Carbon / metal hybrid material prepared from discarded medical protective clothing, method and application thereof

Abstract

The present invention discloses a carbon / metal hybrid material prepared from discarded medical protective clothing, a method thereof, and an application thereof, and belongs to the technical field of solid waste recycling and reuse. The method comprises the following steps: 1) soaking the discarded medical protective clothing in an alkaline solution, and then adding a saccharide containing a polyhydroxy structure to obtain a discarded medical protective clothing with the saccharide adhering to the surface; 2) soaking the discarded medical protective clothing with the saccharide adhering to the surface in a soluble metal salt solution, so that the metal ions coordinate and bind with the hydroxyl groups on the saccharide containing a polyhydroxy structure, and then drying the discarded medical protective clothing with the metal ions; 3) catalytically carbonizing the dried discarded medical protective clothing under an inert atmosphere to obtain a carbon / metal hybrid material. The present invention realizes the high-value recycling and reuse of solid waste, reduces environmental pollution and energy consumption; the carbon / metal hybrid material prepared with discarded medical protective clothing as raw materials has excellent electromagnetic properties and has great application potential in electromagnetic wave absorption.

Description

Technical Field

[0001] The present invention belongs to the technical field of solid waste recycling and reuse, and specifically relates to a carbon / metal hybrid material prepared from discarded medical protective clothing, a method thereof, and an application thereof. Background Art

[0002] Disposable medical protective clothing is the work uniform of medical staff, which plays a role in blocking pathogens and harmful ultrafine dust. After the disposable medical protective clothing is used, it is collected and incinerated as medical waste. The main component of disposable discarded medical protective clothing is polypropylene. From the perspective of recycling, high-temperature incineration of disposable medical protective clothing is mainly to recover heat, but toxic "dioxin" gas will be produced during the incineration process. At the same time, the "greenhouse effect" caused by large amounts of CO2 emissions seriously endangers the balance of the natural ecosystem and threatens the human living environment. There are certain achievements in the existing technology for the recycling of waste polymers and disposable medical materials. Chinese invention patent CN113651321B is a waste polymer-derived carbon and its preparation method and application. The waste polymer is crushed and mixed with sulfur powder to obtain a mixed powder; the mixed powder is then carbonized by programmed temperature increase in an inert gas to obtain waste polymer-derived carbon. This method uses waste polymers and sulfur powder, which are abundant in source and low in price, as raw materials. Through simple heat treatment, it realizes the upgrading and recycling of waste polymers into high value-added clean energy materials. The preparation process is simple and suitable for large-scale production, with ultra-high commercial and social application value. Chinese invention patent CN115043392A discloses a method for preparing porous carbon nanosheets using discarded medical disposable protective clothing. The method uses discarded medical disposable protective clothing as raw material and MgO as template. The porous carbon nanosheets are prepared by reaction in a high-pressure reactor, and the MgO template can be recycled to save costs. Therefore, the recycling and high-value reuse of discarded medical protective clothing can achieve the real meaning of "turning waste into treasure", but there is no relevant report on the use of discarded medical protective clothing to prepare electromagnetic wave absorbing materials. Summary of the Invention

[0003] The present invention provides a carbon / metal hybrid material prepared from discarded medical protective clothing, a method thereof, and an application thereof. The prepared carbon / metal hybrid material is an aggregate of a dielectric loss material (carbon material) and a magnetic loss material (elemental substances of Fe, Co, and Ni). Due to the high conductivity of the carbon material and the high magnetic permeability of the magnetic material, a synergistic effect of multiple loss mechanisms is formed, so that the carbon / metal hybrid material exhibits good electromagnetic matching, and can therefore be used as an electromagnetic wave absorption material.

[0004] The technical solution of the present invention is:

[0005] In a first aspect, the present invention provides a method for preparing a carbon / metal hybrid material from discarded medical protective clothing, comprising the following steps:

[0006] 1) soaking discarded medical protective clothing in an alkaline solution, and then adding a saccharide containing a polyhydroxy structure to obtain discarded medical protective clothing with the saccharide adhered to the surface;

[0007] 2) soaking the discarded medical protective clothing with sugars adhering to the surface in a soluble metal salt solution, so that the metal ions coordinate and bind with the hydroxyl groups on the sugars containing a polyhydroxy structure, and then drying the discarded medical protective clothing with the metal ions;

[0008] 3) The dried discarded medical protective clothing is catalytically carbonized under an inert atmosphere to obtain a carbon / metal hybrid material.

[0009] Preferably, in step 1), the polyhydroxy structure-containing sugars are monosaccharides, disaccharides and polysaccharides, preferably glucose, sucrose, maltose or fructose.

[0010] Preferably, in step 1), the alkaline solution is an aqueous ammonia solution, an aqueous sodium hydroxide solution or an aqueous potassium hydroxide solution; and the pH value of the alkaline solution is 8-12.

[0011] Preferably, in step 1), the mass ratio of discarded medical protective clothing to the saccharide containing a polyhydroxy structure is 1:0.05-1, and the soaking time is 3-5 hours.

[0012] Preferably, in step 2), the soluble metal salt is ferric nitrate, cobalt nitrate, nickel nitrate, ferric chloride, cobalt chloride, nickel chloride, ferric acetate, cobalt acetate, nickel acetate, ferric sulfate, cobalt sulfate or nickel sulfate.

[0013] Preferably, in step 2), the mass ratio of the discarded medical protective clothing with sugars adhered to the surface to the soluble metal salt is 1:0.05-0.2.

[0014] Preferably, in step 2), the drying temperature is 60-90 ° C.

[0015] Preferably, in step 3), the inert atmosphere is nitrogen or argon, the catalytic carbonization temperature is 650-850° C., and the heating rate is 5-10° C. / min.

[0016] In a second aspect, the present invention provides a carbon / metal hybrid material prepared by the above method.

[0017] In a third aspect, the present invention further provides an application of the carbon / metal hybrid material prepared by the above method, wherein the carbon / metal hybrid material is used as an electromagnetic wave absorbing material.

[0018] like Figure 1As shown, the present invention utilizes discarded medical protective clothing to prepare carbon / metal hybrid materials based on the following principles: the main component of discarded medical protective clothing is polypropylene fiber cloth, which has a hydrophobic surface and is difficult to adsorb metal ions. The surface of the protective clothing treated with an alkaline solution has a small amount of hydroxyl groups. The hydroxyl groups of the saccharide interact with the hydroxyl groups on the surface of the protective clothing through hydrogen bonding, uniformly coating the surface of the protective clothing with the saccharide. At the same time, since the saccharide contains a large number of hydroxyl groups, it can adsorb metal ions through coordination. As a result, a large number of metal ions are fixed to the surface of the polypropylene fiber cloth as a catalyst for its high-temperature carbonization, and the saccharide acts as a bridge to increase the catalyst loading. At high temperatures of 650-850°C, the polypropylene molecular chain will degrade and break into small molecular hydrocarbons. These small molecular hydrocarbons are enriched on the surface of the metal catalyst (such as iron, cobalt and nickel compounds), dehydrogenated and aromatized, and then rearranged to form carbon materials. At the same time, the metal ions react with the reducing gases (such as hydrogen, methane, propylene, etc.) generated by the degradation of polypropylene to convert into metal elements, resulting in the final collected product being a carbon / metal hybrid material. Graphitized carbon materials have good electrical conductivity, and metal particles of iron, cobalt, and nickel are magnetic. The combination of the two exhibits good electromagnetic matching properties, so the prepared carbon / metal hybrid materials are suitable for use as electromagnetic wave absorbing materials.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. The present invention utilizes recycled discarded medical protective clothing as a carbon source to prepare a carbon / metal hybrid material. The prepared carbon / metal hybrid material is an aggregate of a dielectric loss material (carbon material) and a magnetic loss material (elemental materials of Fe, Co, and Ni). Due to the high electrical conductivity of the carbon material and the high magnetic permeability of the magnetic material, a synergistic effect of multiple loss mechanisms is formed, resulting in the carbon / metal hybrid material exhibiting good electromagnetic compatibility, and thus can be used as an electromagnetic wave absorption material. Compared with directly incinerating discarded medical protective clothing to recover heat, the product prepared by the present invention has high added value, achieving a true "waste-to-treasure" transformation. Moreover, the recycling process reduces CO2 emissions and reduces environmental pollution.

