A superhydrophobic photothermal anti-icing coating material based on biochar and its preparation method

Abstract

This invention relates to the field of coating materials technology, specifically to a superhydrophobic photothermal anti-icing coating material based on biochar and its preparation method. The preparation method of the superhydrophobic photothermal anti-icing coating material includes: firstly modifying biochar with potassium hydroxide to obtain first modified biochar; secondly modifying the first modified biochar with hydrogen to obtain second modified biochar; mixing and dissolving the second modified biochar with a sulfur source and a molybdenum source, followed by heat treatment to obtain MoS2-loaded modified biochar; and mixing the MoS2-loaded modified biochar with a binder to obtain the superhydrophobic photothermal anti-icing coating material. This invention aims to solve the problems of high energy consumption and maintenance costs, long construction cycles, and short de-icing time associated with traditional de-icing methods for wind turbine blades.

Description

Technical Field

[0001] This invention relates to the field of coating materials technology, and more specifically, to a superhydrophobic photothermal anti-icing coating material based on biochar and its preparation method. Background Technology

[0002] In cold regions or during winter, wind turbine blades are prone to icing due to low temperatures, rain, snow, and other weather conditions, which can severely affect power generation efficiency and even threaten equipment safety. Currently, taking wind turbine blades as an example, traditional de-icing methods are mainly active de-icing, such as manual de-icing, electrothermal de-icing, gas-thermal de-icing, and chemical de-icing. Although these methods have achieved certain results in preventing and removing icing, they still have limitations such as high energy consumption and maintenance costs, long construction cycles, and short de-icing time. Summary of the Invention

[0003] The technical problem solved by this invention is that traditional de-icing methods for wind turbine blades have high energy consumption and maintenance costs, long construction cycles, and short de-icing time.

[0004] To solve or partially solve the above problems, as a first aspect, the present invention provides a method for preparing a superhydrophobic photothermal anti-icing coating material based on biochar, comprising: The biochar was modified with potassium hydroxide to obtain the first modified biochar. The first modified biochar was subjected to a second modification treatment using hydrogen gas to obtain the second modified biochar. The second modified biochar was mixed and dissolved with a sulfur source and a molybdenum source and then subjected to heat treatment to obtain MoS2-supported modified biochar. The modified biochar loaded with MoS2 was mixed with a binder to obtain the superhydrophobic photothermal anti-icing coating material.

[0005] Optionally, the primary modification treatment of biochar using solid potassium hydroxide includes: The potassium hydroxide and biochar are mixed and then heated to a first set temperature at a first heating rate under an inert gas atmosphere for a heat treatment.

[0006] Optionally, the first set temperature ranges from 700 to 800°C, the first heating rate ranges from 10 to 15°C / min, and the duration of the heat treatment ranges from 1 to 2 hours.

[0007] Optionally, the secondary modification treatment of the first modified biochar using hydrogen includes: In a mixed gas atmosphere of hydrogen and inert gas, the first modified biochar is heated to a second set temperature at a second heating rate for secondary heat treatment.

[0008] Optionally, the second set temperature ranges from 400 to 500°C, the second heating rate ranges from 10 to 15°C / min, and the time range of the secondary heat treatment is 2 to 3 hours.

[0009] Optionally, in the mixture of hydrogen and inert gas, the volume percentage of hydrogen ranges from 10% to 20%.

[0010] Optionally, the sulfur source is thioacetamide, and the molybdenum source is MoO3.

[0011] Optionally, the step of mixing and dissolving the second modified biochar with a sulfur source and a molybdenum source, followed by heat treatment to obtain MoS2-supported modified biochar includes: The second modified biochar is mixed and dissolved with the thioacetamide, the MoO3 and urea to obtain a mixed solution. The mixed solution is then heat-treated to obtain the MoS2-supported modified biochar.

[0012] Optionally, the temperature range for heat treatment of the mixed solution is 200 to 250°C, and the heat treatment time is 20 to 24 hours.

