CN114853463A

CN114853463A - Nitrogen-doped phosphate-based photocatalytic ceramic product and preparation method thereof

Info

Publication number: CN114853463A
Application number: CN202210403410.5A
Authority: CN
Inventors: 刘一军; 黄玲艳; 曹丽云; 黄剑锋; 李嘉胤; 张金津; 潘利敏; 汪庆刚
Original assignee: Monalisa Group Co Ltd
Current assignee: Monalisa Group Co Ltd
Priority date: 2022-04-18
Filing date: 2022-04-18
Publication date: 2022-08-05
Anticipated expiration: 2042-04-18
Also published as: CN114853463B

Abstract

The invention discloses a nitrogen-doped phosphate-based photocatalytic ceramic product and a preparation method thereof. The preparation method comprises the following steps: applying a glaze composition having a phosphate-based component that promotes preferential growth of the crystallographic structure orientation to the surface of the ceramic body; firing the ceramic body after applying the glaze composition; and calcining the sintered ceramic body and the nitrogen-containing powder in an inert atmosphere to obtain the nitrogen-doped phosphate-based photocatalytic ceramic product.

Description

Nitrogen-doped phosphate-based photocatalytic ceramic product and preparation method thereof

Technical Field

The invention belongs to the field of ceramic glaze materials, and particularly relates to a nitrogen-doped phosphate-based photocatalytic ceramic product and a preparation method thereof.

Background

The traditional architectural ceramic industry has excess capacity and gradually narrow market trend, and the surface functionalization of ceramic products is an important development direction for improving the value of the traditional ceramic materials and innovating and developing the market of enterprises. In China, ceramic products with heat insulation, heat preservation, luminescence, antibacterial ceramic and other functions have been developed by partial ceramic enterprises. At present, the building sanitary ceramic products are largely used in engineering construction, capital construction and home decoration in China. In the face of the threat of toxic organic matters or gases released by various chemical products to the household environment or human health, consumers put great demands on environment-friendly architectural ceramics. The development of ceramic products with the functions of environmental protection and toxic organic pollutant degradation is one of the problems to be solved in the building ceramic industry in China. Whether or not the photocatalyst can be reasonably applied to the ceramic product having the above functions is an important subject to solve the above problems.

The traditional building sanitary and daily ceramic glaze materials are mainly divided into frit glaze and raw glaze. The fritted glaze has few surface defects and is widely used by more and more ceramic enterprises. The production and research of fritted glazes mainly focuses on the following aspects: the use and research of lead-free, cadmium-free and other non-toxic elements, namely lead-free frit glaze; high-temperature wear-resistant frit glaze; transparent glaze with excellent mirror surface decoration effect, namely full-polished glaze; also, a bleeding glaze, an opacifying glaze, a crystallized glaze, etc. How to obtain a ceramic product with a glaze crystallization effect and a photocatalytic function is an important technical problem to be solved by the invention.

Disclosure of Invention

Aiming at the problems, the invention provides a nitrogen-doped phosphate-based photocatalytic ceramic product and a preparation method thereof. The product uses the glaze composition with phosphate-based components for promoting the oriented preferential growth of the crystal structure, and the glaze composition can preferentially form a high-activity crystal structure and directionally grow in a glaze layer under the promotion of phosphate system ground coat, so that the preferential distribution of the crystal components on the surface of the glaze layer is promoted, and the full exposure of the active sites on the surface of the ceramic glaze is ensured. Meanwhile, manganese tungstate with excellent photocatalytic degradation performance is introduced into the glaze composition, so that the glaze composition has good degradation performance on toxic gases such as formaldehyde, phenyl compounds and the like.

In a first aspect, the present invention provides a method for preparing a nitrogen-doped phosphate-based photocatalytic ceramic product. The preparation method comprises the following steps:

applying a glaze composition having a phosphate-based component that promotes preferential growth of the crystallographic structure orientation to the surface of the ceramic body; the glaze composition comprises the following raw materials: by mass percentage, 80-90% of powder A, 5-10% of manganese tungstate and 5-10% of kaolin; the powder A comprises the following raw materials: by mass percent, SiO ₂ 15～30％、AlPO ₄ 6～12％、Mn ₃ (PO ₄ ) ₂ 6～10％、Li ₃ PO ₄ 20～54％、Na ₃ PO ₄ 16～21％、K ₃ PO ₄ 20～29％；

Firing the ceramic body after applying the glaze composition;

and calcining the fired ceramic body and the nitrogen-containing powder in an inert atmosphere to obtain the nitrogen-doped phosphate-based photocatalytic ceramic product. In some embodiments, the nitrogen-containing powder is urea.

