a stable three-dimensional hierarchical structure—a flower-like microsphere.

[0019] This invention patent utilizes the high photothermal conversion efficiency of flower-shaped copper sulfide to effectively kill plant pathogens through photothermal therapy, representing a green, environmentally friendly, safe, and effective new method. Specifically, sunlight contains abundant near-infrared light, which can be used to promote the killing of plant pathogens by flower-shaped copper sulfide, saving energy. Compared with traditional copper-based pesticides, using flower-shaped copper sulfide not only effectively reduces the amount of pesticide used but also enhances adhesion and coverage to plant surfaces through its unique flower-like structure, improving the pesticide's retention at the target site, thereby effectively extending the effective period and reducing environmental runoff. Therefore, this technology provides a new approach for developing highly efficient, low-residue, and environmentally friendly green pesticides, and is expected to achieve significant applications in the field of agricultural disease control.

[0020] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: (1) By introducing the template MIL-101-NH2 into copper sulfide, flower-shaped modified copper sulfide is obtained, which improves the photothermal conversion performance. It can efficiently convert light energy into heat energy under near-infrared light irradiation, causing local high temperature, thereby achieving the effect of effectively killing plant fungi; (2) Flower-shaped modified copper sulfide has the excellent characteristics of good product stability, wide range of applications, high efficiency, low environmental pollution, simple operation, and high economic benefits; (3) The preparation process is simple and easy to industrialize; (4) The modified copper sulfide of the present invention has excellent antibacterial efficiency against plant fungi under near-infrared light irradiation, which can reduce the amount of agent used. Attached Figure Description

[0021] Figure 1Scanning electron microscope images of MIL-101-NH2 and modified copper sulfide prepared in Example 1 (image a: MIL-101-NH2, image b: modified copper sulfide).

[0022] Figure 2 Fourier transform infrared spectra of the samples prepared in Example 1, Comparative Example 1, and Comparative Example 2;

[0023] Figure 3 X-ray diffraction patterns of the samples prepared in Example 1, Comparative Example 1, and Comparative Example 2;

[0024] Figure 4 The samples prepared for Example 1, Comparative Example 1, and Comparative Example 2 were compared with water in near-infrared light (808 nm, 1.5 W / cm²). 2 Photothermal efficiency curve under irradiation;

[0025] Figure 5 The contact angle diagram of the modified copper sulfide prepared in Example 1 and water;

[0026] Figure 6 The images show the anti-staphylococcal effects of the samples prepared in Example 1 and Comparative Example 1 (Figure a is the control group, Figure b is the anti-staphylococcal effect of the sample prepared in Comparative Example 1 under near-infrared light irradiation, and Figure c is the anti-staphylococcal effect of the sample prepared in Example 1 under near-infrared light irradiation).

[0027] Figure 7 The images show scanning electron microscope (SEM) images of *Gymnococephalus* hyphae (image a shows hyphae of the control group, and image b shows hyphae treated with copper sulfide as prepared in Example 1). Detailed Implementation

[0028] The technical solution of the present invention will be further described below with reference to the embodiments.

[0029] Example 1

[0030] The modified copper sulfide of the present invention includes a carrier MIL-101-NH2 and copper sulfide loaded on the carrier. The molar ratio of copper source to sulfur source of copper sulfide is 1:2, and the mass ratio of carrier MIL-101-NH2 to copper sulfide (theoretical value) is 1:1.

[0031] The preparation method includes the following steps:

[0032] (1) Preparation of MIL-101-NH2 powder

[0033] Weigh 0.45 g of aminoterephthalic acid and 1.35 g of ferric chloride hexahydrate and dissolve them separately in 15 mL of N,N-dimethylamide (DMF). Sonicate the solutions until fully dissolved. Then mix the two solutions and stir for 30 min. The solution gradually turns dark brown. Pour the mixture into a 50 mL reaction vessel and place it in an oven. Set the temperature to 110 °C and react for 24 h. After the reaction, pour out the solution and wash it twice with DMF, anhydrous ethanol, and deionized water by centrifugation. Then place it in a vacuum drying oven and dry it at 45 °C. Grind the solution to obtain a brownish-red powder MIL-101-NH2.

