Porous ceramic core loaded with nano composite catalyst and preparation method of porous ceramic core

Abstract

The invention relates to a porous ceramic core loaded with a nano composite catalyst and a preparation method thereof, the porous ceramic core comprises a porous ceramic matrix, a nano composite catalyst layer and a surface functionalization layer in sequence, and the porous ceramic matrix is prepared by mixing, pressing and molding bamboo charcoal powder, zeolite powder, alumina powder, mullite powder and lignocellulose and then firing; the nano-composite catalyst layer is composed of g-C3N4 / TiO2 / Ag3PO4 nano-particles loaded on the surface of the porous ceramic matrix and in pore channels of the porous ceramic matrix; the surface functionalization layer is formed by nano-silver particles modified by the surface of the catalyst layer. Through hierarchical pore structure design and heterojunction energy band regulation and control, the synergistic effect of efficient photocatalytic degradation and pollutant adsorption is achieved, the degradation rate of pollutants such as formaldehyde and benzene is high, good adsorption performance, photocatalytic performance and antibacterial performance are achieved, and the preparation method is reasonable in process and easy for large-scale production and can be applied to the field of air purification.

Description

Technical Field

[0001] The invention relates to the technical field of air purification materials, in particular to a porous ceramic core loaded with a nano composite catalyst and a preparation method thereof. Background Art

[0002] With the acceleration of urbanization and the prevalence of interior decoration materials, harmful gas pollution such as formaldehyde, volatile organic compounds (VOCs), and ammonia has become a major environmental threat to human health. Traditional air purifiers primarily use HEPA filters and activated carbon filters. They draw in air through a built-in fan, filter it, and release clean air. Some models also feature a negative ion generator to enhance purification. However, these systems suffer from limited filtration efficiency, the need for frequent filter replacement, and incomplete removal of harmful gases. Photocatalytic technology, an emerging solution, utilizes photogenerated charge carriers from semiconductor materials (such as TiO2) to decompose pollutants. However, due to material limitations, practical applications still face numerous challenges. For example, conventional TiO2 absorbs only ultraviolet light (which accounts for 4% of the solar spectrum) and has a poor response to visible light, resulting in low energy utilization. High carrier recombination rates reduce catalytic efficiency. Powdered catalysts are prone to agglomeration, and lack efficient carriers for pollutant pre-concentration, resulting in insufficient adsorption-catalytic synergy.

[0003] Early patents (such as CN02112266.0) used a gel-sol method to create nanoporous silica gel as a carrier, then employed a slurry impregnation process to immobilize the nanoparticles. While this improved dispersibility, the silica gel suffered from low mechanical strength, cracking easily upon contact with water, and a monotonous pore size distribution, making it difficult to adapt to varying pollutant molecular sizes. Porous ceramic materials, due to their unique porous structure, possess a large specific surface area and excellent adsorption properties, providing a favorable environment for the adsorption and catalytic decomposition of harmful gases. For example, Jiangsu Wande Environmental Protection Technology Co., Ltd.'s patent (CN119345991A) optimizes ceramic membrane preparation through an eccentric mixing system, but lacks integrated photocatalytic functionality and still relies on physical adsorption. Loading nanoparticles such as Ag and ZnO can enhance light absorption, but this is costly and suffers from poor stability.

[0004] In recent years, researchers have also improved air purification performance through process and structural design refinements. For example, a two-step sintering method (anoxic-oxidative sintering) can be used to control ceramic porosity, but this does not address the issue of catalyst uniformity. Modification with precious metal nanoparticles of silver or gold can extend the photoresponse to the visible light region, but traditional impregnation methods can easily lead to particle agglomeration and reduce the density of active sites. Heterojunction designs can increase specific surface area and catalytic efficiency, but the synthesis process is complex and difficult to integrate with ceramic substrates.

[0005] In summary, existing technologies have failed to effectively integrate multi-stage adsorption carriers, wide-spectrum response catalysts and efficient carrier separation mechanisms, resulting in widespread problems such as single function and low purification efficiency in air purification equipment. Summary of the Invention

[0006] The purpose of the present invention is to solve the problems of low visible light utilization rate, high carrier recombination rate, and insufficient adsorption-catalysis synergy of photocatalysts in existing air purification materials. A porous ceramic core loaded with nanocomposite catalysts and a preparation method thereof are provided. Through multi-level pore structure design and heterojunction energy band regulation, the synergistic effect of efficient photocatalytic degradation and pollutant adsorption is achieved.