In the glaze composition composed of conventional oxides such as silicon oxide, aluminum oxide, calcium oxide, sodium oxide, etc., the crystalline component is not easily exposed sufficiently on the surface of the glaze layer, and the active ingredient of the glaze does not easily exhibit good photocatalytic activity. The ground glaze component of the phosphate system has a different melt liquid viscosity and metal ion diffusion rate at high temperature compared to the glaze composition of the oxide system, under which conditions the rate of oriented growth of the crystalline glaze component and the normal distribution within the bulk crystalline glaze layer exhibit significant variation. Specifically, under a phosphate-based ground glaze system, the oriented growth of the manganese tungstate-based crystalline glaze is preferentially distributed on the surface of a glaze layer, and one-dimensional orientation is formed, so that conditions can be provided for the sufficient exposure and growth of a high-activity crystalline glaze system. In addition, the sintered ceramic body and the nitrogen-containing powder are calcined in an inert atmosphere, so that nitrogen elements can be embedded into the surface of a glazed glass phase in the form of solid solution, surface cation migration is stabilized by means of nitrogen doping in repeated catalytic circulation, an active structure is maintained, and the degradation efficiency is improved.

Preferably, the powder A is a powder in the form of a frit.

Preferably, the preparation process of the frit comprises the following steps: uniformly mixing the raw materials of the powder A, then sieving the mixture at a first temperature for 10 to 20 minutes, continuously keeping the temperature at a second temperature for 10 to 20 minutes, keeping the temperature at a third temperature for 10 to 20 minutes, and then quenching and crushing the mixture to obtain a frit; wherein the first temperature is 600-900 ℃, the second temperature is 700-1000 ℃, and the third temperature is 1300-1500 ℃; preferably, the second temperature is 50 to 200 ℃ higher than the first temperature.

Preferably, the mesh number of the sieve is 30 to 100 meshes.

Preferably, the particle size of the powder A is 100-300 meshes.

Preferably, the glaze composition generates linear crystals growing in a scattering orientation under a high-temperature firing environment.

Preferably, the linear crystal is a manganese tungstate crystal.

Preferably, the maximum firing temperature is 1100-1300 ℃, and the firing period is 60-170 minutes.

Preferably, the inert atmosphere for calcination is argon.

Preferably, the calcination temperature is 400-800 ℃ and the calcination time is 30-90 minutes.

Preferably, the glaze composition is applied to the surface of the ceramic body in the form of a glaze slip; the glaze slip comprises a dispersant and water in addition to the glaze composition; preferably, the water accounts for 40-60% of the mass of the glaze slip, and the dispersant accounts for 0.1-0.5% of the mass of the glaze slip.

Preferably, the glaze slip forms a 0.05-0.3 mm crystal glaze layer on the surface of the ceramic body.

In a second aspect, the present invention provides a nitrogen-doped phosphate-based photocatalytic ceramic product obtained by the preparation method described in any one of the above.

Drawings

FIG. 1 is an XRD pattern of the glaze layer of example 1;

FIG. 2 is a graph showing the photocatalytic degradation of formaldehyde in examples 1 to 3 and comparative example 1;

FIG. 3 is a graph showing the performance of photocatalytic degradation of phenyl compounds according to examples 1 to 3 and comparative example 1;

fig. 4 is a digital photograph of a nitrogen-doped phosphate-based photocatalytic ceramic product.

Detailed Description

The present invention is further illustrated by the following examples, which are to be understood as merely illustrative of, and not restrictive on, the present invention. Unless otherwise specified, each percentage means a mass percentage. The following is an exemplary illustration of the method of making the nitrogen-doped phosphate-based photocatalytic ceramic product of the present invention.

A glaze composition in which a phosphate-based component promotes the preferential growth of the crystal structure orientation is applied to the surface of the ceramic body. The composition and specification of the ceramic body are not particularly limited, and a construction ceramic body commonly used in the art may be used.

The glaze composition comprises the following raw materials: by mass percentage, 80-90% of powder A, 5-10% of manganese tungstate and 5-10% of kaolin.