[0034] (2) Preparation of modified copper sulfide

[0035] Weigh 96 mg of the synthesized MIL-101-NH2 powder into beaker A, add 25 ml of deionized water, and disperse it evenly. Weigh 171 mg (1 mmol) of copper chloride dihydrate and 150 mg (2 mmol) of thioacetamide into beaker B, add 25 ml of deionized water, stir evenly to allow it to react fully, then pour the solution from beaker B into beaker A and stir evenly. Place the mixture in an oil bath, set the heating temperature to 90℃, and heat for 30 min. After the reaction is complete and cooled, dialyze and centrifuge (8000 rpm, 10 min) to remove residual unreacted substances to obtain the final modified copper sulfide.

[0036] Example 2

[0037] The modified copper sulfide of the present invention includes a carrier MIL-101-NH2 and copper sulfide loaded on the carrier, wherein the molar ratio of copper source to sulfur source of copper sulfide is 1:1, and the mass ratio of carrier MIL-101-NH2 to copper sulfide (theoretical value) is 1:1.

[0038] The preparation method includes the following steps:

[0039] (1) The preparation of MIL-101-NH2 powder is the same as in Example 1.

[0040] (2) Preparation of modified copper sulfide

[0041] Weigh 96 mg of the synthesized MIL-101-NH2 powder into beaker A, add 25 ml of deionized water, and disperse it evenly. Weigh 171 mg (1 mmol) of copper chloride dihydrate and 75 mg (1 mmol) of thioacetamide into beaker B, add 25 ml of deionized water, stir evenly to allow it to react fully, then pour the solution from beaker B into beaker A and stir evenly. Place the mixture in an oil bath, set the heating temperature to 90℃, and heat for 30 min. After the reaction is complete and cooled, dialyze and centrifuge (8000 rpm, 10 min) to remove residual unreacted substances to obtain the final modified copper sulfide.

[0042] Example 3

[0043] The modified copper sulfide of the present invention includes a carrier MIL-101-NH2 and copper sulfide loaded on the carrier, wherein the molar ratio of copper source to sulfur source is 1:3, and the mass ratio of carrier MIL-101-NH2 to copper sulfide (theoretical value) is 1:1.

[0044] (1) The preparation of MIL-101-NH2 powder is the same as in Example 1.

[0045] (2) Preparation of modified copper sulfide

[0046] Weigh 96 mg of the synthesized MIL-101-NH2 powder into beaker A, add 25 ml of deionized water, and disperse it evenly. Weigh 171 mg (1 mmol) of copper chloride dihydrate and 225 mg (3 mmol) of thioacetamide into beaker B, add 25 ml of deionized water, stir evenly to allow it to react fully, then pour the solution from beaker B into beaker A and stir evenly. Place the mixture in an oil bath, set the heating temperature to 90℃, and heat for 30 min. After the reaction is complete and cooled, dialyze and centrifuge (8000 rpm, 10 min) to remove residual unreacted substances to obtain the final modified copper sulfide.

[0047] Example 4

[0048] The modified copper sulfide of the present invention includes a carrier MIL-101-NH2 and copper sulfide loaded on the carrier. The molar ratio of copper source to sulfur source of copper sulfide is 1:4, and the mass ratio of carrier MIL-101-NH2 to copper sulfide (theoretical value) is 1:1.

[0049] The preparation method includes the following steps:

[0050] (1) The preparation of MIL-101-NH2 powder is the same as in Example 1.

[0051] (2) Preparation of modified copper sulfide

[0052] Weigh 96 mg of the synthesized MIL-101-NH2 powder into beaker A, add 25 ml of deionized water, and disperse it evenly. Weigh 171 mg (1 mmol) of copper chloride dihydrate and 300 mg (4 mmol) of thioacetamide into beaker B, add 25 ml of deionized water, stir evenly to allow it to react fully, then pour the solution from beaker B into beaker A and stir evenly. Place the mixture in an oil bath, set the heating temperature to 90℃, and heat for 30 min. After the reaction is complete and cooled, dialyze and centrifuge (8000 rpm, 10 min) to remove residual unreacted substances to obtain the final modified copper sulfide.

[0053] Example 5

[0054] The modified copper sulfide of the present invention comprises a carrier MIL-101-NH2 and copper sulfide loaded on the carrier, wherein the mass ratio of the carrier MIL-101-NH2 to copper sulfide (theoretical value) is 0.5:1.

[0055] The preparation method includes the following steps:

[0056] (1) The preparation of MIL-101-NH2 powder is the same as in Example 1.