[0007] To achieve the above object, the present invention provides a porous ceramic core loaded with a nanocomposite catalyst, comprising: a porous ceramic substrate, a nanocomposite catalyst layer and a surface functionalization layer.

[0008] The porous ceramic matrix is ​​formed by mixing bamboo charcoal powder, zeolite powder, alumina powder, mullite powder and wood cellulose, pressing and molding, and then firing.

[0009] The nanocomposite catalyst layer is composed of g-C3N4 / TiO2 / Ag3PO4 nanoparticles supported on the surface and pores of the porous ceramic substrate; The surface functionalized layer is formed by modifying the surface of the catalyst layer with nano silver particles.

[0010] According to one aspect of the present invention, the porous ceramic matrix is ​​a mixture of bamboo charcoal powder, zeolite powder, alumina powder, mullite powder and wood cellulose: the mass fraction of bamboo charcoal powder is 5%-8%; the mass fraction of zeolite powder is 10%-15%; the mass fraction of alumina powder is 40%-50%; the mass fraction of mullite powder is 8%-12%; and the mass fraction of wood cellulose is 15%-25%.

[0011] According to one aspect of the present invention, the porosity of the porous ceramic substrate is ≥60%, the pore size distribution is 0.5-5 μm, and the specific surface area is ≥300 m² / g.

[0012] According to one aspect of the present invention, the nanocomposite catalyst layer is composed of g-C3N4 / TiO2 / Ag3PO4Z-type heterojunction nanoparticles: the mass ratio of g-C3N4 to TiO2 is 1:1-2; the Ag3PO4 loading is 5%-10% of the total catalyst mass; According to one aspect of the present invention, the total mass of the nanocomposite catalyst layer is 5%-12%, the particle size is 80nm-1μm, and the thickness is 1-30nm.

[0013] According to one aspect of the present invention, the surface functionalized layer is composed of silver nanoparticles: The particle size of the silver nanoparticles is 20-50 nm, and the loading amount is 0.2-0.7%.

[0014] To achieve the above object, the present invention also provides a method for preparing a porous ceramic core loaded with a nanocomposite catalyst, comprising: The method for preparing a porous ceramic matrix comprises the following steps: mixing raw materials in proportion, then ball-milling the raw materials to a fineness of ≤10 μm, and then forming the raw materials and sintering the raw materials through two steps of oxygen-deficient pre-sintering and oxidation sintering to obtain the matrix.

[0015] To prepare the nanocomposite catalyst layer, the substrate was first immersed in a mixture of tetrabutyl titanate and urea to generate a g-C3N4 / TiO2 layer through a hydrothermal reaction, and then immersed in an AgNO3 solution. Na2HPO4 was added and Ag3PO4 was deposited under xenon lamp irradiation to form g-C3N4 / TiO2 / Ag3PO4Z-type heterojunction nanoparticles.

[0016] To prepare the surface functionalized layer, the porous ceramic substrate loaded with the nanocomposite catalyst layer is immersed in a water-ethanol composite solvent of AgNO3, and NaBH4 is added for reduction. After the reaction is completed, the substrate is dried and then calcined at low temperature to form a surface nanosilver functionalized layer.

[0017] According to one aspect of the present invention, a porous ceramic substrate is prepared by mixing raw materials in proportion, then ball-milling to a fineness of ≤10 μm, and then sintering the substrate in two steps of oxygen-deficient pre-sintering and oxidation sintering to obtain the substrate, including: According to the mass fraction of bamboo charcoal powder 5%-8%, the mass fraction of zeolite powder 10%-15, the mass fraction of alumina powder 40%-50%, the mass fraction of mullite powder 8%-12%, the mass fraction of wood cellulose 15%-25%, and the mass fraction of polyvinyl alcohol binder 2%-5%, ball milling is carried out to a slurry fineness of ≤10μm.