The powder A is the main component of the glaze composition, plays the role of ground coat in the glaze composition and provides a liquid phase environment in a high-temperature molten state. The powder A comprises the following raw materials: by mass percent, SiO ₂ 15～30％、AlPO ₄ 6～12％、Mn ₃ (PO ₄ ) ₂ 6～10％、Li ₃ PO ₄ 20～54％、Na ₃ PO ₄ 16～21％、K ₃ PO ₄ 20-29%. The powder A provides a liquid environment for nucleation and growth of active manganese tungstate crystals in a high-temperature environment, so that the active manganese tungstate crystals can grow at a higher rate. If the powder A is replaced by the traditional feldspar and clay, the powder A can be replaced by the traditional feldspar and clayThe crystal grain size of the crystal is small, even the crystal grain growth cannot be promoted, and the formed oriented growth structure is few. This is because the nucleation rate of manganese tungstate nuclei is low and it is difficult to directly nucleate growth in a short time by using conventional feldspar or clay as the ground glaze component of the glaze composition. The crystal glaze formed by feldspar or clay has long growth time, the heat preservation time is usually 4-10 hours only under the high-temperature condition, and the total firing period is more than 15 hours. The crystal flower morphology of the glaze composition is easy to control, the energy consumption is saved, the heat preservation time under the high-temperature condition is only 5-20 minutes, and the total firing period is 60-170 minutes.

As described above, powder A provides an environment for nucleation and growth of crystals, and allows manganese tungstate to rapidly nucleate. If the mass percentage of the powder A in the glaze composition is lower than 80%, the crystal component can not effectively migrate and grow in a high-temperature melting state, the crystal glaze nucleation is not easy, the crystal nucleus growth size distribution is not uniform, and the glaze decoration effect is poor. If the mass ratio of powder A in the glaze composition is higher than 90%, the number of the crystallized grains is easily melted to be remarkably reduced, and the decorative effect is also deteriorated.

Preferably, said powder a is a powder in the form of a frit. The crystallization effect and the catalytic effect cannot be simultaneously excellent by directly using the powder A in the form of a raw material. The reason is that the fusion cake powder is more uniformly mixed than the raw material, and the distribution of nucleation crystal flowers is more uniform. Meanwhile, the frit powder can also reduce the sintering temperature and expand the sintering range. The melting temperature of the frit is high, so that various raw materials are fully reacted and melted at high temperature to be converted into a glassy substance, and the glassy substance is remelted for the second time during firing, so that the melting point of the glaze is reduced, the melting range of the glaze is expanded, and convenience is brought to production control. Moreover, compared with the raw material, the frit powder improves the glaze quality and reduces the glaze shrinkage. When the frit is prepared, the decomposable substances and certain volatile matters in the raw materials are discharged in advance, and the processes are not generated during glaze firing, so that the pinhole defects are reduced. Meanwhile, the glaze material after melting has small loss of burning during glaze firing, almost does not shrink, can better adapt to a blank body, and reduces the defects of glaze rolling, glaze shrinkage and the like. Therefore, the glaze composition prepared by the invention has uniform color generation, improves the coloring efficiency, increases the stability, suspension property and adhesion with a blank body of the glaze and reduces bubbles. Although the raw material can realize crystallization and has a certain catalytic effect, the crystal nucleus growth of the obtained crystallized glaze is difficult to control, the repeatability is extremely poor, the crystal flower size is limited, and the catalytic effect is obviously limited.

Weighing the raw materials according to the raw material composition of the powder A, mixing, grinding and sieving to obtain a mixture. The mixing means may be dry mixing. The number of the sieved meshes is 30-100 meshes. Putting the mixture into a crucible, putting the crucible into an electric furnace, keeping the temperature for 10-20 minutes at a first temperature, keeping the temperature for 10-20 minutes at a second temperature, keeping the temperature for 10-20 minutes at a third temperature, quenching and crushing to obtain a fusion cake; wherein the first temperature is 600-900 ℃, the second temperature is 700-1000 ℃, and the third temperature is 1300-1500 ℃; preferably, the second temperature is 50 to 200 ℃ higher than the first temperature. And taking the frit out of the water, drying, then placing the frit into a ball milling tank for grinding, and drying for later use. During the ball milling process, for example, the frit: the mass ratio of the grinding balls is 1: 6. can be sieved after being ground for 1 to 6 hours.

The particle size of the powder A is 100-300 meshes. The frit is further ground in order to refine it such that the components of the frit are sufficiently uniformly distributed under high temperature conditions. The higher the degree of refinement, the more uniform the growth of the crystal flowers.