[0021] 2. The present invention has the advantages of a wide range of raw material sources, simple preparation process, low processing cost, suitability for mass production, and high yield of carbon / metal hybrid materials (the highest yield is as high as 41.2%).

[0022] 3. The carbon / metal hybrid material prepared by the present invention exhibits excellent wave absorbing performance, with a minimum reflection loss of -47.66 dB (corresponding to a thickness of 3.5 mm) and a maximum effective absorption bandwidth of 6.31 GHz (corresponding to a thickness of 3.5 mm). BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1The present invention is a schematic diagram of the preparation process of binding metal ions to discarded medical protective clothing; in the figure, (1) is a saccharide with hydroxyl groups adhering to the surface of the discarded medical protective clothing, and (2) is a metal ion coordinated with the hydroxyl group and bound to the discarded medical protective clothing obtained in (1).

[0024] Figure 2 This is the XRD pattern of the carbon / metal (C / Fe) hybrid material prepared in Example 1.

[0025] Figure 3 (a) SEM image and (b) TEM image of the carbon / metal (C / Fe) hybrid material prepared in Example 1.

[0026] Figure 4 This is a reflection loss curve of the carbon / metal (C / Fe) hybrid material prepared in Example 1.

[0027] Figure 5 This is the XRD pattern of the carbon / metal (C / Co) hybrid material prepared in Example 2.

[0028] Figure 6 (a) SEM image and (b) TEM image of the carbon / metal (C / Co) hybrid material prepared in Example 2.

[0029] Figure 7 This is a reflection loss curve of the carbon / metal (C / Co) hybrid material prepared in Example 2.

[0030] Figure 8 This is the XRD pattern of the carbon / metal (C / Ni) hybrid material prepared in Example 3.

[0031] Figure 9 (a) SEM image and (b) TEM image of the carbon / metal (C / Ni) hybrid material prepared in Example 3.

[0032] Figure 10 This is a reflection loss curve of the carbon / metal (C / Ni) hybrid material prepared in Example 3. DETAILED DESCRIPTION

[0033] Example 1

[0034] The method for preparing carbon / metal (C / Fe) hybrid materials from discarded medical protective clothing is as follows:

[0035] 1) Weigh 3.00 g of discarded medical protective clothing and place it in 10 mL of sodium hydroxide solution with a pH of 8 to completely soak the discarded medical protective clothing. Soak the clothing at room temperature for 3 h. Then, add 1.50 g of glucose to the soaking solution and continue soaking for 2 h. Remove the clothing and air-dry it at room temperature to obtain discarded medical protective clothing with glucose adhered to the surface, with a mass of 4.40 g.

[0036] 2) Weigh 0.22 g of ferric nitrate and place it in 30 mL of deionized water. Stir and dissolve thoroughly. Place the discarded medical protective clothing with glucose adhered to its surface in step 1) into the ferric nitrate solution and soak for 1 hour. Then, place it in a 60°C oven until the water is completely evaporated and remove it.

[0037] 3) The surface-treated discarded medical protective clothing obtained in step 2) was placed in a porcelain boat, which was then placed in a tube furnace. The tube furnace was heated to 650°C at a rate of 10°C / min under a nitrogen atmosphere and kept warm for 2 hours. After the reaction, the tube furnace was cooled to room temperature at a rate of 5°C / min under nitrogen protection. The remaining product in the porcelain boat was the target product, carbon / metal hybrid material, with a yield of 41.2%.

[0038] The XRD pattern of the carbon / metal hybrid material prepared in this example is shown in FIG. Figure 2 As shown in the figure, obvious diffraction peaks appear at 23.7° and 44.3° of 2-Theta. Compared with the standard card (JCPDS No.89-7373), the above diffraction peaks correspond to the (002) crystal plane and (101) crystal plane of graphite carbon, respectively. Diffraction peaks appear at 44.6° and 65.1° of 2-Theta. Compared with the standard card ((JCPDS No.06-0696), the above diffraction peaks correspond to the (110) crystal plane and (200) crystal plane of elemental Fe, respectively. Therefore, it is determined that the product of this embodiment is a C / Fe hybrid material.

[0039] The morphology of the carbon / metal hybrid material prepared in this example is as follows Figure 3 As shown, the hybrid material has a flake-like stacking structure, and there are a large number of holes on the surface of the carbon sheet, which helps electromagnetic waves enter the interior of the material and promotes energy dissipation and absorption.

[0040] The reflection loss curve of the carbon / metal hybrid material prepared in this example is as follows: Figure 4 As shown in the figure, the minimum reflection loss is -45.64dB (corresponding to a thickness of 2.0mm) and the effective absorption bandwidth is 4.92GHz (corresponding to a thickness of 2.0mm), which indicates that it has excellent absorbing performance.

[0041] Example 2

[0042] The method for preparing C / Co hybrid materials from discarded medical protective clothing is as follows:

[0043] 1) Weigh 3.00 g of discarded medical protective clothing and place it in 10 ml of potassium hydroxide solution with a pH of 9 to completely soak the discarded medical protective clothing. Soak at room temperature for 4 hours. Then, add 3.00 g of sucrose to the soaking solution, stir evenly, and continue soaking for 2 hours. After removing and air-drying, the discarded medical protective clothing with sucrose adhered to the surface is obtained, with a mass of 5.90 g.

[0044] 2) Weigh 0.59 g of cobalt chloride and place it in 20 mL of deionized water. Stir and dissolve thoroughly. Place the discarded medical protective clothing with sucrose adhered to its surface in step 1) into the cobalt chloride solution, stir and soak for 1 hour, then place in a 90°C oven until the water is completely evaporated and remove.

[0045] 3) The discarded medical protective clothing obtained in step 2) was placed in a porcelain boat, which was then placed in a tube furnace. The tube furnace was heated to 750° C. at a rate of 5° C. / min under a nitrogen atmosphere and kept warm for 2 hours. After the reaction was completed, the tube furnace was cooled to room temperature at a rate of 5° C. / min under nitrogen protection. The remaining product in the porcelain boat was the target product, carbon / metal hybrid material, with a yield of 35.6%.

[0046] The XRD pattern of the carbon / metal hybrid material prepared in this example is shown in FIG. Figure 5 As shown, obvious diffraction peaks appeared at 23.6° and 44.3° of 2-Theta. Compared with the standard card (JCPDS.89-7373), it can be seen that the above diffraction peaks correspond to the (002) crystal plane and (101) crystal plane of graphite carbon, respectively. At 44.2°, 51.5° and 75.8° of 2-Theta, relatively obvious diffraction peaks appeared. Compared with the standard card (PDF#15-0806), it can be seen that the above diffraction peaks correspond to the (111) crystal plane, (200) crystal plane and (220) crystal plane of elemental Co, respectively. Therefore, it is determined that the product obtained in this example is a C / Co hybrid material.