[0018] The slurry is injected into the mold for forming. After vacuum degassing, it is pre-fired at 700-800℃ at a rate of 5-10℃ / min in an oxygen-deficient environment.

[0019] Then, air is introduced, the temperature is raised to 1100-1250° C., and the mixture is sintered for 2-4 hours to obtain a multi-level porous ceramic matrix.

[0020] According to one aspect of the present invention, a nanocomposite catalyst layer is prepared, which is composed of g-C3N4 / TiO2 / Ag3PO4Z type heterojunction nanoparticles, comprising: Tetrabutyl titanate and urea are mixed in a mass ratio of 1:2-1:4, the hierarchical porous ceramic substrate is immersed in the mixed solution, and a hydrothermal reaction is carried out at 170-190°C for 11-14 hours to generate a g-C3N4 / TiO2 composite layer.

[0021] Then immerse it in 1.6-4.5% AgNO3 solution, add 0.7-2.8% Na2HPO4 to adjust the pH to 6-7, irradiate with a 500W xenon lamp for 1.5-2.5 hours, photodeposit to form Ag3PO4 nanoparticles, and obtain a porous ceramic core loaded with g-C3N4 / TiO2 / Ag3PO4.

[0022] According to one aspect of the present invention, a surface functionalized layer is prepared, which is composed of silver nanoparticles, comprising: A AgNO3 water-ethanol mixed solvent (ethanol: water = 9:1, containing AgNO3 1.5%-2.0%) was prepared, and the porous ceramic core loaded with g-C3N4 / TiO2 / Ag3PO4 was immersed for 30 minutes.

[0023] Immerse in 0.6%-0.8% NaBH4 solution for reduction for 8-15 minutes, and dry at 50-70℃ for 30-60 minutes.

[0024] Calcination at 260-380°C for 1.5-3 hours forms a uniformly dispersed Ag nanoparticle layer. DETAILED DESCRIPTION Example 1

[0025] Formula: The porous ceramic matrix is ​​composed of 5% bamboo charcoal powder, 10% zeolite powder, 40% alumina powder, 8% mullite powder, 15% wood cellulose, and 2% polyvinyl alcohol binder; the mass ratio of g-C3N4 to TiO2 in the nanocomposite catalyst layer is 1:1, and the Ag3PO4 loading is 5% of the total catalyst mass; the surface functionalization layer is silver nanoparticles with a particle size of 20nm and a loading of 0.2%.

[0026] Preparation method: Preparation of the porous ceramic matrix: All raw materials were mixed according to the formula ratio and ball-milled to a fineness of ≤10μm. The slurry was then injected into a mold and vacuum-degassed. Pre-sintering was performed in an oxygen-deficient environment at a heating rate of 5°C / min to 700°C. Air was then introduced and the temperature was raised to 1100°C at a heating rate of 10°C / min. Sintering was performed for 2 hours to obtain the porous ceramic matrix.

[0027] Loading the nanocomposite catalyst: Tetrabutyl titanate and urea were mixed in a 1:2 mass ratio. The porous ceramic substrate was immersed in the mixture and subjected to a hydrothermal reaction at 170°C for 11 hours to form a g-C3N4 / TiO2 composite layer. Subsequently, the substrate was immersed in a 1.6% AgNO3 solution, and the pH was adjusted to 6 by adding 0.7% Na2HPO4. The solution was then irradiated with a 500W xenon lamp for 1.5 hours. Ag3PO4 nanoparticles were formed on the g-C3N4 / TiO2 composite layer by photodeposition, resulting in a porous ceramic core loaded with g-C3N4 / TiO2 / Ag3PO4.

[0028] Surface functionalization: The porous ceramic cores loaded with g-C3N4 / TiO2 / Ag3PO4 were immersed in a mixed solvent containing 1.5% AgNO3 (a 9:1 ethanol / water volume ratio) for 30 minutes. After removal, the cores were immersed in a 0.6% NaBH4 solution for reduction for 8 minutes, dried at 50°C for 30 minutes, and finally calcined at 260°C for 1.5 hours to form a surface functionalized layer of uniformly dispersed silver nanoparticles.