Manganese tungstate acts as an active material in the glaze composition and acts as a photocatalyst. The mass percentage of the manganese tungstate in the glaze composition is controlled to be 5-10%. The photocatalytic effect is obviously weakened when the content of manganese tungstate is too high or too low. The manganese tungstate has low content and few crystal flowers, and photocatalytic degradation components are reduced, so that the catalytic effect is weakened; the high content of manganese tungstate causes more crystal flowers in nucleation, but the crystal flowers are mutually overlapped during nucleation, so that the distribution is uneven, and the decorative effect and the photocatalytic effect are also influenced.

Although the powder A also contains manganese, the manganese in the powder A is an element composition used as the ground coat, and the manganese tungstate introduced into the crystal glaze can be used as a crystallization agent and has a photocatalytic degradation effect.

The kaolin contains Al ₂ O ₃ ·2SiO ₂ ·2H ₂ And O. The kaolin can increase the melting temperature of the glaze and improve the suspension property so that the glaze is not easy to settle. If the content of the kaolin is too small, the dispersion uniformity and stability of the glaze cannot be effectively ensured; if the kaolin content is too high, the active ingredients of the glaze are easily wrapped by the kaolin and cannot be exposed, so that the catalytic degradation performance of the glaze composition is limited.

The glaze composition is prepared. Uniformly mixing the powder A, the manganese tungstate and the kaolin, and levigating the mixture in a ball milling tank. In the ball milling process, controlling the materials: grinding balls: the mass ratio of water is 1: 1: 1, grinding for 1-6 hours, sieving by a 300-mesh sieve, and drying for later use.

And firing the ceramic body after the glaze composition is applied. And (3) sintering by oxidizing flame in a roller kiln, preferably quick sintering. The maximum firing temperature is 1100-1300 ℃, and the firing period is 60-170 minutes. The heat preservation time of the highest firing temperature can be 5-20 minutes.

The glaze composition may be prepared in the form of a glaze slip to be applied to the surface of the ceramic body. The glaze slip includes water and a dispersant in addition to the glaze composition. The mass percentage of water in the glaze slip is 40-60%, and the mass percentage of the dispersing agent is 0.1-0.5%. The dispersant includes, but is not limited to, polyacrylic acid ammonium salt, and the like. The components in the glaze slip are uniformly dispersed by stirring. The glaze slip forms a 0.05-0.3 mm crystal glaze layer on the surface of the ceramic body. In this case, the ceramic body may be dried before firing. For example, drying at 50-100 deg.C.

And (3) preserving the heat of the sintered ceramic body and the nitrogen-containing components for 30-90 min at 400-800 ℃ in an inert atmosphere to obtain the nitrogen-doped phosphate-based photocatalytic ceramic product. The purpose of controlling the temperature and time of nitrogen doping within the above ranges is to control the decomposition rate of the nitrogen-containing molecules and to control the nitrogen doping. In some technical schemes, the nitrogen content of the nitrogen source can be 20-70% by mass. For example, urea powder is spread on the surface of the ceramic body after firing. The amount of urea is per 100cm ² 0.5-2.0 g of urea powder is used on the surface of the ceramic body. The urea powder can also be replaced by melamine.

The glazed ceramic body can not be sintered after urea powder is paved on the surface of the glazed ceramic body. The nitrogen doping of the present invention needs to be performed under an inert atmosphere. If the urea powder is paved on the surface of the ceramic body and then sintered, the growth of the crystal orientation structure and the formation of the glass phase structure in the glaze layer can be influenced, and the special solid solution doping function of nitrogen is lost. In addition, the nitrogen element is embedded into the glass phase structure of the glaze surface in the form of solid solution.

The above nitrogen doping cannot be achieved by directly calcining the glazed ceramic body in a nitrogen atmosphere after firing. Since nitrogen is an inert gas, it is difficult to achieve the above doping due to the poor activity of nitrogen atoms.

The present invention will be described in detail by way of examples. It is also to be understood that the following examples are illustrative of the present invention and are not to be construed as limiting the scope of the invention, and that certain insubstantial modifications and adaptations of the invention by those skilled in the art may be made in light of the above teachings. The specific process parameters and the like of the following examples are also only one example of suitable ranges, i.e., those skilled in the art can select the appropriate ranges through the description herein, and are not limited to the specific values exemplified below.