[0047] The morphology (SEM and TEM) of the carbon / metal hybrid material prepared in this example is as follows: Figure 6 As shown, the material has a sheet structure, and there are a large number of holes on the surface of the carbon sheet, which helps electromagnetic waves enter the interior of the material and promotes energy dissipation and absorption.

[0048] The reflection loss curve of the carbon / metal hybrid material prepared in this embodiment is as follows: Figure 7 As shown, the minimum reflection loss is -42.31dB (corresponding to a thickness of 2.0mm) and the effective absorption bandwidth is 4.10GHz (corresponding to a thickness of 2.0mm), showing excellent absorbing performance.

[0049] Example 3

[0050] The method for preparing C / Ni hybrid materials from discarded medical protective clothing is as follows:

[0051] 1) Weigh 3.00 g of discarded medical protective clothing and place it in 10 ml of ammonia solution with a pH of 10 to completely soak the discarded medical protective clothing. Soak at room temperature for 5 h, then add 0.75 g of maltose to the soaking solution, stir evenly, and continue soaking for 2 h. After removing and air-drying, the discarded medical protective clothing with maltose adhered to the surface is obtained, with a mass of 3.65 g.

[0052] 2) Weigh 0.73 g of nickel sulfate and place it in 20 mL of deionized water, stirring to dissolve thoroughly. Place the discarded medical protective clothing with maltose adhered to its surface in step 1) into the nickel sulfate solution, stir evenly, soak for 1 hour, and then place in an 80°C oven until the water is completely evaporated and remove.

[0053] 3) The discarded medical protective clothing obtained in step 2) was placed in a porcelain boat, and then the porcelain boat was placed in a tube furnace. The tube furnace was heated to 850°C at a rate of 8°C / min under an argon atmosphere and kept warm for 2 hours. After the reaction was completed, the tube furnace was cooled to room temperature at a rate of 5°C / min under argon protection. The remaining product in the porcelain boat was the target product, carbon / metal hybrid material, with a yield of 39.2%.

[0054] The XRD pattern of the carbon / metal hybrid material prepared in this example is shown in FIG. Figure 8 As shown, obvious diffraction peaks appeared at 23.7° and 44.3° of 2-Theta. Compared with the standard card (JCPDS.89-7373), it can be seen that the above diffraction peaks correspond to the (002) crystal plane and (101) crystal plane of graphite carbon, respectively; diffraction peaks appeared at 44.5°, 51.8° and 76.4° of 2-Theta. Compared with the standard card (PDF#87-0712), it can be seen that the above diffraction peaks correspond to the (111) crystal plane, (200) crystal plane and (220) crystal plane of elemental Ni, respectively; thus, it was determined that the product obtained in this example was a C / Ni hybrid material.

[0055] The morphology (SEM and TEM) of the carbon / metal hybrid material prepared in this example is as follows: Figure 9 As shown, the material has a fibrous stacking structure, and TEM further observed hollow carbon nanotubes, whose good conductivity helps to increase dielectric loss and absorb electromagnetic wave energy.

[0056] The reflection loss curve of the carbon / metal hybrid material prepared in this embodiment is as follows: Figure 10 As shown, the minimum reflection loss is -47.66 dB (corresponding to a thickness of 3.5 mm) and the effective absorption bandwidth is 6.31 GHz (corresponding to a thickness of 3.5 mm), which indicates that the prepared hybrid material has excellent wave absorbing properties.

[0057] Example 4

[0058] The method for preparing carbon / metal (C / Fe) hybrid materials from discarded medical protective clothing is as follows:

[0059] 1) Weigh 3.00 g of discarded medical protective clothing and place it in 10 mL of sodium hydroxide solution with a pH of 11 to completely soak the discarded medical protective clothing. Soak the clothing at room temperature for 3 h. Then, add 0.20 g of fructose to the soaking solution and continue soaking for 2 h. Remove the clothing and air-dry it at room temperature to obtain 3.18 g of discarded medical protective clothing with fructose adhering to its surface.

[0060] 2) Weigh 0.60 g of ferric chloride and place it in 30 mL of deionized water. Stir and dissolve thoroughly. Place the discarded medical protective clothing with fructose adhering to its surface in the ferric chloride solution from step 1) and soak for 1 hour. Then, place it in a 60°C oven until the water is completely evaporated and remove it.

[0061] 3) The surface-treated discarded medical protective clothing obtained in step 2) was placed in a porcelain boat, which was then placed in a tube furnace. The tube furnace was heated to 650°C at a rate of 10°C / min under a nitrogen atmosphere and kept warm for 2 hours. After the reaction was completed, the tube furnace was cooled to room temperature at a rate of 5°C / min under nitrogen protection. The remaining product in the porcelain boat was the target product, carbon / metal hybrid material, with a yield of 36.7%.

[0062] Example 5

[0063] The method for preparing carbon / metal (C / Co) hybrid materials from discarded medical protective clothing is as follows:

[0064] 1) Weigh 3.00 g of discarded medical protective clothing and place it in 10 mL of sodium hydroxide solution with a pH of 8 to completely soak the discarded medical protective clothing. Soak the clothing at room temperature for 3 h. Then, add 1.50 g of glucose to the soaking solution and continue soaking for 2 h. Remove the clothing and air-dry it at room temperature to obtain discarded medical protective clothing with glucose adhered to the surface, with a mass of 4.40 g.

[0065] 2) Weigh 0.35 g of cobalt nitrate and place it in 30 mL of deionized water. Stir and dissolve thoroughly. Place the discarded medical protective clothing with glucose adhered to its surface in step 1) into the cobalt nitrate solution and soak for 1 hour. Then, place it in a 60°C oven until the water is completely evaporated and remove it.

[0066] 3) The surface-treated discarded medical protective clothing obtained in step 2) was placed in a porcelain boat, which was then placed in a tube furnace. The tube furnace was heated to 650°C at a rate of 10°C / min under a nitrogen atmosphere and kept warm for 2 hours. After the reaction was completed, the tube furnace was cooled to room temperature at a rate of 5°C / min under nitrogen protection. The remaining product in the porcelain boat was the target product, carbon / metal hybrid material, with a yield of 33.4%.

[0067] Example 6

[0068] The method for preparing C / Ni hybrid materials from discarded medical protective clothing is as follows:

[0069] 1) Weigh 3.00 g of discarded medical protective clothing and place it in 10 ml of potassium hydroxide solution with a pH of 9 to completely soak the discarded medical protective clothing. Soak at room temperature for 4 hours. Then, add 3.00 g of sucrose to the soaking solution, stir evenly, and continue soaking for 2 hours. After removing and air-drying, the discarded medical protective clothing with sucrose adhered to the surface is obtained, with a mass of 5.90 g.

[0070] 2) Weigh 0.59 g of nickel acetate and place it in 20 mL of deionized water. Stir and dissolve thoroughly. Place the discarded medical protective clothing with sucrose adhered to its surface in step 1) into the nickel acetate solution, stir and soak for 1 hour, then place in a 90°C oven until the water is completely evaporated and remove.