[0013] As a second aspect, the present invention also provides a superhydrophobic photothermal anti-icing coating material based on biochar, wherein the superhydrophobic photothermal anti-icing coating material is prepared by the preparation method of the superhydrophobic photothermal anti-icing coating material based on biochar as described in the first aspect.

[0014] The beneficial effects of this invention compared to related technologies include at least the following: The superhydrophobic photothermal anti-icing coating material in this embodiment of the invention uses biochar as the base material, and modifies the biochar sequentially with potassium hydroxide and hydrogen. Potassium hydroxide induces a rich microporous structure within the biochar, increasing surface irregularity and thus surface roughness, resulting in improved specific surface area and pore volume, but also introducing hydrophilic groups. Hydrogen modification introduces hydrophobic hydrogen atoms, reducing the content of N, O, and other heteroatoms on the biochar surface. The repair effect of hydrogen atoms on the carbon structure reduces defects in the biochar, making the crystal structure more complete and ordered, and enhancing stability. Under high-temperature conditions, hydrogen molecules react with oxygen-containing functional groups, initiating the breaking and reduction of chemical bonds, thereby reducing the proportion of CO, C=O, and other chemical bonds and hydrophilic functional groups. This further reduces the oxygen-to-carbon ratio of the biochar, effectively inhibiting water molecule adhesion to its surface and reducing ice bonding strength.

[0015] Based on modified biochar, this invention further utilizes MoS2 particles with photothermal effects to load the modified biochar, thereby enhancing the coating's light absorption capacity. The photothermal effect of MoS2 refers to its physical property of efficiently converting light energy into heat energy after absorption, thus conducting heat to the interior of the ice layer. This effectively improves the coating's photothermal conversion capacity, achieving proactive and efficient de-icing of the coating itself. This addresses the problems of high energy consumption and maintenance costs, long construction cycles, and short de-icing time associated with traditional de-icing methods. Attached Figure Description

[0016] Figure 1 This is a flowchart illustrating the preparation method of the superhydrophobic photothermal anti-icing coating material according to an embodiment of the present invention; Figure 2 Comparison of the surface microstructures of the corn stalk biochar coating (CC), the first modified biochar coating (KCC), the second modified biochar coating (HCC), and the superhydrophobic photothermal anti-icing coating (HCC / MoS2) in Example 1 of the present invention; Figure 3 This is a schematic diagram showing the contact angle and bond strength measurements of the HCC / MoS2 coating in Example 1 of the present invention. Figure 4 This is a schematic diagram of the icing process of the blade sections in Embodiment 1 of the present invention, which are uncoated and respectively have HCC coating and HCC / MoS2 coating. Figure 5 In Embodiment 1 of the present invention, the coating is uncoated, and the coatings are HCC and HCC / MoS2 respectively, at 1 W / cm 2 Schematic diagram of material surface temperature change under light intensity; Figure 6 This is a schematic diagram showing the change in icing area of ​​uncoated blade sections with HCC coating and HCC / MoS2 coating respectively under different angles of attack for 1 to 5 minutes when they iced. Figure 7 The lift-to-drag ratio (C) of the uncoated blade sections and the blade sections with HCC coating and HCC / MoS2 coating respectively in Embodiment 1 of the present invention after icing at different angles of attack is given. l / C D (Diagram showing the changes) Detailed Implementation

[0017] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below.

[0018] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit this application. The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to"; the term "based on" means "at least partially based on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments"; and the term "optionally" means "optional embodiments". Definitions of other terms will be given in the description below. It should be noted that the concepts of "first," "second," etc., mentioned in this invention are used to distinguish different objects, not to describe a specific order or hierarchy. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0019] The comprehensive utilization of biomass waste can reduce dependence on non-renewable resources. Converting biomass waste into bio-based materials enables high-value resource utilization, reduces energy loss, and promotes the development of a circular economy. Taking corn stalks as an example, traditional incineration of agricultural waste can severely impact the environment and human health. Pyrolysis of this agricultural waste into biochar provides a physical basis for constructing superhydrophobic surfaces due to its porous and rough characteristics. Furthermore, some dark-colored biochar can efficiently absorb sunlight and convert it into heat energy, achieving active de-icing. Therefore, combining it with anti-icing coatings for wind turbine blades can prevent resource waste, achieve energy complementarity, and ensure energy security.