[0029] Results: Testing showed the porous ceramic core had a porosity of 62%, a pore size distribution of 0.5-5μm, and a specific surface area of ​​320m² / g. Under visible light, it degraded 85% of formaldehyde in the air and 80% of benzene. Example 2

[0030] Formula: The porous ceramic matrix contains 6% bamboo charcoal powder, 12% zeolite powder, 45% alumina powder, 10% mullite powder, 20% wood cellulose, and 3% polyvinyl alcohol binder; the mass ratio of g-C3N4 to TiO2 in the nanocomposite catalyst layer is 1:1.5, and the Ag3PO4 loading is 7% of the total catalyst mass; the silver nanoparticles in the surface functionalization layer have a particle size of 30nm and a loading of 0.4%.

[0031] Preparation method: Preparation of the porous ceramic matrix: Mix the raw materials in the correct proportions and ball-mill to a fineness of ≤10 μm. Molding and vacuum degassing are then performed. Pre-sintering is performed at a heating rate of 8°C / min to 750°C in an oxygen-deficient environment. The temperature is then increased to 1150°C at a heating rate of 10°C / min in an air-admitted atmosphere and sintered for 3 hours.

[0032] Loaded nanocomposite catalyst: Tetrabutyl titanate and urea were mixed in a 1:3 mass ratio. After impregnation, the substrate was subjected to a hydrothermal reaction at 180°C for 12 hours. The substrate was then immersed in a 3% AgNO3 solution, with the pH adjusted to 6.5 by adding 1.5% Na2HPO4. The solution was then irradiated with a 500W xenon lamp for 2 hours for photodeposition to form Ag3PO4 nanoparticles.

[0033] Surface functionalization: The porous ceramic core was immersed in a mixed solvent containing 1.8% AgNO₃ (9:1 ethanol / water by volume) for 35 minutes. The core was then immersed in a 0.7% NaBH₄ solution for 10 minutes, dried at 60°C for 40 minutes, and finally calcined at 300°C for 2 hours to form a surface functionalization layer.

[0034] Effect: Porosity is 65%, pore size distribution is 0.5-5μm, and specific surface area is 350m² / g. Under visible light irradiation, the degradation rate of formaldehyde is 90%, and the degradation rate of benzene is 88%. Example 3

[0035] Formula: The porous ceramic matrix is ​​composed of 7% bamboo charcoal powder, 14% zeolite powder, 48% alumina powder, 11% mullite powder, 22% wood cellulose, and 4% polyvinyl alcohol binder; the mass ratio of g-C3N4 to TiO2 in the nanocomposite catalyst layer is 1:2, and the Ag3PO4 loading is 10% of the total catalyst mass; the silver nanoparticles in the surface functionalization layer have a particle size of 40nm and a loading of 0.7%.

[0036] Preparation method: Preparation of porous ceramic matrix: Mix the raw materials in appropriate proportions and ball-mill to a fineness of ≤10μm. After forming, vacuum degassing is performed. Pre-sinter the ceramic matrix at a rate of 10°C / min to 800°C in an oxygen-deficient environment. After ventilation, heat the matrix to 1250°C and sinter for 4 hours.

[0037] Supported nanocomposite catalyst: Tetrabutyl titanate and urea were mixed in a 1:4 mass ratio. After impregnation, the substrate was subjected to a hydrothermal reaction at 190°C for 14 hours. The substrate was then immersed in a 4.5% AgNO3 solution, with the pH adjusted to 7 by adding 2.8% Na2HPO4. Ag3PO4 nanoparticles were photodeposited using a 500W xenon lamp for 2.5 hours.

[0038] Surface functionalization: The porous ceramic core was immersed in a mixed solvent containing 2% AgNO₃ (9:1 ethanol / water by volume) for 40 minutes. The core was then reduced in a 0.8% NaBH₄ solution for 15 minutes, dried at 70°C for 60 minutes, and finally calcined at 380°C for 3 hours to form a surface functionalization layer.