[0057] (2) Preparation of modified copper sulfide

[0058] Weigh 48 mg of the synthesized MIL-101-NH2 powder into beaker A, add 25 ml of deionized water, and disperse it evenly. Weigh 171 mg (1 mmol) of copper chloride dihydrate and 150 mg (2 mmol) of thioacetamide into beaker B, add 25 ml of deionized water, stir evenly to allow it to react fully, then pour the solution from beaker B into beaker A and stir evenly. Place the mixture in an oil bath, set the heating temperature to 90℃, and heat for 30 min. After the reaction is complete and cooled, dialyze and centrifuge (8000 rpm, 10 min) to remove residual unreacted substances to obtain the final modified copper sulfide.

[0059] Example 6

[0060] The modified copper sulfide of the present invention comprises a carrier MIL-101-NH2 and copper sulfide loaded on the carrier, wherein the mass ratio of the carrier MIL-101-NH2 and copper sulfide (theoretical value) is 2:1.

[0061] The preparation method includes the following steps:

[0062] (1) The preparation of MIL-101-NH2 powder is the same as in Example 1.

[0063] (2) Preparation of modified copper sulfide

[0064] Weigh 192 mg of the synthesized MIL-101-NH2 powder into beaker A, add 25 ml of deionized water, and disperse it evenly. Weigh 171 mg (1 mmol) of copper chloride dihydrate and 150 mg (2 mmol) of thioacetamide into beaker B, add 25 ml of deionized water, stir evenly to allow it to react completely, then pour the solution from beaker B into beaker A and stir evenly. Place the mixture in an oil bath, set the heating temperature to 90℃, and heat for 30 min. After the reaction is complete and cooled, dialyze and centrifuge (8000 rpm, 10 min) to remove residual unreacted substances to obtain the final modified copper sulfide.

[0065] Example 7

[0066] The modified copper sulfide of the present invention comprises a carrier MIL-101-NH2 and copper sulfide loaded on the carrier, wherein the mass ratio of the carrier MIL-101-NH2 to copper sulfide (theoretical value) is 4:1.

[0067] The preparation method includes the following steps:

[0068] (1) The preparation of MIL-101-NH2 powder is the same as in Example 1.

[0069] (2) Preparation of modified copper sulfide

[0070] Weigh 288 mg of the synthesized MIL-101-NH2 powder into beaker A, add 25 ml of deionized water, and disperse it evenly. Weigh 171 mg (1 mmol) of copper chloride dihydrate and 150 mg (2 mmol) of thioacetamide into beaker B, add 25 ml of deionized water, stir evenly to allow it to react completely, then pour the solution from beaker B into beaker A and stir evenly. Place the mixture in an oil bath, set the heating temperature to 90℃, and heat for 30 min. After the reaction is complete and cooled, dialyze and centrifuge (8000 rpm, 10 min) to remove residual unreacted substances and obtain the final reaction product.

[0071] Comparative Example 1

[0072] Weigh 171 mg of copper chloride dihydrate and 150 mg of thioacetamide into a beaker, add 50 ml of deionized water, stir well, place in an oil bath, set the heating temperature to 90 °C, heat for 30 min, and after the reaction is complete, dialyze to obtain copper sulfide nanoparticle samples.

[0073] Comparative Example 2

[0074] Based on Example 1, only MIL-101-NH2 powder was prepared.

[0075] Structural characterization

[0076] The structures of the metal-organic framework MIL-101-NH2 and modified copper sulfide prepared in Example 1 were characterized using scanning electron microscopy, and the results are as follows: Figure 1 As shown.

[0077] from Figure 1 As can be seen from (a), MIL-101-NH2 has an octahedral structure, which is structurally stable; from Figure 1 As can be seen in (b), after MIL-101-NH2 reacts with copper sulfide nanomaterials, modified copper sulfide is obtained. The morphology becomes flower-like, with a size of 150 nm to 250 nm. It has a larger specific surface area and better photothermal conversion efficiency.

[0078] The structures of the metal-organic framework MIL-101-NH2, modified copper sulfide, and copper sulfide nanomaterials prepared in Example 1 and Comparative Example 1 were characterized by Fourier transform infrared spectroscopy. The results are as follows: Figure 2 As shown.

[0079] Depend on Figure 2 Therefore, 622cm -1 The peak at this point is a characteristic peak caused by the stretching vibration of the Cu-S bond. The comparison shows that the copper sulfide nanomaterials were successfully combined with MIL-101-NH2, indicating successful preparation.

[0080] The structures of the metal-organic framework MIL-101-NH2, modified copper sulfide, and copper sulfide nanomaterials prepared in Example 1 and Comparative Example 1 were characterized using X-ray diffraction. The results are as follows: Figure 3 As shown.