[0071] 3) The discarded medical protective clothing obtained in step 2) was placed in a porcelain boat, which was then placed in a tube furnace. The tube furnace was heated to 750° C. at a rate of 5° C. / min under a nitrogen atmosphere and kept warm for 2 hours. After the reaction was completed, the tube furnace was cooled to room temperature at a rate of 5° C. / min under nitrogen protection. The remaining product in the porcelain boat was the target product, carbon / metal hybrid material, with a yield of 38.8%.

[0072] Example 7

[0073] The method for preparing carbon / metal (C / Fe) hybrid materials from discarded medical protective clothing is as follows:

[0074] 1) Weigh 3.00 g of discarded medical protective clothing and place it in 10 mL of sodium hydroxide solution with a pH of 12 to completely soak the discarded medical protective clothing. Soak the clothing at room temperature for 3 h. Then, add 1.50 g of fructose to the soaking solution and continue soaking for 2 h. Remove the clothing and air-dry it at room temperature to obtain 4.40 g of discarded medical protective clothing with fructose adhered to its surface.

[0075] 2) Weigh 0.22 g of ferric acetate and place it in 30 mL of deionized water. Stir and dissolve thoroughly. Place the discarded medical protective clothing with fructose adhering to its surface in the ferric acetate solution from step 1) and soak for 1 hour. Then, place it in a 60°C oven until the water is completely evaporated and remove it.

[0076] 3) The surface-treated discarded medical protective clothing obtained in step 2) was placed in a porcelain boat, which was then placed in a tube furnace. The tube furnace was heated to 650°C at a rate of 10°C / min under a nitrogen atmosphere and kept warm for 2 hours. After the reaction was completed, the tube furnace was cooled to room temperature at a rate of 5°C / min under nitrogen protection. The remaining product in the porcelain boat was the target product, carbon / metal hybrid material, with a yield of 34.5%.

[0077] Example 8

[0078] The method for preparing C / Co hybrid materials from discarded medical protective clothing is as follows:

[0079] 1) Weigh 3.00 g of discarded medical protective clothing and place it in 10 ml of ammonia solution with a pH of 10 to completely soak the discarded medical protective clothing. Soak at room temperature for 5 h. Then, add 0.75 g of glucose to the soaking solution, stir evenly, and continue soaking for 2 h. Remove and air dry to obtain discarded medical protective clothing with glucose adhered to the surface, with a mass of 3.65 g.

[0080] 2) Weigh 0.73 g of cobalt sulfate and place it in 20 mL of deionized water, stirring to dissolve thoroughly. Place the discarded medical protective clothing with glucose adhered to its surface in step 1) into the cobalt sulfate solution, stir evenly, soak for 1 hour, and then place in an 80°C oven until the water is completely evaporated and remove.

[0081] 3) The discarded medical protective clothing obtained in step 2) was placed in a porcelain boat, and then the porcelain boat was placed in a tube furnace. The tube furnace was heated to 850°C at a rate of 8°C / min under an argon atmosphere and kept warm for 2 hours. After the reaction was completed, the tube furnace was cooled to room temperature at a rate of 5°C / min under argon protection. The remaining product in the porcelain boat was the target product, carbon / metal hybrid material, with a yield of 34.2%.

[0082] Example 9

[0083] The method for preparing C / Ni hybrid materials from discarded medical protective clothing is as follows:

[0084] 1) Weigh 3.00 g of discarded medical protective clothing and place it in 10 ml of ammonia solution with a pH of 10 to completely soak the discarded medical protective clothing. Soak at room temperature for 5 h. Then, add 0.75 g of sucrose to the soaking solution, stir evenly, and continue soaking for 2 h. Remove and air dry to obtain discarded medical protective clothing with sucrose adhered to the surface, with a mass of 3.65 g.

[0085] 2) Weigh 0.73 g of nickel nitrate and place it in 20 mL of deionized water. Stir and dissolve thoroughly. Place the discarded medical protective clothing with sucrose adhered to its surface in step 1) into the nickel nitrate solution, stir and soak for 1 hour, then place in an 80°C oven until the water is completely evaporated and remove.

[0086] 3) The discarded medical protective clothing obtained in step 2) was placed in a porcelain boat, and then the porcelain boat was placed in a tube furnace. The tube furnace was heated to 850°C at a rate of 8°C / min under an argon atmosphere and kept warm for 2 hours. After the reaction was completed, the tube furnace was cooled to room temperature at a rate of 5°C / min under argon protection. The remaining product in the porcelain boat was the target product, carbon / metal hybrid material, with a yield of 37.5%.

[0087] Example 10

[0088] The method for preparing C / Fe hybrid materials from discarded medical protective clothing is as follows:

[0089] 1) Weigh 3.00 g of discarded medical protective clothing and place it in 10 ml of ammonia solution with a pH of 10 to completely soak the discarded medical protective clothing. Soak at room temperature for 5 h, then add 0.75 g of maltose to the soaking solution, stir evenly, and continue soaking for 2 h. After removing and air-drying, the discarded medical protective clothing with maltose adhered to the surface is obtained, with a mass of 3.65 g.

[0090] 2) Weigh 0.73 g of ferric sulfate and place it in 20 mL of deionized water. Stir and dissolve thoroughly. Place the discarded medical protective clothing with maltose adhered to its surface in the ferric sulfate solution, stir and soak for 1 hour, then place in an 80°C oven until the water is completely evaporated and remove.

[0091] 3) The discarded medical protective clothing obtained in step 2) was placed in a porcelain boat, and then the porcelain boat was placed in a tube furnace. The tube furnace was heated to 850°C at a rate of 8°C / min under an argon atmosphere and kept warm for 2 hours. After the reaction was completed, the tube furnace was cooled to room temperature at a rate of 5°C / min under argon protection. The remaining product in the porcelain boat was the target product, carbon / metal hybrid material, with a yield of 32.5%.

[0092] Example 11

[0093] The method for preparing C / Co hybrid materials from discarded medical protective clothing is as follows:

[0094] 1) Weigh 3.00 g of discarded medical protective clothing and place it in 10 ml of potassium hydroxide solution with a pH of 9 to completely soak the discarded medical protective clothing. Soak the clothing at room temperature for 4 hours. Then, add 3.00 g of fructose to the soaking solution, stir evenly, and continue soaking for 2 hours. Remove the clothing and air dry it to obtain 5.90 g of discarded medical protective clothing with fructose adhered to its surface.

[0095] 2) Weigh 0.59 g of cobalt acetate and place it in 20 mL of deionized water. Stir and dissolve thoroughly. Place the discarded medical protective clothing with fructose adhering to its surface in step 1) into the cobalt acetate solution, stir and soak for 1 hour, then place in a 90°C oven until the water is completely evaporated and remove.

[0096] 3) The discarded medical protective clothing obtained in step 2) was placed in a porcelain boat, which was then placed in a tube furnace. The tube furnace was heated to 750° C. at a rate of 5° C. / min under a nitrogen atmosphere and kept warm for 2 hours. After the reaction was completed, the tube furnace was cooled to room temperature at a rate of 5° C. / min under nitrogen protection. The remaining product in the porcelain boat was the target product, carbon / metal hybrid material, with a yield of 31.9%.