[0020] This invention provides a method for preparing a superhydrophobic photothermal anti-icing coating material based on biochar, referring to... Figure 1 As shown, it includes the following steps: S1: The biochar was modified with potassium hydroxide to obtain the first modified biochar. S2: The first modified biochar is subjected to a second modification treatment using hydrogen to obtain the second modified biochar; S3: The second modified biochar was mixed and dissolved with a sulfur source and a molybdenum source and then subjected to heat treatment to obtain MoS2-supported modified biochar. S4: MoS2-loaded modified biochar is mixed with a binder to obtain a superhydrophobic photothermal anti-icing coating material.

[0021] The superhydrophobic photothermal anti-icing coating material in this embodiment of the invention uses biochar as the base material, and modifies the biochar sequentially with potassium hydroxide and hydrogen. Potassium hydroxide induces a rich microporous structure within the biochar, increasing surface irregularity and thus surface roughness, resulting in improved specific surface area and pore volume, but also introducing hydrophilic groups. Hydrogen modification introduces hydrophobic hydrogen atoms, reducing the content of N, O, and other heteroatoms on the biochar surface. The repair effect of hydrogen atoms on the carbon structure reduces defects in the biochar, making the crystal structure more complete and ordered, and enhancing stability. Under high-temperature conditions, hydrogen molecules react with oxygen-containing functional groups, initiating the breaking and reduction of chemical bonds, thereby reducing the proportion of CO, C=O, and other chemical bonds and hydrophilic functional groups. This further reduces the oxygen-to-carbon ratio of the biochar, effectively inhibiting water molecule adhesion to its surface and reducing ice bonding strength.

[0022] Based on modified biochar, this embodiment of the invention further utilizes MoS2 particles with photothermal effect to load the modified biochar, thereby enhancing the light absorption capacity of the coating. The photothermal effect of MoS2 refers to its physical property of efficiently converting light energy into heat energy after absorbing light energy, thus conducting heat to the interior of the ice layer, effectively improving the photothermal conversion capacity of the coating, and realizing the coating's own active and efficient de-icing.

[0023] Furthermore, the present invention utilizes KOH solid and hydrogen to modify biochar, which can also regulate the loading effect of MoS2. Specifically, firstly, potassium hydroxide reacts with carbon at high temperature to produce etching, which greatly increases the specific surface area of ​​biochar and creates a rich porous structure. This porous structure provides a large adhesion area and physical anchoring points for subsequent loading of molybdenum disulfide. Hydrogen reacts at high temperature to remove oxygen-containing functional groups on the surface of biochar, reducing the proportion of polar functional groups and the surface free energy of the material, increasing the hydrophobicity of the material. It can also further regulate the pore distribution and surface roughness of biochar through pyrolysis and reconstruction of the surface structure. This reducing surface is more conducive to the uniform distribution and strong interfacial bonding of molybdenum disulfide. Therefore, when these two modifications are combined, biochar becomes a three-dimensional carrier with high surface area, rich porosity, and suitable surface chemistry. This effectively prevents the aggregation of molybdenum disulfide nanosheets, exposes more active edge sites, and promotes rapid electron transfer at the interface, thereby significantly improving the loading and dispersibility of molybdenum disulfide.

[0024] In some optional embodiments, in step S1 above, biochar can be obtained from corn stalks through pyrolysis and carbonization. Corn stalks, as an important agricultural waste, are subject to serious environmental and human health consequences from traditional incineration. Combining this with research on anti-icing coatings can prevent resource waste and achieve energy complementarity in different forms, ensuring energy security. Specifically, corn stalks can be purified, pulverized, and then purged with argon gas for 30 minutes. The corn stalk powder is then carbonized using a tubular furnace and a slow pyrolysis method. After carbonization, the powder is washed with anhydrous ethanol and ultrapure water until neutral, then dried in an oven to constant weight. After removal, it is ground, sieved, dried, and stored to obtain biochar.