[0039] Effect: Porosity 68%, pore size distribution 0.5-5μm, specific surface area 380m² / g, formaldehyde degradation rate 92%, benzene degradation rate 91%. Example 4

[0040] Formula: The porous ceramic matrix includes 8% bamboo charcoal powder, 15% zeolite powder, 50% alumina powder, 12% mullite powder, 25% wood cellulose, and 5% polyvinyl alcohol binder; the mass ratio of g-C3N4 to TiO2 in the nanocomposite catalyst layer is 1:1, and the Ag3PO4 loading accounts for 8% of the total catalyst mass; the silver nanoparticles in the surface functionalization layer have a particle size of 25nm and a loading of 0.3%.

[0041] Preparation method: Preparation of the porous ceramic matrix: Mix all raw materials in appropriate proportions, ball-mill to a fineness of ≤10μm, form, and vacuum degas. Pre-sinter the ceramic matrix at a heating rate of 5-10°C / min to 700-800°C in an oxygen-deficient environment. Then, introduce air, heat to 1100-1250°C, and sinter for 2-4 hours.

[0042] Loading nanocomposite catalyst: Tetrabutyl titanate and urea are mixed in a corresponding mass ratio, and the porous ceramic substrate is immersed in it. The mixture is hydrothermally reacted at 170-190°C for 11-14 hours to form a g-C3N4 / TiO2 composite layer; then it is immersed in a 1.6-4.5% AgNO3 solution, 0.7-2.8% Na2HPO4 is added to adjust the pH to 6-7, and a 500W xenon lamp is used for irradiation for 1.5-2.5 hours for photodeposition to form Ag3PO4 nanoparticles.

[0043] Surface functionalization treatment: Prepare a mixed solvent with a volume ratio of ethanol to water of 9:1, add 1.5-2.0% AgNO3, and immerse the porous ceramic core loaded with the catalyst for 30 minutes; then immerse it in 0.6-0.8% NaBH4 solution for reduction for 8-15 minutes, dry it at 50-70°C for 30-60 minutes, and finally calcine it at 260-380°C for 1.5-3 hours to form a surface functional layer.

[0044] Effect: Porosity is 63%, pore size distribution is 0.5-5μm, and specific surface area is 330m² / g. Under visible light irradiation, its degradation rate for formaldehyde is 87% and that for benzene is 86%. Example 5

[0045] Formula: The porous ceramic matrix is ​​composed of 5.5% bamboo charcoal powder, 13% zeolite powder, 43% alumina powder, 9% mullite powder, 18% wood cellulose, and 3.5% polyvinyl alcohol binder; the mass ratio of g-C3N4 to TiO2 in the nanocomposite catalyst layer is 1:1.8, and the Ag3PO4 loading is 6% of the total catalyst mass; the silver nanoparticles in the surface functionalization layer have a particle size of 35nm and a loading of 0.5%.

[0046] Preparation method: Preparation of porous ceramic matrix: raw materials are mixed according to the formula ratio and ball-milled to a fineness of ≤10μm before forming, vacuum degassing, pre-sintering at a high temperature in an oxygen-deficient environment, and then sintering at a high temperature in air to obtain a porous ceramic matrix.

[0047] Loaded nanocomposite catalyst: Tetrabutyl titanate and urea are mixed in a certain mass ratio, the substrate is immersed in it, and a hydrothermal reaction is carried out at 170-190°C to form a g-C3N4 / TiO2 composite layer; then it is immersed in an appropriate amount of AgNO3 solution, Na2HPO4 is added to adjust the pH to an appropriate range, and photodeposition is carried out using a xenon lamp to form Ag3PO4 nanoparticles.

[0048] Surface functionalization treatment: Prepare a suitable concentration of AgNO3 water-ethanol mixed solvent, immerse the substrate loaded with the catalyst in it, and then immerse it in NaBH4 solution for reduction. After drying and calcination, a surface functional layer is formed.

[0049] Effect: Porosity is 66%, pore size distribution is 0.5-5μm, and specific surface area is 365m² / g. Under visible light irradiation, the degradation rate of formaldehyde is 90%, and the degradation rate of benzene is 89%.