[0097] Example 12

[0098] The method for preparing C / Ni hybrid materials from discarded medical protective clothing is as follows:

[0099] 1) Weigh 3.00 g of discarded medical protective clothing and place it in 10 ml of potassium hydroxide solution with a pH of 9 to completely soak the discarded medical protective clothing. Soak at room temperature for 4 hours. Then, add 3.00 g of sucrose to the soaking solution, stir evenly, and continue soaking for 2 hours. After removing and air-drying, the discarded medical protective clothing with sucrose adhered to the surface is obtained, with a mass of 5.90 g.

[0100] 2) Weigh 0.59 g of nickel chloride and place it in 20 mL of deionized water. Stir and dissolve thoroughly. Place the discarded medical protective clothing with sucrose adhered to its surface in step 1) into the nickel chloride solution, stir and soak for 1 hour, then place in a 90°C oven until the water is completely evaporated and remove.

[0101] 3) The discarded medical protective clothing obtained in step 2) was placed in a porcelain boat, which was then placed in a tube furnace. The tube furnace was heated to 750° C. at a rate of 5° C. / min under a nitrogen atmosphere and kept warm for 2 hours. After the reaction was completed, the tube furnace was cooled to room temperature at a rate of 5° C. / min under nitrogen protection. The remaining product in the porcelain boat was the target product, carbon / metal hybrid material, with a yield of 31.7%.

[0102] Example 13

[0103] The method for preparing carbon / metal (C / Ni) hybrid materials from discarded medical protective clothing is as follows:

[0104] 1) Weigh 3.00 g of discarded medical protective clothing and place it in 10 mL of sodium hydroxide solution with a pH of 8 to completely soak the discarded medical protective clothing. Soak the clothing at room temperature for 3 h. Then, add 1.50 g of sucrose to the soaking solution and continue soaking for 2 h. Remove the clothing and air-dry it at room temperature to obtain 4.40 g of discarded medical protective clothing with sucrose adhered to its surface.

[0105] 2) Weigh 0.22 g of nickel sulfate and place it in 30 mL of deionized water. Stir and dissolve thoroughly. Place the discarded medical protective clothing with sucrose adhered to its surface in step 1) into the nickel sulfate solution and soak for 1 hour. Then, place it in a 60°C oven until the water is completely evaporated and remove it.

[0106] 3) The surface-treated discarded medical protective clothing obtained in step 2) was placed in a porcelain boat, which was then placed in a tube furnace. The tube furnace was heated to 650°C at a rate of 10°C / min under a nitrogen atmosphere and kept warm for 2 hours. After the reaction was completed, the tube furnace was cooled to room temperature at a rate of 5°C / min under nitrogen protection. The remaining product in the porcelain boat was the target product, carbon / metal hybrid material, with a yield of 36.1%.

[0107] Example 14

[0108] The method for preparing C / Fe hybrid materials from discarded medical protective clothing is as follows:

[0109] 1) Weigh 3.00 g of discarded medical protective clothing and place it in 10 ml of ammonia solution with a pH of 10 to completely soak the discarded medical protective clothing. Soak at room temperature for 5 h. Then, add 0.75 g of glucose to the soaking solution, stir evenly, and continue soaking for 2 h. Remove and air dry to obtain discarded medical protective clothing with glucose adhered to the surface, with a mass of 3.65 g.

[0110] 2) Weigh 0.73 g of ferric chloride and place it in 20 mL of deionized water. Stir and dissolve thoroughly. Place the discarded medical protective clothing with glucose adhered to its surface in the ferric chloride solution in step 1) and stir evenly. Soak for 1 hour, then place in an 80°C oven until the water is completely evaporated and remove.

[0111] 3) The discarded medical protective clothing obtained in step 2) was placed in a porcelain boat, and then the porcelain boat was placed in a tube furnace. The tube furnace was heated to 850°C at a rate of 8°C / min under an argon atmosphere and kept warm for 2 hours. After the reaction was completed, the tube furnace was cooled to room temperature at a rate of 5°C / min under argon protection. The remaining product in the porcelain boat was the target product, carbon / metal hybrid material, with a yield of 39.3%.

[0112] Example 15

[0113] The method for preparing C / Fe hybrid materials from discarded medical protective clothing is as follows:

[0114] 1) Weigh 3.00 g of discarded medical protective clothing and place it in 10 ml of ammonia solution with a pH of 10 to completely soak the discarded medical protective clothing. Soak at room temperature for 5 h. Then, add 0.75 g of glucose to the soaking solution, stir evenly, and continue soaking for 2 h. Remove and air dry to obtain discarded medical protective clothing with glucose adhered to the surface, with a mass of 3.65 g.

[0115] 2) Weigh 0.73 g of ferric acetate and place it in 20 mL of deionized water. Stir and dissolve thoroughly. Place the discarded medical protective clothing with glucose adhered to its surface in step 1) into the ferric acetate solution, stir and soak for 1 hour, then place in an 80°C oven until the water is completely evaporated and remove.

[0116] 3) The discarded medical protective clothing obtained in step 2) was placed in a porcelain boat, and then the porcelain boat was placed in a tube furnace. The tube furnace was heated to 850°C at a rate of 8°C / min under an argon atmosphere and kept warm for 2 hours. After the reaction was completed, the tube furnace was cooled to room temperature at a rate of 5°C / min under argon protection. The remaining product in the porcelain boat was the target product, carbon / metal hybrid material, with a yield of 30.2%.

[0117] Example 16

[0118] The method for preparing C / Fe hybrid materials from discarded medical protective clothing is as follows:

[0119] 1) Weigh 3.00 g of discarded medical protective clothing and place it in 10 ml of ammonia solution with a pH of 10 to completely soak the discarded medical protective clothing. Soak at room temperature for 5 h. Then, add 0.75 g of glucose to the soaking solution, stir evenly, and continue soaking for 2 h. Remove and air dry to obtain discarded medical protective clothing with glucose adhered to the surface, with a mass of 3.65 g.

[0120] 2) Weigh 0.73 g of ferric sulfate and place it in 20 mL of deionized water. Stir and dissolve thoroughly. Place the discarded medical protective clothing with glucose adhered to its surface in the ferric sulfate solution, stir evenly, and soak for 1 hour. Then, place it in an 80°C oven until the water is completely evaporated and remove it.

[0121] 3) The discarded medical protective clothing obtained in step 2) was placed in a porcelain boat, which was then placed in a tube furnace. The tube furnace was heated to 850°C at a rate of 8°C / min under an argon atmosphere and kept warm for 2 hours. After the reaction was completed, the tube furnace was cooled to room temperature at a rate of 5°C / min under argon protection. The remaining product in the porcelain boat was the target product, carbon / metal hybrid material, with a yield of 33.7%.

[0122] Comparative Example 1

[0123] The treatment method of the discarded medical protective clothing of Comparative Example 1 is as follows:

[0124] 1) Weigh 3.00 g of discarded medical protective clothing and place it in 10 mL of sodium hydroxide solution with a pH of 8 to completely soak the discarded medical protective clothing. Soak the discarded medical protective clothing at room temperature for 3 hours, remove it and air dry it to obtain a surface-modified discarded medical protective clothing with a mass of 3.05 g;

[0125] 2) Weigh 0.70 g of ferric nitrate and place it in 30 mL of deionized water. Stir and dissolve thoroughly. Place the discarded medical protective clothing from step 1) into the ferric nitrate solution, stir evenly, and soak for 1 hour. Then, place it in a 60°C oven until the water is completely evaporated and remove it.