[0025] In some optional embodiments, step S1 above, when modifying biochar with potassium hydroxide solid, specifically includes: mixing potassium hydroxide solid with biochar, and then performing a heat treatment at a first heating rate to a first set temperature under an inert gas atmosphere. The inert gas atmosphere can be nitrogen, argon, etc., the first set temperature ranges from 700 to 800°C, the first heating rate ranges from 10 to 15°C / min, the heat treatment time is 1 to 2 hours, and the mass ratio of potassium hydroxide solid to biochar can be (1 to 2):1. It should be noted that after the first modification pyrolysis is completed, the first modified biochar is washed sequentially with anhydrous ethanol, hydrochloric acid, and ultrapure water until neutral, then placed in an oven and dried to constant weight. After removal, it is ground, sieved, and dried for storage.

[0026] During a modified pyrolysis process, KOH strongly etched the carbon framework under high temperature conditions, generating an ultra-high specific surface area and abundant pores. The huge specific surface area and abundant pores provided a massive number of sites for the growth and attachment of MoS2 nanosheets, preventing their aggregation. At the same time, oxygen-containing functional groups were introduced, some forming -OH, -COOH and other groups, increasing the surface reactive sites.

[0027] In some optional embodiments, step S2 above, when using hydrogen to perform a secondary modification treatment on the first modified biochar, specifically includes: heating the first modified biochar to a second set temperature at a second heating rate in a mixed gas atmosphere of hydrogen and inert gas, performing a secondary heat treatment to obtain the second modified biochar. The second set temperature ranges from 400 to 500°C, and a slow heating rate is also used, which can be 10 to 15°C / min. The modification time for the secondary heat treatment ranges from 2 to 3 hours. Further, in the mixed gas of hydrogen and inert gas, the volume percentage of hydrogen ranges from 10% to 20%.

[0028] During the secondary modification process, by introducing inert gases (such as N2 and Ar) as diluents and protective gases, the concentration of hydrogen can be precisely controlled within a safe range, and air can be completely eliminated. In addition, by adjusting the ratio of hydrogen to inert gas, the effective concentration (partial pressure) of hydrogen can be precisely controlled, thereby regulating the rate and extent of the reduction reaction and avoiding excessive gasification or structural damage to biochar due to excessively high hydrogen concentration or too fast reaction.

[0029] In some optional embodiments, in step S3 above, the sulfur source is thioacetamide and the molybdenum source is MoO3. The MoS2 loading process specifically includes: mixing and dissolving the second modified biochar with thioacetamide, MoO3, and urea to obtain a mixed solution; heat-treating the mixed solution; and then cooling, washing, and drying to obtain MoS2-loaded modified biochar. Specifically, the temperature range for heat treatment of the mixed solution is 200 to 250°C, and the heat treatment time is 20 to 24 hours.

[0030] In this embodiment of the invention, biochar is mixed with a molybdenum source and a sulfur source in water and heated in a sealed container. Under high temperature and pressure, MoS2 nucleates and grows in situ on the surface of the biochar. The modified biochar has a high specific surface area and abundant pores. These pores can limit the excessive growth and stacking of MoS2 nanosheets, allowing them to exist in a smaller form with more exposed edge active sites. Furthermore, the edge sulfur atoms of MoS2 may form CS bonds or C-Mo bonds with carbon atoms or defect sites on the biochar surface, achieving stronger chemical connections and promoting interfacial electron transport.

[0031] In some optional embodiments, in step S4 above, the binder can be selected from PVDF, epoxy resin, silicone resin, fluorocarbon resin, and polyurethane, etc., and the mixing mass ratio of MoS2-loaded modified biochar to binder can be 1:(2 to 3). In addition, an appropriate amount of dispersant (such as N-methylpyrrolidone) can be added to make the mixture uniformly dispersed.

