Carbon-doped boron nitride-loaded metal-based material as well as preparation method and application thereof

Abstract

The invention provides a carbon-doped boron nitride loaded metal-based material as well as a preparation method and application thereof. The preparation method comprises the following steps: mixing a boron source and a nitrogen source, uniformly grinding, adding a carbon source, uniformly grinding again, placing in a high-temperature tubular furnace, introducing inert gas, calcining, sequentially washing with a hydrochloric acid solution, washing with deionized water, drying, and dispersing in an absolute ethyl alcohol solution to obtain a first intermediate product; dissolving a metal precursor salt in deionized water, adding the first intermediate product, sequentially heating and stirring, removing a solvent, drying, and calcining in a muffle furnace to obtain a second intermediate product; and performing reduction treatment on the second intermediate product by using a hydrogen temperature programmed reduction technology to obtain a target product. The carbon-doped boron nitride-loaded metal-based material prepared by the preparation method can efficiently adsorb and purify pollutants such as volatile organic compounds in a cabin, and is beneficial to improving the air quality in the cabin.

Description

Technical Field

[0001] The present invention relates to the technical field of pollutant purification, and particularly relates to a carbon-doped boron nitride-supported metal-based material, a preparation method thereof, and an application thereof. Background Art

[0002] As a closed space where crew members work and live for a long time, the air environmental quality of ship cabins directly affects personnel health and operation efficiency. However, restricted by the special environment of the cabins, air pollution in ship cabins presents the following significant characteristics: furniture, composite materials, and electronic equipment densely arranged in the cabins continuously release volatile organic compounds such as formaldehyde, benzene series, and TVOC (the measured formaldehyde concentration in the cabins can reach 5-8 times the national standard limit). At the same time, CO2, body pollution generated by personnel activities, and microbial aerosols (such as mold spores and bacterial endotoxins) bred in a humid environment form multiple pollution superpositions. Compared with the indoor environment of buildings, the airtightness of ship cabins is extremely high (the natural ventilation rate is usually less than 0.3 times / h), and the mechanical ventilation system is limited by marine climate and navigation conditions and is difficult to operate continuously, resulting in a fast pollutant diffusion rate and a high cumulative concentration, forming a long-term exposure risk.

[0003] Currently, the commonly used air purification technologies mainly include adsorption, photocatalysis, membrane separation and other technologies. The adsorption purification technology relies on the physical adsorption of porous materials such as activated carbon, but the adsorption capacity is limited (the typical value is ≤400 mg / g), and it is easy to be saturated and ineffective in a high-concentration pollution environment (the cycle is about 2-4 weeks), and the adsorption module needs to be replaced frequently, resulting in secondary pollution and high operation and maintenance costs; the photocatalysis technology is that conventional catalysts such as TiO2 can decompose VOCs under the excitation of ultraviolet light, but its quantum efficiency is less than 5%, and the light intensity in ship cabins is insufficient (usually <150 lux) and the vibration and impact are large, resulting in a significant reduction in catalytic activity. Although the nano-modified catalyst has been improved, it is easy to be deactivated and the stability is insufficient under typical ship conditions such as high humidity (RH>80%) and salt spray corrosion; the membrane separation technology is effective for particulate filtration, but it cannot remove gaseous pollutants, and the membrane module is easily blocked by oil stains and the maintenance is complicated.

[0004] Long-term exposure to high-concentration VOCs and microbial aerosols will induce respiratory inflammation, immunosuppression and even cancer risks in crew members. The International Maritime Organization (IMO) Resolution MSC.435(98) clearly requires that the formaldehyde concentration in ship cabins be controlled below <0.08 ppm, but the existing technology is difficult to meet the standard stably in a closed cabin. Especially during long voyages, the contradiction between continuous pollutant accumulation and attenuation of purification efficiency is particularly prominent, and there is an urgent need to develop high-efficiency purification materials suitable for extreme ship conditions. Summary of the Invention

[0005] In view of the above-mentioned disadvantages of the prior art, the purpose of the present invention is to provide a carbon-doped boron nitride-supported metal-based material, its preparation method and application, which are used to solve the problem that due to the strong sealing and poor ventilation of ship cabins and high pollutant concentrations, the conversion efficiency of existing materials is difficult to meet the long-term purification requirements of ships.