Example 1

The preparation method of the nitrogen-doped phosphate-based photocatalytic ceramic product comprises the following steps:

1) and preparing a material A. The materials are prepared according to the following mass ratio: SiO 2 ₂ 20％、AlPO ₄ 9％、Mn ₃ (PO ₄ ) ₂ 6％、Li ₃ PO ₄ 20％、Na ₃ PO ₄ 16％、K ₃ PO ₄ 29 percent. The raw materials are dry-mixed and ground, the mixture is obtained by sieving the raw materials with a 100-mesh sieve, the mixture is put into a crucible, the crucible is put into an electric furnace and is insulated for 20 minutes at 900 ℃, is insulated for 20 minutes at 1000 ℃ and is insulated for 20 minutes at 1500 ℃, and the frit is obtained by pouring the mixture into water and quenching the mixture after being taken out. Taking out the frits from water, drying and putting into a ball milling tank, wherein the grinding balls are prepared from 1/3 spherulites with the particle sizes of 5mm, 15mm and 20mm respectively in mass ratio, the rotating speed is 300 r/min, and the materials are controlled: the mass ratio of the grinding balls is 1:4, and the grinding balls are ground for 4 hoursSieving with a 300-mesh sieve, and drying for later use to be marked as material A.

2) And preparing a material B. 80 percent of material A, 10 percent of manganese tungstate and 10 percent of kaolin are mixed according to the mass ratio, the mixture is uniformly mixed and put in a ball milling tank, 1/3 are taken as grinding balls, the mass ratio of the ball stones with the particle sizes of 5mm, 15mm and 20mm is respectively, the rotating speed is 300 r/min, and the materials are controlled: the mass ratio of the grinding balls is 1:4, and after grinding for 6 hours, the grinding balls pass through a 300-mesh sieve, and the material is marked as material B.

3) And adding water into the material B, stirring and uniformly mixing to prepare glaze slurry, and adding ammonium polyacrylate as a dispersing agent, wherein the mass percentage of the water in the glaze slurry is 60%, and the mass percentage of the ammonium polyacrylate is 0.5%.

4) Glazing the prepared glaze slip on the surface of the ceramic, controlling the glazing thickness to be 0.5mm, drying at 80 ℃, firing by oxidizing flame of a roller kiln, keeping the temperature at 500 ℃ for 25 minutes, heating to 1250 ℃, keeping the temperature for 20 minutes, and controlling the firing period to be 60 minutes.

5) Spreading urea powder on the surface of the sintered ceramic body every 100cm ² 0.5g of urea powder is used on the surface of the ceramic body and calcined for 90 minutes at 400 ℃ in an inert atmosphere to obtain the nitrogen-doped phosphate-based photocatalytic ceramic product.

Example 2

1) and preparing a material A. The materials are prepared according to the following mass ratio: SiO 2 ₂ 20％、AlPO ₄ 9％、Mn ₃ (PO ₄ ) ₂ 6％、Li ₃ PO ₄ 20％、Na ₃ PO ₄ 16％、K ₃ PO ₄ 29 percent. The raw materials are dry-mixed and ground, the mixture is obtained by sieving the raw materials with a 100-mesh sieve, the mixture is put into a crucible, the crucible is put into an electric furnace and is insulated for 20 minutes at 900 ℃, is insulated for 20 minutes at 1000 ℃ and is insulated for 20 minutes at 1500 ℃, and the frit is obtained by pouring the mixture into water and quenching the mixture after being taken out. Taking out the frits from water, drying and putting into a ball milling tank, wherein the grinding balls are prepared from 1/3 spherulites with the particle sizes of 5mm, 15mm and 20mm respectively in mass ratio, the rotating speed is 300 r/min, and the materials are controlled: grinding balls with the mass ratio of 1:4 for 4 hours, sieving with a 300-mesh sieve, and drying for later use, wherein the material A is marked.

4) Glazing the prepared glaze slip on the surface of the ceramic, controlling the glazing thickness to be 0.5mm, drying at 80 ℃, firing by oxidizing flame in a roller kiln, keeping the temperature at 500 ℃ for 25 minutes at low temperature, heating to 1250 ℃, keeping the temperature for 20 minutes, and controlling the firing period to be 60 minutes.

5) Spreading urea powder on the surface of the sintered ceramic body every 100cm ² The surface of the ceramic body is calcined for 60 minutes at 600 ℃ in an inert atmosphere by using 1.5g of urea powder, so as to obtain the nitrogen-doped phosphate-based photocatalytic ceramic product.