[0032] It should be noted that the superhydrophobic photothermal anti-icing coating material in this embodiment of the invention can be directly sprayed onto wind turbine blades using a spray gun, and then cured in a vacuum drying oven at 60 to 100°C for 2 to 8 hours to form a coating. It should be understood that the application scenarios of the superhydrophobic photothermal anti-icing coating material are not limited to wind turbine blades, but can also be extended to any other structural surface with anti-icing requirements, such as aircraft winglets.

[0033] Another embodiment of the present invention provides a superhydrophobic photothermal anti-icing coating material based on biochar, which is prepared by the preparation method of the superhydrophobic photothermal anti-icing coating material based on biochar as described in the above embodiments.

[0034] The present invention will be described in detail below through specific embodiments: Example 1 This embodiment uses the following steps to prepare the superhydrophobic photothermal anti-icing coating material: (1) After removing impurities and crushing the corn stalks, place them in a tube furnace and introduce argon gas for 30 min. Heat the tube furnace at a rate of 10℃ / min and pyrolyze at a temperature of 550℃ for 2 h. After carbonization, wash with anhydrous ethanol and ultrapure water until neutral, then place in an oven at 110℃ to dry to constant weight. After removal, grind through a 100-mesh sieve and dry and store to obtain corn stalk biochar (CC).

[0035] (2) Potassium hydroxide and corn straw biochar were mixed at a mass ratio of 1.5:1 and placed in a tube furnace. The mixture was heated to 750℃ at a heating rate of 10℃ / min under an argon atmosphere and pyrolyzed for 2 hours. After pyrolysis, the pyrolysis product was washed with anhydrous ethanol, 0.1 mol / L hydrochloric acid and ultrapure water until neutral. Then it was dried in an oven at 110℃ until constant weight, ground through a 100-mesh sieve and dried for storage to obtain the first modified biochar (KCC).

[0036] (3) The first modified biochar was placed in a mixed gas atmosphere of hydrogen and argon (10% hydrogen, 90% argon) for secondary modification treatment. The modification time was set to 2.7h, the heating rate was 10℃ / min, and the modification temperature was set to 466℃ to obtain the second modified biochar (HCC).

[0037] (4) 15 mg of the second modified biochar was mixed with 35 mg of thioacetamide, 30 mg of MoO3, and 300 mg of urea and dissolved in 15 ml of ultrapure water and 25 ml of anhydrous ethanol. The mixture was stirred in a magnetic stirrer for 1 h to ensure uniform dispersion. The mixture was then added to a 50 mL small high-pressure reactor and reacted at 200 °C for 24 h. After the high-pressure reactor cooled to room temperature, the sample was removed and washed with water and alcohol using a vacuum filter until the sample was neutral. After washing, the sample was placed in a vacuum drying oven and dried to constant weight. The temperature of the vacuum drying oven was set to 40 °C to obtain MoS2-loaded modified biochar (HCC / MoS2).

[0038] (5) Add MoS2-loaded modified biochar and 7% PVDF binder (mass ratio 1:2) to a 10mL beaker, then add a few drops of N-methylpyrrolidone (NMP), and stir with a magnetic stirrer for 30 min to disperse the mixture evenly, to obtain a superhydrophobic photothermal anti-icing coating material.

[0039] For comparative analysis, the corn stalk biochar (CC), the first modified biochar (KCC), and the second modified biochar (HCC) in this embodiment were also mixed with 7% PVDF binder to obtain the corresponding coating materials.

[0040] In this embodiment, the CC, KCC, HCC and HCC / MoS2 coating materials were respectively sprayed onto a 100mm long wind turbine blade model using a spray gun, and then cured in an 80℃ vacuum drying oven for 6 hours to form the corresponding coatings.