[0006] To achieve the above object and other related objects, in the first aspect, the present invention provides a preparation method of a carbon-doped boron nitride-supported metal-based material, including the following steps:

[0007] Mix and grind the boron source and nitrogen source evenly, add the carbon source and grind evenly again, then place it in a high-temperature tube furnace, introduce an inert gas for calcination. After the calcination is completed, wash it successively with hydrochloric acid solution, deionized water, dry it, and disperse it in an anhydrous ethanol solution to obtain a first intermediate product;

[0008] Dissolve the metal precursor salt in deionized water, add the first intermediate product, and after heating and stirring, removing the solvent, and drying successively, place it in a muffle furnace for calcination to obtain a second intermediate product;

[0009] Use the hydrogen temperature-programmed reduction technique to reduce the second intermediate product to obtain the target product.

[0010] Specifically, the preparation method includes the following steps:

[0011] Mix and grind the boron source and nitrogen source evenly, add the carbon source and grind evenly again, then place it in a high-temperature tube furnace, introduce an inert gas at a flow rate of 100 mL / min to 150 mL / min for calcination. After the calcination is completed, wash it successively with a 5% - 20% hydrochloric acid solution, remove the hydrochloric acid solution, wash it again with deionized water, dry it in an oven at 60°C - 100°C, and after drying, disperse it in an anhydrous ethanol solution and stir evenly to obtain a first intermediate product;

[0012] Dissolve the metal precursor salt in deionized water, stir to dissolve, then add the first intermediate product, heat and stir at 40°C - 60°C for 6 h - 8 h successively, remove the solvent, dry it in an oven at 60°C - 80°C for 10 h - 12 h, and place the dried product in a muffle furnace for calcination to obtain a powdery second intermediate product;

[0013] Use hydrogen temperature-programmed reduction to reduce the powdery second intermediate product to obtain a carbon-doped boron nitride-supported metal-based material.

[0014] Optionally, the boron source is selected from one or more of boric acid, melamine borate, and boron oxide.

[0015] Optionally, the nitrogen source is selected from one or more of urea, melamine, and dopamine.

[0016] Optionally, the carbon source is selected from glucose and / or citric acid.

[0017] Optionally, the metal precursor salt is selected from one or more of silver nitrate, platinum chloride, and palladium chloride.

[0018] Optionally, the mass ratio of the boron source to the nitrogen source is 0.9:1;

[0019] The carbon source accounts for 10 wt% to 40 wt% of the total mass of the boron source, nitrogen source, and carbon source;

[0020] The metal element in the metal precursor salt accounts for 0.5 wt% to 2 wt% of the target product.

[0021] Optionally, the temperature in the high-temperature tube furnace is 1200 °C to 1600 °C; when calcining in a muffle furnace, the temperature is raised at a rate of 1 °C / min to 2 °C / min, and when the temperature reaches 500 °C to 600 °C, it is calcined for 4 h to 6 h.

[0022] Optionally, the second intermediate product is reduced by using the hydrogen temperature-programmed reduction technique, and the specific steps include:

[0023] Introduce nitrogen at 30 mL / min to 50 mL / min and pretreat for 30 min to 60 min at a temperature not lower than 200 °C to 300 °C;

[0024] Cool to room temperature, introduce a mixture of hydrogen and nitrogen at 30 mL / min to 50 mL / min, and carry out a reduction reaction at a temperature of 300 °C to 500 °C for 0.5 h to 2 h; the volume of hydrogen accounts for 10 vol% of the mixture gas.

[0025] In a second aspect, the present application provides a metal-based material supported by carbon-doped boron nitride, and the material is prepared by the preparation method of the metal-based material supported by carbon-doped boron nitride as described above.