[0126] 3) The discarded medical protective clothing obtained in step 2) was placed in a porcelain boat, which was then placed in a tube furnace. The temperature of the tube furnace was raised to 650°C at a rate of 10°C / min under a nitrogen atmosphere and kept at this temperature for 2 hours. After the reaction was completed, the tube furnace was cooled to room temperature at a rate of 5°C / min under nitrogen protection. The remaining product in the porcelain boat was the reference product, with a yield of 4.1%.

[0127] Comparative Example 2

[0128] The treatment method of the discarded medical protective clothing of Comparative Example 2 is as follows:

[0129] 1) Weigh 3.00 g of discarded medical protective clothing and place it in 10 mL of sodium hydroxide solution with a pH of 9 to completely soak the discarded medical protective clothing. Soak the discarded medical protective clothing at room temperature for 4 hours, remove it and air dry it to obtain a surface-modified discarded medical protective clothing with a mass of 3.06 g;

[0130] 2) Weigh 0.16 g of cobalt nitrate and place it in 20 mL of deionized water, stirring to dissolve thoroughly. Place the discarded medical protective clothing from step 1) into the cobalt nitrate solution, stir evenly, soak for 1 hour, and then place it in a 90°C oven until the water is completely evaporated and remove it;

[0131] 3) The discarded medical protective clothing obtained in step 2) was placed in a porcelain boat, which was then placed in a tube furnace. The temperature of the tube furnace was raised to 750°C at a rate of 5°C / min under a nitrogen atmosphere and kept at this temperature for 2 hours. After the reaction was completed, the tube furnace was cooled to room temperature at a rate of 5°C / min under nitrogen protection. The remaining product in the porcelain boat was the reference product, with a yield of 5.3%.

[0132] Comparative Example 3

[0133] The treatment method of the discarded medical protective clothing of Comparative Example 3 is as follows:

[0134] 1) Weigh 3.00 g of discarded medical protective clothing and place it in 10 mL of sodium hydroxide solution with a pH of 10 to completely soak the discarded medical protective clothing. Soak the discarded medical protective clothing at room temperature for 5 hours, remove it and air dry it to obtain a surface-modified discarded medical protective clothing with a mass of 3.08 g;

[0135] 2) Weigh 0.616 g of nickel nitrate and place it in 20 mL of deionized water. Stir and dissolve thoroughly. Place the discarded medical protective clothing from step 1) into the nickel nitrate solution, stir evenly, soak for 1 hour, and then place in an 80°C oven until the water is completely evaporated and remove.

[0136] 3) The discarded medical protective clothing obtained in step 2) was placed in a porcelain boat, which was then placed in a tube furnace. The temperature of the tube furnace was raised to 850°C at a rate of 8°C / min under a nitrogen atmosphere and kept at this temperature for 2 hours. After the reaction was completed, the tube furnace was cooled to room temperature at a rate of 5°C / min under nitrogen protection. The remaining product in the porcelain boat was the reference product, with a yield of 5.9%.

[0137] Comparative Example 4

[0138] The treatment method of the discarded medical protective clothing of Comparative Example 4 is as follows:

[0139] 1) Weigh 3.00 g of discarded medical protective clothing and place it in 10 mL of sodium hydroxide solution with a pH of 8 to completely soak the discarded medical protective clothing. Soak the discarded medical protective clothing at room temperature for 3 hours, remove it and air dry it to obtain a surface-modified discarded medical protective clothing with a mass of 3.05 g;

[0140] 2) Weigh 0.48 g of ferric chloride and place it in 30 mL of deionized water. Stir and dissolve thoroughly. Place the discarded medical protective clothing from step 1) into the ferric chloride solution, stir evenly, and soak for 1 hour. Then, place it in a 60°C oven until the water is completely evaporated and remove it.

[0141] 3) The discarded medical protective clothing obtained in step 2) was placed in a porcelain boat, which was then placed in a tube furnace. The temperature of the tube furnace was raised to 650°C at a rate of 10°C / min under a nitrogen atmosphere and kept at this temperature for 2 hours. After the reaction was completed, the tube furnace was cooled to room temperature at a rate of 5°C / min under nitrogen protection. The remaining product in the porcelain boat was the reference product, with a yield of 5.2%.

[0142] Comparative Example 5

[0143] The treatment method of the discarded medical protective clothing of Comparative Example 5 is as follows:

[0144] 1) Weigh 3.00 g of discarded medical protective clothing and place it in 10 mL of sodium hydroxide solution with a pH of 9 to completely soak the discarded medical protective clothing. Soak the discarded medical protective clothing at room temperature for 4 hours, remove it and air dry it to obtain a surface-modified discarded medical protective clothing with a mass of 3.06 g;

[0145] 2) Weigh 0.30 g of cobalt chloride and place it in 20 mL of deionized water, stirring to dissolve thoroughly. Place the discarded medical protective clothing from step 1) into the cobalt chloride solution, stir evenly, soak for 1 hour, and then place in a 90°C oven until the water is completely evaporated and remove.

[0146] 3) The discarded medical protective clothing obtained in step 2) was placed in a porcelain boat, which was then placed in a tube furnace. The temperature of the tube furnace was raised to 750°C at a rate of 5°C / min under a nitrogen atmosphere and kept at this temperature for 2 hours. After the reaction was completed, the tube furnace was cooled to room temperature at a rate of 5°C / min under nitrogen protection. The remaining product in the porcelain boat was the reference product, with a yield of 5.6%.

[0147] Comparative Example 6

[0148] The treatment method of the discarded medical protective clothing of Comparative Example 6 is as follows:

[0149] 1) Weigh 3.00 g of discarded medical protective clothing and place it in 10 mL of sodium hydroxide solution with a pH of 9 to completely soak the discarded medical protective clothing. Soak the discarded medical protective clothing at room temperature for 4 hours, remove it and air dry it to obtain a surface-modified discarded medical protective clothing with a mass of 3.06 g;

[0150] 2) Weigh 0.30 g of nickel chloride and place it in 20 mL of deionized water. Stir and dissolve thoroughly. Place the discarded medical protective clothing from step 1) into the nickel chloride solution, stir evenly, and soak for 1 hour. Then, place it in a 90°C oven until the water is completely evaporated and remove it.

[0151] 3) The discarded medical protective clothing obtained in step 2) was placed in a porcelain boat, which was then placed in a tube furnace. The temperature of the tube furnace was raised to 750°C at a rate of 5°C / min under a nitrogen atmosphere and kept at that temperature for 2 hours. After the reaction was completed, the tube furnace was cooled to room temperature at a rate of 5°C / min under nitrogen protection. The remaining product in the porcelain boat was the reference product, with a yield of 6.6%.

[0152] Comparative Example 7

[0153] The treatment method of the discarded medical protective clothing of Comparative Example 7 is as follows:

[0154] 1) Weigh 3.00 g of discarded medical protective clothing and place it in 10 mL of sodium hydroxide solution with a pH of 8 to completely soak the discarded medical protective clothing. Soak the discarded medical protective clothing at room temperature for 3 hours, remove it and air dry it to obtain a surface-modified discarded medical protective clothing with a mass of 3.06 g;

[0155] 2) Weigh 0.16 g of ferric acetate and place it in 30 mL of deionized water. Stir and dissolve thoroughly. Place the discarded medical protective clothing from step 1) into the ferric acetate solution, stir evenly, and soak for 1 hour. Then, place it in a 60°C oven until the water is completely evaporated and remove it.