[0041] Figure 2 This image shows a comparison of the surface microstructures of the corn stalk biochar coating (CC), the first modified biochar coating (KCC), the second modified biochar coating (HCC), and the superhydrophobic photothermal anti-icing coating (HCC / MoS2) in this embodiment. Figure 2 As can be seen, compared with the intermediate product, the HCC / MoS2 coating exhibits a petal-like structure with curved, thin-sheet characteristics. This special microstructure helps to improve the geometric structure effect at the gas-liquid-solid three-phase interface, forming a "lotus leaf effect". Under the obstruction of these microstructures, water droplets have difficulty fully contacting the material surface and thus slide off quickly under the action of gravity. Therefore, it helps to improve the hydrophobic properties of the material, prevent ice adhesion, and reduce the possibility of icing.

[0042] Figure 3 This diagram illustrates the contact angle and bond strength measurements of the HCC / MoS2 coating in this embodiment. The contact angle (CA) of the HCC / MoS2 coating in this embodiment is 161.01°, and the bond strength is 48.36 kPa. In the hydrophobicity test, water droplets on the coating surface are nearly spherical. When the water droplets contact the coating, they adhere to the injection needle without sticking. After the needle is removed, the water droplets leave with the needle and do not wet the coating, demonstrating its superhydrophobicity.

[0043] Figure 4 This diagram illustrates the icing process of blade sections without coating, and those with HCC coating and HCC / MoS2 coating, respectively, in this embodiment. Figure 4 It can be seen that water droplets appeared on the blade sections without coating and with HCC coating at 20s, while some water droplets appeared on the surface of the HCC / MoS2 coating at 40s. By 60s, the HCC / MoS2 coating was covered by a water film, indicating that the interaction force between its surface and water molecules was relatively small, thus reducing the speed at which water droplets formed a water film on the coating surface. During the period from 60s to 90s, although icing occurred at the leading edge of the blade section, most of the scattered droplets remained unfrozen. This proves that in the initial stage of the experiment, the superhydrophobic properties of the HCC / MoS2 coating can delay droplet adhesion and inhibit droplet condensation. However, during the period from 90s to 120s, after a large number of water droplets covered the coating surface and formed a water film, the icing on the blade section gradually increased, and its anti-icing performance decreased sharply.

[0044] Figure 5 In this embodiment, the coating is uncoated, and the coatings are HCC and HCC / MoS2 respectively, at 1 W / cm2 A schematic diagram illustrating the surface temperature change of a material under varying light intensity. From... Figure 5 As can be seen, the equilibrium temperature of the HCC / MoS2 coating is 17.5℃ higher than that of the HCC coating, indicating that the MoS2 loading with photothermal properties can effectively improve the photothermal conversion performance of the material. Especially in the visible and near-infrared spectral range, its excellent photothermal conversion performance can maintain good light absorption capacity under different conditions, thereby promoting a rapid rise in the surface temperature of the material.

[0045] Figure 6 This diagram illustrates the changes in icing area over 1 to 5 minutes at different angles of attack for blade sections without coating, with HCC coating, and with HCC / MoS2 coating, respectively. The angle of attack refers to the angle between the combined velocity of the incoming flow (the resultant velocity of wind speed and rotational speed) and the airfoil chord line. Changes in the angle of attack directly alter the impact angle and position between the blade leading edge and the supercooled water droplets in the incoming flow. Figure 6 As can be seen, with the increase of icing time, the icing area of ​​the HCC / MoS2 coating is significantly smaller than that of the uncoated and HCC coatings, indicating that the HCC / MoS2 coating in this embodiment can reduce the growth of icing area under different angles of attack and play a good anti-icing role.