[0026] In a third aspect, the present application provides a carbon-doped boron nitride-supported metal-based material prepared by the preparation method of the carbon-doped boron nitride-supported metal-based material as described above, or the application of the carbon-doped boron nitride-supported metal-based material as described above in removing pollutants in a ship cabin.

[0027] As described above, a carbon-doped boron nitride-supported metal-based material, its preparation method, and application of the present application have the following beneficial effects:

[0028] The preparation method of the carbon-doped boron nitride supported metal-based material provided by this application is simple, easy to operate, low in cost, green and environmentally friendly. A carbon-doped layered boron nitride support is prepared by a pyrolysis method, which has a strong photogenerated carrier lifetime and electron transport ability, and is rich in edge active sites, which is beneficial to stably carry a metal with a light conversion ability.

[0029] The carbon-doped boron nitride supported metal-based material provided by this application includes a carbon-doped layered boron nitride support and a metal with a light conversion ability. The support has a strong adsorption ability and can adsorb and enrich pollutants, and then use the photoactivity of the metal to convert the enriched pollutants, so as to realize the synergistic conversion of pollutants in the cabin. The carbon-doped boron nitride supported metal-based material of this application can efficiently adsorb and purify pollutants such as volatile organic compounds in the cabin, which is beneficial to improving the air quality in the cabin. Description of the Drawings

[0030] Figure 1 It is a scanning electron microscope (SEM) image of the carbon-doped boron nitride supported metal-based material prepared in Example 2 of this application. Detailed Embodiments

[0031] The following further elaborates this application in combination with specific embodiments. It should be understood that these embodiments are only used to illustrate this application and not to limit the protection scope of this application.

[0032] The following specific examples illustrate the implementation manners of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. This application can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application.

[0033] Unless otherwise specified, the raw materials, solvents and reagents in the embodiments of this application are all purchased through commercial channels.

[0034] Example 1

[0035] This example provides a preparation method of a carbon-doped boron nitride supported platinum-based material, which includes the following steps:

[0036] (1) Mix boron oxide and urea with a mass ratio of 0.9:1 and grind them evenly. Then add 10 wt% citric acid (i.e., citric acid accounts for 10% of the total mass of boron oxide, urea, and citric acid), and grind evenly again. Place it in a high-temperature tube furnace, heat up to 1500 °C, and introduce 100 mL / min of inert gas for calcination. After the calcination is completed, the product is washed successively with 20% hydrochloric acid solution, the hydrochloric acid solution is removed, and then washed again with deionized water. The washed sample is placed in an oven at 80 °C for drying, and after drying, it is dispersed in anhydrous ethanol solution and stirred evenly to obtain the first intermediate product;

[0037] (2) Dissolve platinum chloride in deionized water (where the platinum element accounts for 1.5 wt% of the mass of the expected carbon-doped boron nitride supported platinum-based material), stir to dissolve, then add the first intermediate product, heat and stir at 60 °C for 8 h. After removing the solvent, place it in an oven at 80 °C for drying for 12 h. Place the dried product in a muffle furnace and heat it up at a heating rate of 2 °C / min. Heat up to 550 °C and calcine for 4 h to obtain a powdery second intermediate product;

[0038] (3) Use hydrogen temperature-programmed reduction to reduce the powdery second intermediate product. The specific steps include: First, introduce 30 mL / min of nitrogen (N2) and pretreat at 300 °C for 30 min. Secondly, cool to room temperature, introduce a mixture of 50 mL / min of hydrogen (H2) and nitrogen (N2) (where hydrogen accounts for 10% of the total volume of the hydrogen and nitrogen mixture), and reduce at 350 °C for 0.5 h. Finally, obtain the carbon-doped boron nitride supported platinum-based material.

[0039] Performance test and analysis:

[0040] Under room temperature conditions, use a purification device with a xenon lamp light source, load 1 g of the carbon-doped boron nitride supported platinum-based material prepared in this example, and conduct tests on the simulated chamber environment under the irradiation of 1 sunlight intensity and a ventilation rate of 5000 L / h. Among them, the concentrations of toluene and formaldehyde are reduced by 94% and 92% respectively within 2 hours.