[0050] The porous ceramic core loaded with a nanocomposite catalyst and the preparation method thereof of the present invention have the following beneficial effects: Highly efficient photocatalytic performance: By constructing g-C3N4 / TiO2 / Ag3PO4Z-type heterojunction nanoparticles as a nanocomposite catalyst layer, excellent photocatalytic performance is achieved. The heterojunction formed between g-C3N4, TiO2, and Ag3PO4 effectively promotes the separation and migration of photogenerated carriers, significantly reducing the carrier recombination rate and improving photocatalytic activity. Under visible light irradiation, the degradation rate of pollutants such as formaldehyde and benzene in the air is high. For example, the formaldehyde degradation rate in the examples can reach up to 92%, and the benzene degradation rate can reach up to 91%. This effectively solves the problems of low visible light utilization and high carrier recombination rate of existing air purification material photocatalysts.

[0051] Excellent adsorption performance: The porous ceramic matrix is ​​made from bamboo charcoal powder, zeolite powder, alumina powder, mullite powder, and wood cellulose, using a special process. It exhibits a hierarchical pore structure with a porosity of ≥60%, a pore size distribution of 0.5-5μm, and a specific surface area of ​​≥300m² / g. This hierarchical pore structure provides abundant adsorption sites and a large surface area, enabling rapid adsorption of airborne pollutants, enhancing their accumulation capacity and providing ample reactants for subsequent photocatalytic degradation reactions. This achieves a synergistic effect of adsorption and catalysis, addressing the lack of adsorption-catalytic synergy in existing air purification materials.

[0052] Synergistic Effect: The nanocomposite catalyst layer is loaded onto the surface and pores of the porous ceramic substrate, tightly integrating the photocatalyst and the porous ceramic matrix, leveraging their respective strengths. Furthermore, the nanosilver particles in the surface functionalization layer exhibit excellent antibacterial properties, inhibiting the growth of microorganisms that may occur during the photocatalytic process, further enhancing air purification effectiveness. The synergistic effect of these multiple components enables the porous ceramic core to exhibit superior overall performance in the field of air purification.

[0053] Excellent stability and reproducibility: The porous ceramic matrix, prepared through a rational formulation and sintering process, possesses high mechanical strength and chemical stability, maintaining structural integrity during long-term use and providing stable support for the nanocomposite catalyst. Furthermore, the porous ceramic core loaded with the nanocomposite catalyst maintains good photocatalytic activity and adsorption properties after repeated use, making it reusable, reducing operational costs and promising practical application prospects.

[0054] Rational preparation process: The preparation method of the present invention includes the steps of preparing a porous ceramic substrate, loading a nanocomposite catalyst layer, and modifying a surface functional layer. The process is clear and controllable, the operation is simple, and it is easy to scale up. The rational design of the parameters for each step, such as the hydrothermal reaction temperature and time, the photodeposition conditions, and the calcination schedule, effectively ensures the quality and performance consistency of the product, facilitating the large-scale application of the porous ceramic core loaded with nanocomposite catalysts.

[0055] The above description is merely a preferred embodiment of the present application and an illustration of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to the technical solutions formed by the specific combination of the above-mentioned technical features, but also encompasses other technical solutions formed by any combination of the above-mentioned technical features or their equivalents without departing from the inventive concept. For example, a technical solution formed by replacing the above-mentioned features with (but not limited to) technical features with similar functions disclosed in this application.

[0056] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A porous ceramic core loaded with a nanocomposite catalyst, characterized in that: It comprises a porous ceramic matrix, a nanocomposite catalyst layer and a surface functional layer in sequence; The porous ceramic matrix is ​​made by mixing bamboo charcoal powder, zeolite powder, alumina powder, mullite powder and wood cellulose, pressing and molding, and then firing; The nanocomposite catalyst layer is composed of g-C3N4 / TiO2 / Ag3PO4 nanoparticles supported on the surface and pores of the porous ceramic substrate; The surface functionalized layer is formed by modifying the surface of the catalyst layer with nano silver particles.

2. The porous ceramic core loaded with nanocomposite catalyst according to claim 1, characterized in that: In the porous ceramic matrix, the mass fraction of bamboo charcoal powder is 5%-8%, the mass fraction of zeolite powder is 10%-15%, the mass fraction of alumina powder is 40%-50%, the mass fraction of mullite powder is 8%-12%, and the mass fraction of wood cellulose is 15%-25%.

3. The porous ceramic core loaded with nanocomposite catalyst according to claim 1, characterized in that: The porous ceramic matrix has a porosity of ≥60%, a pore size distribution of 0.5-5 μm, and a specific surface area of ​​≥300 m² / g.