[0046] Computational Fluid Dynamics (CFD) was used to perform fluid calculations on two-dimensional airfoils and three-dimensional vertical axis wind turbine blades before and after icing, in order to analyze the effect of different coatings on the aerodynamic performance of the blades. Figure 7 The lift-to-drag ratio (C) of the uncoated blade sections and the blade sections with HCC coating and HCC / MoS2 coating respectively after icing at different angles of attack in this embodiment is shown. l / C D ) Change diagram, from Figure 7 It can be seen that under different angles of attack (6°, 12°, 18°), the lift-to-drag ratio of the uncoated blade section after 5 minutes of icing is reduced by 39.39%, 33.27%, and 28.42% respectively compared to 1 minute. This indicates that icing increases the roughness of the blade surface, leading to reduced lift, increased drag, and a lower lift-to-drag ratio, thus causing a decrease in the wind turbine's efficiency. However, when the icing time is 5 minutes, the lift-to-drag ratio of the HCC / MoS2 coated blade section increases by 40.83%, 24.09%, and 21.29% respectively compared to the uncoated section under different angles of attack. This shows that the nanosheet structure of the HCC / MoS2 coating can reduce icing on the blade surface, slow down the deterioration of the lift-to-drag ratio, and thus improve the aerodynamic performance of the icing blade.

[0047] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A method for preparing a superhydrophobic photothermal anti-icing coating material based on biochar, characterized in that, include: The biochar was modified with potassium hydroxide to obtain the first modified biochar. The first modified biochar was subjected to a second modification treatment using hydrogen gas to obtain the second modified biochar. The second modified biochar was mixed and dissolved with a sulfur source and a molybdenum source and then subjected to heat treatment to obtain MoS2-supported modified biochar. The modified biochar loaded with MoS2 was mixed with a binder to obtain the superhydrophobic photothermal anti-icing coating material.

2. The method for preparing the superhydrophobic photothermal anti-icing coating material based on biochar according to claim 1, characterized in that, The primary modification treatment of biochar using solid potassium hydroxide includes: The potassium hydroxide and biochar are mixed and then heated to a first set temperature at a first heating rate under an inert gas atmosphere for a heat treatment.

3. The method for preparing the superhydrophobic photothermal anti-icing coating material based on biochar according to claim 2, characterized in that, The first set temperature ranges from 700 to 800°C, the first heating rate ranges from 10 to 15°C / min, and the duration of the heat treatment ranges from 1 to 2 hours.

4. The method for preparing the superhydrophobic photothermal anti-icing coating material based on biochar according to claim 1, characterized in that, The secondary modification treatment of the first modified biochar using hydrogen includes: In a mixed gas atmosphere of hydrogen and inert gas, the first modified biochar is heated to a second set temperature at a second heating rate for secondary heat treatment.

5. The method for preparing the superhydrophobic photothermal anti-icing coating material based on biochar according to claim 4, characterized in that, The second set temperature ranges from 400 to 500°C, the second heating rate ranges from 10 to 15°C / min, and the time range of the secondary heat treatment is 2 to 3 hours.

6. The method for preparing the superhydrophobic photothermal anti-icing coating material based on biochar according to claim 4, characterized in that, In the mixture of hydrogen and inert gas, the volume percentage of hydrogen ranges from 10% to 20%.

7. The method for preparing the superhydrophobic photothermal anti-icing coating material based on biochar according to claim 1, characterized in that, The sulfur source is thioacetamide, and the molybdenum source is MoO3.

8. The method for preparing the superhydrophobic photothermal anti-icing coating material based on biochar according to claim 7, characterized in that, The step of mixing and dissolving the second modified biochar with a sulfur source and a molybdenum source, followed by heat treatment to obtain MoS2-supported modified biochar includes: The second modified biochar is mixed and dissolved with the thioacetamide, the MoO3 and urea to obtain a mixed solution. The mixed solution is then heat-treated to obtain the MoS2-supported modified biochar.

9. The method for preparing the superhydrophobic photothermal anti-icing coating material based on biochar according to claim 8, characterized in that, The temperature range for heat treatment of the mixed solution is 200 to 250°C, and the heat treatment time is 20 to 24 hours.

10. A superhydrophobic, photothermal, and anti-icing coating material based on biochar, characterized in that, The superhydrophobic photothermal anti-icing coating material is prepared using the preparation method of biochar-based superhydrophobic photothermal anti-icing coating material as described in any one of claims 1 to 9.

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