[0041] Example 2

[0042] This example provides a preparation method of a carbon-doped boron nitride supported palladium-based material, including the following steps:

[0043] (1) Mix boric acid and urea with a mass ratio of 0.9:1 and grind them evenly. Then add 10 wt% glucose (i.e., glucose accounts for 10% of the total mass of boric acid, urea, and glucose), and grind evenly again. Place it in a high-temperature tube furnace, heat up to 1300 °C, and introduce 100 mL / min of inert gas for calcination. After the calcination is completed, the product is washed successively with 10% hydrochloric acid solution, the hydrochloric acid solution is removed, and then washed again with deionized water. The washed sample is placed in an 80 °C oven for drying. After drying, it is dispersed in an anhydrous ethanol solution and stirred evenly to obtain the first intermediate product;

[0044] (2) Dissolve palladium chloride in deionized water (where the palladium element accounts for 1 wt% of the mass of the expected palladium-based material supported by carbon-doped boron nitride), stir to dissolve, then add the first intermediate product, heat and stir at 60 °C for 8 h. After removing the solvent, place it in an 80 °C oven for drying for 12 h. Place the dried product in a muffle furnace and heat it at a heating rate of 2 °C / min. Heat up to 550 °C and calcine for 4 h to obtain a powdery second intermediate product;

[0045] (3) Use temperature-programmed reduction with hydrogen to reduce the powdery second intermediate product. The specific steps include: First, introduce 30 mL / min of nitrogen (N2) and pretreat at 200 °C for 60 min. Second, cool to room temperature, introduce a mixture of 30 mL / min of hydrogen (H2) and nitrogen (N2) (where hydrogen accounts for 10% of the total volume of the hydrogen and nitrogen mixture), and reduce at 350 °C for 1 h. Finally, obtain the palladium-based material supported by carbon-doped boron nitride.

[0046] Scan the prepared palladium-based material supported by carbon-doped boron nitride under a scanning electron microscope (SEM). The scanning image is as Figure 1 shown.

[0047] Performance test and analysis:

[0048] Under room temperature conditions, use a purification device with a xenon lamp light source. Load 1 g of the palladium-based material supported by carbon-doped boron nitride prepared in this example. Under the irradiation of 1 sunlight intensity and a ventilation volume of 5000 L / h, conduct tests on the simulated chamber environment. Among them, the concentrations of toluene and formaldehyde are reduced by 89% and 90% respectively within 2 hours.

[0049] Example 3

[0050] This example provides a preparation method of a silver-based material supported by carbon-doped boron nitride, including the following steps:

[0051] (1) Mix melamine borate and urea with a mass ratio of 0.9:1 and grind them evenly. Subsequently, add 15 wt% glucose (i.e., glucose accounts for 15% of the total mass of melamine borate, urea, and glucose), and grind evenly again. Place it in a high-temperature tube furnace, heat up to 1600 °C, and introduce 150 mL / min of inert gas for calcination. After the calcination is completed, the product is washed successively with 15% hydrochloric acid solution, the hydrochloric acid solution is removed, and then washed again with deionized water. The washed sample is placed in an oven at 80 °C for drying. After drying, it is dispersed in an anhydrous ethanol solution and stirred evenly to obtain the first intermediate product;

[0052] (2) Dissolve silver nitrate in deionized water (where the silver element accounts for 1.5 wt% of the mass of the expected silver-based material supported by carbon-doped boron nitride), stir to dissolve, then add the first intermediate product, heat and stir at 80 °C for 8 h. After removing the solvent, place it in an oven at 80 °C for drying for 12 h. Place the dried product in a muffle furnace and heat it at a heating rate of 2 °C / min. Heat up to 400 °C and calcine for 6 h to obtain a powdery second intermediate product;

[0053] (3) Use temperature-programmed reduction with hydrogen to reduce the powdery second intermediate product. The specific steps include: First, introduce 50 mL / min of nitrogen (N2) and pretreat at 200 °C for 60 min. Secondly, cool to room temperature, introduce a mixture of 50 mL / min of hydrogen (H2) and nitrogen (N2) (where hydrogen accounts for 10% of the total volume of the hydrogen and nitrogen mixture), and reduce at 300 °C for 1 h. Finally, obtain the silver-based material supported by carbon-doped boron nitride.