[0156] 3) The discarded medical protective clothing obtained in step 2) was placed in a porcelain boat, which was then placed in a tube furnace. The temperature of the tube furnace was raised to 650°C at a rate of 10°C / min under a nitrogen atmosphere and kept at this temperature for 2 hours. After the reaction was completed, the tube furnace was cooled to room temperature at a rate of 5°C / min under nitrogen protection. The remaining product in the porcelain boat was the reference product, with a yield of 4.5%.

[0157] Comparative Example 8

[0158] The treatment method of the discarded medical protective clothing of Comparative Example 8 is as follows:

[0159] 1) Weigh 3.00 g of discarded medical protective clothing and place it in 10 mL of sodium hydroxide solution with a pH of 9 to completely soak the discarded medical protective clothing. Soak the discarded medical protective clothing at room temperature for 4 hours, remove it and air dry it to obtain a surface-modified discarded medical protective clothing with a mass of 3.06 g;

[0160] 2) Weigh 0.30 g of cobalt acetate and place it in 20 mL of deionized water, stirring to dissolve thoroughly. Place the discarded medical protective clothing from step 1) into the cobalt acetate solution, stir evenly, soak for 1 hour, and then place in a 90°C oven until the water is completely evaporated and remove.

[0161] 3) The discarded medical protective clothing obtained in step 2) was placed in a porcelain boat, which was then placed in a tube furnace. The temperature of the tube furnace was raised to 750°C at a rate of 5°C / min under a nitrogen atmosphere and kept at this temperature for 2 hours. After the reaction was completed, the tube furnace was cooled to room temperature at a rate of 5°C / min under nitrogen protection. The remaining product in the porcelain boat was the reference product, with a yield of 5.3%.

[0162] Comparative Example 9

[0163] The treatment method of the discarded medical protective clothing of Comparative Example 9 is as follows:

[0164] 1) Weigh 3.00 g of discarded medical protective clothing and place it in 10 mL of sodium hydroxide solution with a pH of 9 to completely soak the discarded medical protective clothing. Soak the discarded medical protective clothing at room temperature for 4 hours, remove it and air dry it to obtain a surface-modified discarded medical protective clothing with a mass of 3.06 g;

[0165] 2) Weigh 0.30 g of nickel acetate and place it in 20 mL of deionized water. Stir and dissolve thoroughly. Place the discarded medical protective clothing from step 1) into the nickel acetate solution, stir evenly, and soak for 1 hour. Then, place it in a 90°C oven until the water is completely evaporated and remove it.

[0166] 3) The discarded medical protective clothing obtained in step 2) was placed in a porcelain boat, which was then placed in a tube furnace. The temperature of the tube furnace was raised to 750°C at a rate of 5°C / min under a nitrogen atmosphere and kept at this temperature for 2 hours. After the reaction was completed, the tube furnace was cooled to room temperature at a rate of 5°C / min under nitrogen protection. The remaining product in the porcelain boat was the reference product, with a yield of 6.2%.

[0167] Comparative Example 10

[0168] The treatment method of the discarded medical protective clothing of Comparative Example 10 is as follows:

[0169] 1) Weigh 3.00 g of discarded medical protective clothing and place it in 10 mL of sodium hydroxide solution with a pH of 10 to completely soak the discarded medical protective clothing. Soak the discarded medical protective clothing at room temperature for 5 hours, remove it and air dry it to obtain a surface-modified discarded medical protective clothing with a mass of 3.10 g;

[0170] 2) Weigh 0.62 g of ferric sulfate and place it in 20 mL of deionized water. Stir and dissolve thoroughly. Place the discarded medical protective clothing from step 1) into the ferric sulfate solution, stir evenly, and soak for 1 hour. Then, place it in an 80°C oven until the water is completely evaporated and remove it.

[0171] 3) The discarded medical protective clothing obtained in step 2) was placed in a porcelain boat, which was then placed in a tube furnace. The temperature of the tube furnace was raised to 850°C at a rate of 8°C / min under a nitrogen atmosphere and kept at that temperature for 2 hours. After the reaction was completed, the tube furnace was cooled to room temperature at a rate of 5°C / min under nitrogen protection. The remaining product in the porcelain boat was the reference product, with a yield of 4.7%.

[0172] Comparative Example 11

[0173] The treatment method of the discarded medical protective clothing of Comparative Example 11 is as follows:

[0174] 1) Weigh 3.00 g of discarded medical protective clothing and place it in 10 mL of sodium hydroxide solution with a pH of 10 to completely soak the discarded medical protective clothing. Soak the discarded medical protective clothing at room temperature for 5 hours, remove it and air dry it to obtain a surface-modified discarded medical protective clothing with a mass of 3.09 g;

[0175] 2) Weigh 0.62 g of cobalt sulfate and place it in 20 mL of deionized water, stirring to fully dissolve. Place the discarded medical protective clothing from step 1) into the cobalt sulfate solution, stir evenly, soak for 1 hour, and then place in an 80°C oven until the water is completely evaporated and remove.

[0176] 3) The discarded medical protective clothing obtained in step 2) was placed in a porcelain boat, which was then placed in a tube furnace. The temperature of the tube furnace was raised to 850°C at a rate of 8°C / min under a nitrogen atmosphere and kept at this temperature for 2 hours. After the reaction was completed, the tube furnace was cooled to room temperature at a rate of 5°C / min under nitrogen protection. The remaining product in the porcelain boat was the reference product, with a yield of 5.8%.

[0177] Comparative Example 12

[0178] The treatment method of the discarded medical protective clothing of Comparative Example 12 is as follows:

[0179] 1) Weigh 3.00 g of discarded medical protective clothing and place it in 10 mL of sodium hydroxide solution with a pH of 10 to completely soak the discarded medical protective clothing. Soak the discarded medical protective clothing at room temperature for 5 hours, remove it and air dry it to obtain a surface-modified discarded medical protective clothing with a mass of 3.10 g;

[0180] 2) Weigh 0.62 g of nickel sulfate and place it in 20 mL of deionized water. Stir and dissolve thoroughly. Place the discarded medical protective clothing from step 1) into the nickel sulfate solution, stir evenly, soak for 1 hour, and then place in an 80°C oven until the water is completely evaporated and remove.

[0181] 3) The discarded medical protective clothing obtained in step 2) was placed in a porcelain boat, which was then placed in a tube furnace. The temperature of the tube furnace was raised to 850°C at a rate of 8°C / min under a nitrogen atmosphere and kept at that temperature for 2 hours. After the reaction was completed, the tube furnace was cooled to room temperature at a rate of 5°C / min under nitrogen protection. The remaining product in the porcelain boat was the reference product, with a yield of 6.4%.

[0182] Comparative Example 13

[0183] The method for preparing carbon / metal (C / Fe) hybrid materials from discarded medical protective clothing is as follows:

[0184] 1) Weigh 3.00 g of discarded medical protective clothing and place it in 10 mL of pure water to completely soak the discarded medical protective clothing. Soak the clothing at room temperature for 3 h. Then, add 1.50 g of glucose to the soaking solution and continue soaking for 2 h. Remove the clothing and air-dry it at room temperature to obtain 3.20 g of glucose-modified discarded medical protective clothing.

[0185] 2) Weigh 0.16 g of ferric nitrate and place it in 30 mL of deionized water. Stir and dissolve thoroughly. Place the discarded medical protective clothing with glucose adhered to its surface in step 1) into the ferric nitrate solution and soak for 1 hour. Then, place it in a 60°C oven until the water is completely evaporated and remove it.