4. The porous ceramic core loaded with nanocomposite catalyst according to claim 1, characterized in that: In the nanocomposite catalyst layer, the mass ratio of g-C3N4 to TiO2 is 1:1-2, and the loading amount of Ag3PO4 is 5%-10% of the total catalyst mass.

5. The porous ceramic core loaded with nanocomposite catalyst according to claim 1, characterized in that: The total mass of the nanocomposite catalyst layer is 5%-12% of the total mass of the porous ceramic core. The particle size of the nanocomposite catalyst layer is 80nm-1μm, and the thickness is 1-30nm.

6. The porous ceramic core loaded with nanocomposite catalyst according to claim 1, characterized in that: The particle size of the nano silver particles in the surface functional layer is 20-50 nm, and the loading amount is 0.2%-0.7% of the total mass of the porous ceramic core.

7. A method for preparing a porous ceramic core loaded with a nanocomposite catalyst as claimed in claim 1, characterized in that: The following steps are involved: A porous ceramic matrix is ​​prepared by mixing bamboo charcoal powder, zeolite powder, alumina powder, mullite powder, wood cellulose and polyvinyl alcohol binder in proportion, then ball-milling the mixture to a fineness of ≤10 μm, and then sintering the mixture in two steps of anoxic pre-sintering and oxidative sintering to obtain the matrix. To prepare the nanocomposite catalyst layer, the substrate was first immersed in a mixture of tetrabutyl titanate and urea to generate a g-C3N4 / TiO2 layer through a hydrothermal reaction. The substrate was then immersed in an AgNO3 solution, and Na2HPO4 was added. Ag3PO4 was deposited under xenon lamp irradiation to form g-C3N4 / TiO2 / Ag3PO4 Z-type heterojunction nanoparticles. To prepare the surface functionalized layer, the porous ceramic substrate loaded with the nanocomposite catalyst layer is immersed in a water-ethanol composite solvent of AgNO3, and NaBH4 is added for reduction. After the reaction is completed, the substrate is dried and then calcined at low temperature to form a surface nanosilver functionalized layer.

8. The method for preparing a porous ceramic core loaded with a nanocomposite catalyst according to claim 7, characterized in that: When preparing the porous ceramic matrix, the raw materials are mixed in proportion and then ball-milled to a slurry fineness of ≤10μm. The slurry is injected into a mold for molding. After vacuum degassing, the temperature is raised to 700-800℃ at 5-10℃ / min in an oxygen-deficient environment for pre-sintering. Then, air is introduced, the temperature is raised to 1100-1250℃, and sintered for 2-4 hours to obtain a multi-level porous ceramic matrix.

9. The method for preparing a porous ceramic core loaded with a nanocomposite catalyst according to claim 7, characterized in that: When preparing the nanocomposite catalyst layer, tetrabutyl titanate and urea are mixed in a mass ratio of 1:2-1:4, the multi-level porous ceramic substrate is immersed in the mixed solution, and a hydrothermal reaction is carried out at 170-190°C for 11-14 hours to generate a g-C3N4 / TiO2 composite layer; then, the substrate is immersed in a 1.6-4.5% by mass AgNO3 solution, and a 0.7-2.8% by mass Na2HPO4 solution is added to adjust the pH to 6-7. The substrate is irradiated with a 500W xenon lamp for 1.5-2.5 hours to form Ag3PO4 nanoparticles by photodeposition.

10. The method for preparing a porous ceramic core loaded with a nanocomposite catalyst according to claim 7, characterized in that: When preparing the surface functionalized layer, the prepared AgNO3 water-ethanol mixed solvent has a volume ratio of ethanol to water of 9:1, contains 1.5%-2.0% AgNO3, and the porous ceramic core loaded with g-C3N4 / TiO2 / Ag3PO4 is immersed for 30 minutes; immersed in a NaBH4 solution with a mass fraction of 0.6%-0.8% for reduction for 8-15 minutes, dried at 50-70°C for 30-60 minutes; and calcined at 260-380°C for 1.5-3 hours to form a uniformly dispersed Ag nanoparticle layer.