[0054] Performance test and analysis:

[0055] Under room temperature conditions, use a purification device with a xenon light source, load 1 g of the silver-based material supported by carbon-doped boron nitride prepared in this example, and conduct tests on the simulated chamber environment under the irradiation of 1 sunlight intensity and a ventilation rate of 5000 L / h. The concentrations of toluene and formaldehyde are reduced by 88% and 91% respectively within 2 hours.

[0056] The metal-based materials supported by carbon-doped boron nitride prepared in Examples 1 to 3 of this application all have excellent pollutant purification capabilities.

[0057] The above embodiments are only illustrative of the principles and effects of the present invention, and are not used to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes completed by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A preparation method of a carbon-doped boron nitride-supported metal-based material, characterized in that, It includes the following steps: Mix the boron source and nitrogen source and grind them evenly. After adding the carbon source and grinding evenly again, place them in a high-temperature tube furnace, introduce an inert gas for calcination. After the calcination is completed, wash with hydrochloric acid solution, deionized water in sequence, dry, and then disperse in an anhydrous ethanol solution to obtain a first intermediate product; Dissolve the metal precursor salt in deionized water, add the first intermediate product, and after heating and stirring, removing the solvent, and drying in sequence, place it in a muffle furnace for calcination to obtain a second intermediate product; Use the hydrogen temperature-programmed reduction technique to reduce the second intermediate product to obtain the target product.

2. The preparation method according to claim 1, characterized in that, The boron source is selected from one or more of boric acid, melamine borate, and boron oxide.

3. The preparation method according to claim 1, wherein, The nitrogen source is selected from one or more of urea, melamine, and dopamine.

4. The preparation method according to claim 1, wherein The carbon source is selected from glucose and / or citric acid.

5. The preparation method according to claim 1, wherein The metal precursor salt is selected from one or more of silver nitrate, platinum chloride, and palladium chloride.

6. The preparation method according to claim 1, wherein The mass ratio of the boron source to the nitrogen source is 0.9:1; The carbon source accounts for 10wt% - 40wt% of the total mass of the boron source, nitrogen source, and carbon source; The metal element in the metal precursor salt accounts for 0.5wt% - 2wt% of the target product.

7. The preparation method according to claim 1, wherein The temperature in the high-temperature tube furnace is 1200°C - 1600°C; when calcining in the muffle furnace, heat up at a heating rate of 1°C / min - 2°C / min, heat up to 500°C - 600°C, and calcine for 4h - 6h.

8. The preparation method according to claim 1, characterized in that, Use the hydrogen temperature-programmed reduction technique to reduce the second intermediate product. The specific steps include: Introduce nitrogen at 30mL / min - 50mL / min and pretreat at no less than 200°C - 300°C for 30min - 60min; Cool to room temperature, introduce a mixture of hydrogen and nitrogen at 30mL / min - 50mL / min, and carry out a reduction reaction at a temperature of 300°C - 500°C for 0.5h - 2h; the volume of hydrogen accounts for 10vol% of the mixture gas.

9. A carbon-doped boron nitride-supported metal-based material, characterized in that, Prepared by the preparation method of the metal-based material supported by carbon-doped boron nitride according to any one of claims 1 - 8.

10. The application of the carbon-doped boron nitride-supported metal-based material prepared by the preparation method of the carbon-doped boron nitride-supported metal-based material according to any one of claims 1 - 8, or the carbon-doped boron nitride-supported metal-based material according to claim 9 in removing pollutants in a ship cabin.

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