[0186] 3) The surface-treated discarded medical protective clothing obtained in step 2) was placed in a porcelain boat, which was then placed in a tube furnace. The tube furnace was heated to 650°C at a rate of 10°C / min under a nitrogen atmosphere and kept warm for 2 hours. After the reaction was completed, the tube furnace was cooled to room temperature at a rate of 5°C / min under nitrogen protection. The remaining product in the porcelain boat was the target product, carbon / metal hybrid material, with a yield of 12.8%.

[0187] Electromagnetic absorption performance was measured using a vector network analyzer (VNA) in the 2-18 GHz frequency range. The test involved weighing a carbon / metal hybrid material and solid paraffin wax and mixing them at 60°C (the carbon / metal hybrid material content was fixed at 30 wt%). The mixture was then placed into a mold and pressed into a ring with an outer diameter of 7.00 mm and an inner diameter of 3.04 mm. The complex dielectric constant ε (ε = ε' - jε") and the complex magnetic permeability μ (μ = μ' - jμ") were then measured. According to transmission line theory, the reflection loss (RL, in dB), which represents the electromagnetic wave absorption capacity, can be calculated using the following formula:

[0188] RL=20log 10 |(Z in -Z0) / (Z in +Z0)|

[0189]

[0190] Where: Z in is the input impedance of the electromagnetic wave; Z0 is the free space wave impedance; d is the sample thickness (mm); c is the speed of light (m / s); f is the electromagnetic wave frequency (GHz); j is the imaginary unit. The minimum reflection loss (RL) is determined by the lowest point of the reflection loss curve. min , unit is dB); the frequency band where the RL value is lower than -10dB is called the effective absorption bandwidth (EAB, unit is GHz), which can be calculated by the intersection of the reflection loss curve and -10dB.

[0191] The electromagnetic absorption performance of the products prepared in Examples 1-16 and Comparative Examples 1-13 was tested, and the results are shown in Table 1.

[0192] Table 1 Test results of sugar and soluble metal salt composition, product yield and electromagnetic absorption performance in Examples 1-16 and Comparative Examples 1-13

[0193]

[0194]

[0195] It can be seen from Examples 1-16 and Comparative Examples 1-12 in Table 1 that when only soluble metal salts are used to treat waste medical protective clothing, the yield of the obtained carbon / metal hybrid material is very low, all below 7.0 wt%; after adding sugars to modify the surface of the discarded medical protective clothing, the adsorption of the soluble metal salt on the surface of the protective clothing is increased and the uniform dispersion of the soluble metal salt on the surface of the protective clothing is improved, thereby greatly improving the yield of the carbon / metal hybrid material, the yield is more than 30 wt%, and even the yield of Example 3 reaches 41.2 wt%, achieving high-efficiency recycling of discarded medical protective clothing.

[0196] In addition, it can be seen from Examples 1-16 in Table 1 that the carbon / metal hybrid materials prepared by combining sugars and soluble metal salts exhibit excellent wave absorption performance. The carbon / metal hybrid material prepared in Example 3 has a minimum reflection loss of -47.66 dB (thickness 3.5 mm) and an effective absorption bandwidth of 6.31 GHz (thickness 3.5 mm). However, the carbon / metal hybrid materials prepared in Comparative Examples 1-12 have poor wave absorption performance (the minimum reflection loss is greater than -10 dB and does not reach the EAB statistical interval). This indicates that sugars play a key role in the process of soluble metal salt-catalyzed carbonization of protective clothing, and the resulting product has good electromagnetic matching and thus has excellent wave absorption performance.

[0197] At the same time, it can be seen from Comparative Example 13 in Table 1 that since the main component of the discarded medical protective clothing is polypropylene fiber cloth, the surface is hydrophobic and it is difficult to adsorb metal ions. If it is not pretreated with an alkaline solution to make its surface have a small amount of hydroxyl groups, the amount of sugar adsorbed on the surface of the fiber cloth will be greatly reduced, and the subsequent metal ion loading amount coordinated with it will be small, which ultimately leads to a low carbonization rate and poor wave absorption performance.

[0198] Although the present invention has been described in detail with reference to the accompanying drawings and in conjunction with preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and substance of the present invention, persons of ordinary skill in the art may make various equivalent modifications or substitutions to the embodiments of the present invention, and such modifications or substitutions are intended to fall within the scope of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A method for preparing carbon / metal hybrid materials from discarded medical protective clothing, characterized in that: The following steps are involved: 1) Soaking discarded medical protective clothing in an alkaline solution, and then adding a saccharide containing a polyhydroxy structure to obtain discarded medical protective clothing with the saccharide adhered to the surface; 2) Soaking the discarded medical protective clothing with sugars adhering to its surface in a soluble metal salt solution, so that the metal ions coordinate and bind with the hydroxyl groups on the sugars containing a polyhydroxy structure, and then drying the discarded medical protective clothing with the metal ions; 3) The dried discarded medical protective clothing is catalytically carbonized under an inert atmosphere to produce a carbon / metal hybrid material.

2. The method for preparing carbon / metal hybrid materials from discarded medical protective clothing according to claim 1, characterized in that: In step 1), the saccharides containing polyhydroxy structures are monosaccharides, disaccharides and polysaccharides.

3. The method for preparing carbon / metal hybrid materials from discarded medical protective clothing according to claim 2, characterized in that: In step 1), the sugar containing a polyhydroxy structure is glucose, sucrose, maltose or fructose.

4. The method for preparing carbon / metal hybrid materials from discarded medical protective clothing according to claim 1, characterized in that: In step 1), the alkaline solution is an aqueous ammonia solution, an aqueous sodium hydroxide solution or an aqueous potassium hydroxide solution; the pH value of the alkaline solution is 8-12.

5. The method for preparing carbon / metal hybrid materials from discarded medical protective clothing according to claim 1, characterized in that: In step 1), the mass ratio of discarded medical protective clothing to the polyhydroxy structure-containing saccharide is 1:0.05-1, and the soaking time is 3-5 hours.

6. The method for preparing carbon / metal hybrid materials from discarded medical protective clothing according to claim 1, characterized in that: In step 2), the soluble metal salt is ferric nitrate, cobalt nitrate, nickel nitrate, ferric chloride, cobalt chloride, nickel chloride, ferric acetate, cobalt acetate, nickel acetate, ferric sulfate, cobalt sulfate or nickel sulfate.

7. The method for preparing carbon / metal hybrid materials from discarded medical protective clothing according to claim 1, characterized in that: In step 2), the mass ratio of the discarded medical protective clothing with sugars adhered to the surface to the soluble metal salt is 1:0.05-0.

2.

8. The method for preparing carbon / metal hybrid materials from discarded medical protective clothing according to claim 1, characterized in that: In step 2), the drying temperature is 60-90°C.

9. The method for preparing carbon / metal hybrid materials from discarded medical protective clothing according to claim 1, characterized in that: In step 3), the inert atmosphere is nitrogen or argon, the catalytic carbonization temperature is 650-850°C, and the heating rate is 5-10°C / min.

10. The carbon / metal hybrid material prepared by the method according to any one of claims 1 to 9.

11. Use of the carbon / metal hybrid material prepared by the method according to any one of claims 1 to 9, characterized in that: Carbon / metal hybrid materials are used as electromagnetic wave absorbing materials.

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