[0081] Depend on Figure 3 It can be seen that in the XRD pattern, 2θ = 27.8°, 29.3°, 31.7°, 48°, and 59.3° correspond to the (101), (102), (103), (008), and (108) crystal planes of CuS, respectively. It can be seen from the figure that copper sulfide was successfully loaded on MIL-101-NH2.

[0082] Performance testing

[0083] 1. Material photothermal performance test

[0084] The modified copper sulfide prepared in Example 1, the copper sulfide prepared in Comparative Example 1, and the MIL-101-NH2 prepared in Comparative Example 2 were prepared into solutions with a concentration of 0.1 mg / mL. 0.5 mL of each solution was placed in three 1.5 mL centrifuge tubes, fixed at a height of 15 cm, and irradiated under an 808 nm near-infrared laser. The temperature rise of each group was observed to determine the photothermal properties of the materials. The near-infrared laser power was set to 1.5 W / cm². 2 After irradiation for 5 minutes, the temperature change of the material is as follows: Figure 4 As shown.

[0085] from Figure 4 It is evident that within 5 minutes, the temperatures of Example 1, Comparative Example 1, and Comparative Example 2 increased by 46.5℃, 20.1℃, and 3.4℃, respectively. The flower-shaped copper sulfide synthesized in Example 1 exhibits superior photothermal properties, showing a significant improvement over the 20.1℃ increase of the copper sulfide nanoparticles synthesized in Comparative Example 1. This is because the flower-shaped copper sulfide has a larger specific surface area, its structure possesses more light absorption sites, and a more efficient heat transfer interface. Therefore, for the flower-shaped copper sulfide, its complex three-dimensional structure and rough surface act as a "light trap." When light enters the gaps between the petals or irradiates the rough surface, multiple reflections and scattering occur, greatly increasing the path length of light propagation within the material. Ordinary copper sulfide, lacking such a complex structure, has relatively low light absorption efficiency.

[0086] 2. Water contact angle test

[0087] The flower-shaped copper sulfide obtained in Example 1 and water were respectively dropped onto kiwifruit leaves for contact angle testing. The changes in contact angle were observed and recorded. The contact angle test results within 8 minutes are as follows: Figure 5 As shown.

[0088] from Figure 5 It can be clearly seen that the contact angle of flower-shaped copper sulfide on kiwifruit leaves is smaller than that of water, and the contact angle of flower-shaped copper sulfide decreases at a faster rate over time. This indicates that flower-shaped copper sulfide has good leaf surface affinity and wettability, and can effectively spread and deposit on the leaf surface, achieving more efficient utilization.

[0089] 3. Antibacterial performance test

[0090] Taking *Botrytis cinerea*, the pathogen causing soft rot in kiwifruit, as an example: On a clean bench, the samples generated in Example 1 and Comparative Example 1 were added to different sterilized potato dextrose agar flasks, shaken well, and sterilized deionized water was added to prepare a culture medium with a concentration of 0.05 mg / mL. The culture medium was then quantitatively dispensed into disposable petri dishes with a diameter of 9 cm and allowed to cool and solidify. A 5 mm diameter perforator was used to punch holes at the edge of the *Botrytis cinerea* petri dish (provided by the College of Agriculture, Guizhou University). The mycelial cake was transferred to the center of the previously prepared culture medium using a mycelium extractor and sealed with sealing film. An 808 nm near-infrared laser was used to irradiate the mycelial cake at a distance of 15 cm for 10 min, with a laser power of 1.5 W / cm². 2 After irradiation, all petri dishes were placed in an incubator, and the incubation temperature was set to 28℃. The growth of *Staphylococcus aureus* was observed and recorded. The results on the 7th day after treatment are as follows: Figure 6As shown in the figure. Mycelia from the control group and experimental group were removed, SEM images were taken, and the mycelial condition was observed. The test results are as follows. Figure 7 As shown.

[0091] from Figure 6 As can be seen from the data, compared with the control group (a), at 1.5 W / cm 2 Under infrared light irradiation, the copper sulfide nanoparticles prepared in Comparative Example 1(b) showed a certain antibacterial effect with an inhibition rate of 33.8%. At the same concentration, the modified copper sulfide prepared in Example 1(c) showed a more significant antibacterial effect with an inhibition rate of 94.1%, demonstrating that the flower-shaped copper sulfide synthesized under 808 nm infrared light has a higher photothermal conversion efficiency and a better antibacterial effect.

[0092] The hyphae of *Botrytis cinerea* treated with copper sulfide in Example 1 were characterized by scanning electron microscopy, and the results are as follows: Figure 7 As shown. By Figure 7 It can be clearly seen that the mycelial surface of the control group in Figure a is smooth, while the mycelial surface of the control group in Figure b, after being treated with copper sulfide in Example 1, shows wrinkling and breakage.

[0093] To further confirm the universality of this method in controlling different plant fungi, Alternaria alternata, the pathogen of tobacco red spot disease, Cyclocarya paliurus, the pathogen of grape white rot, and Botrytis cinerea, the pathogen of blueberry gray mold (all of the above strains were provided by the College of Agriculture of Guizhou University) were selected as control targets. The operation steps were the same as those for Staphylococcus aureus. Only the effect of Example 1 was examined, and the inhibition rate against pathogens was measured on the 7th day after treatment.

[0094] The results are shown in Table 1.

[0095] Table 1

[0096] Serial Number Types of pathogens Inhibition rate 1 Staphylococcus aureus 94.1% 2 Alternaria 93.2% 3 White rot spores 96.5% 4 Botrytis cinerea 93.7%

[0097] The results showed that under near-infrared light irradiation, the flower-shaped modified copper sulfide of Example 1 effectively inhibited the growth of the aforementioned plant fungi through photothermal sterilization. This is because the flower-shaped modified copper sulfide has excellent photothermal conversion capabilities, efficiently converting light energy into heat energy, causing irreversible damage to pathogens through high temperature, thus achieving an effective sterilization effect. Unlike chemical antibacterial drugs, photothermal sterilization is non-selective, therefore it can indiscriminately destroy various pathogens and has universality.

[0098] Compared with traditional copper-based agents:

[0099] The antibacterial effects of traditional copper-based agents against Staphylococcus aureus were investigated, including Bordeaux mixture, copper oxychloride, copper sulfate, quinoline copper, and copper acetate. The experimental procedures were the same as described above, and the concentration of each agent was 0.05 mg / mL (calculated based on the active ingredient content). The effects of light exposure and lack of light exposure were also examined. The results are shown in Table 2.

[0100] Table 2

[0101]

[0102] The results showed that traditional copper-based fungicides exhibited low inhibitory effects on *Botrytis cinerea* at the same dosage, with no significant control efficacy. There was no significant difference in effect with or without near-infrared light irradiation, mainly because traditional copper-based fungicides lack photothermal effects. The flower-shaped modified copper sulfide in Example 1 also showed a low inhibition rate (23.8%) without near-infrared light irradiation, likely due to the weak bactericidal effect of copper-based fungicides at low concentrations. However, after near-infrared light irradiation, the flower-shaped modified copper sulfide in Example 1, with its excellent photothermal properties, effectively inhibited *Botrytis cinerea* (94.1%) through photothermal sterilization. This result further highlights the innovation and superiority of this invention, significantly reducing the dosage of copper-based pesticides and utilizing near-infrared light for sterilization.

Claims

1. A modified copper sulfide characterized in that, The modified copper sulfide comprises a carrier MIL-101-NH2 and copper sulfide loaded on the carrier, and presents a flower-like structure.

2. The modified copper sulfide according to claim 1, wherein, The mass ratio of the copper sulfide to the MIL-101-NH2 is (1:0.5) to (1:4).

3. The modified copper sulfide of claim 1, wherein, The size of the modified copper sulfide is 150-250 nm.

4. A method for producing the modified copper sulfide according to any one of claims 1 to 3, characterized by, The method comprises the following steps: (1) adding the MIL-101-NH2 powder into a solvent to obtain a stable dispersion liquid; (2) adding a copper source and a sulfur source into the dispersion liquid, mixing uniformly, and heating to react to obtain the modified copper sulfide.

5. The method for producing modified copper sulfide according to claim 4, characterized by, In the step (2), the reaction temperature is 45-100℃.

6. The method for producing modified copper sulfide according to claim 5, characterized by, The reaction time is 20-90 min.

7. The method of producing modified copper sulfide according to claim 4, characterized by, The copper source is copper chloride dihydrate, and the sulfur source is thioacetamide.

8. The method of producing modified copper sulfide according to claim 4, characterized by, The molar ratio of the copper chloride dihydrate to the thioacetamide is (1:1) to (1:4).

9. Application of the modified copper sulfide in any one of claims 1-3 to inhibit plant fungi.

10. Use according to claim 9, characterized in that, The fungi are Botryosphaeria dothidea, Alternaria alternata, Gliocephalum album, and Botrytis cinerea.

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