Example 3

5) Spreading urea on the surface of the sintered ceramic body in a split manner, wherein each 100cm of urea is ² The surface of the ceramic body is calcined for 30 minutes at 800 ℃ in inert atmosphere by using 2.0g of urea powder, and the nitrogen-doped phosphate-based photocatalytic ceramic product is obtained.

Comparative example 1

Preparing a ceramic product:

3) And adding water into the material B, stirring and uniformly mixing to prepare a glaze slip, and adding ammonium polyacrylate serving as a dispersing agent, wherein the mass percentage of the water in the glaze slip is 60%, and the mass percentage of the ammonium polyacrylate is 0.5%.

4) Glazing the prepared glaze slip on the surface of the ceramic, controlling the glazing thickness to be 0.5mm, drying at 80 ℃, firing by oxidizing flame in a roller kiln, keeping the temperature at 500 ℃ for 25 minutes, heating to 1250 ℃, keeping the temperature for 20 minutes, and controlling the firing period to be 60 minutes to obtain the ceramic product.

XRD analysis of the glaze layer of the ceramic product of example 1 gave the results shown in FIG. 1. And comparing the PDF card, and finding that the PDF card contains manganese tungstate on the surface of the crystallized glaze ceramic product.

The ceramic products containing the crystalline glaze obtained in comparative example 1, example 2 and example 3 were subjected to photocatalytic tests. The photocatalytic performance of the samples was tested using a model BL-GHX-V photocatalyst (BILANS Biotech Co., Ltd.).

When the contaminant is formaldehyde, a ceramic tile of 6cm length by 1cm width is placed in a reactor with visible light irradiation (xenon lamp, 500W), and the lamp is turned on for light irradiation. The formaldehyde enters the reactor by blowing, the inlet formaldehyde concentration is measured by gas chromatography, and the degradation rate is calculated. The formaldehyde sampling time was 20 minutes each time. And measuring the concentration of formaldehyde under different degradation times to obtain a degradation curve. When the contaminant is a phenyl compound, the formaldehyde may be replaced with a phenyl compound.

FIG. 2 is per 100cm ² The surface of the ceramic body of (1) was coated with 0g of urea powder per 100cm (comparative example 1) ² The surface of the ceramic body (2) was coated with 0.5g of urea powder (example 1) per 100cm ² The surface of the ceramic body (2) was coated with 1.5g of urea powder (example 2) per 100cm ² The property pattern of photocatalytic degradation of formaldehyde using 2.0g of urea powder (example 3) on the surface of the ceramic body of (1).

FIG. 3 is per 100cm ² The surface of the ceramic body of (1) was coated with 0g of urea powder per 100cm (comparative example 1) ² Ceramic body of0.5g of urea powder (example 1) per 100cm was used for the surface ² The surface of the ceramic body (2) was coated with 1.5g of urea powder (example 2) per 100cm ² The performance chart of the photocatalytic degradation of a phenyl compound using 2.0g of urea powder (example 3) on the surface of the ceramic body (see (a) below).

It can be seen that the residual amount of the ceramic product without nitrogen doping to the formaldehyde and phenyl compound photocatalytic degradation for 4 hours is about 40%. The residual quantity of formaldehyde and phenyl compound degraded by the photocatalytic ceramic product after nitrogen doping is obviously reduced.

Claims

1. A method of preparing a nitrogen-doped phosphate-based photocatalytic ceramic product, comprising the steps of:

applying a glaze composition having a phosphate-based component that promotes preferential growth of the crystallographic structure orientation to the surface of the ceramic body; the glaze composition comprises the following raw materials: by mass percentage, 80-90% of powder A, 5-10% of manganese tungstate and 5-10% of kaolin; the powder A comprises the following raw materials: by mass percent, SiO ₂ 15～30%、AlPO ₄ 6～12%、Mn ₃ (PO ₄ ) ₂ 6～10%、Li ₃ PO ₄ 20～54%、Na ₃ PO ₄ 16～21%、K ₃ PO ₄ 20～29%；

Firing the ceramic body after applying the glaze composition;

and calcining the sintered ceramic body and the nitrogen-containing powder in an inert atmosphere to obtain the nitrogen-doped phosphate-based photocatalytic ceramic product.

2. The method according to claim 1, wherein the frit A is a frit; preferably, the preparation process of the frit comprises the following steps: uniformly mixing the raw materials of the powder A, then sieving the mixture at a first temperature for 10 to 20 minutes, continuously keeping the temperature at a second temperature for 10 to 20 minutes, keeping the temperature at a third temperature for 10 to 20 minutes, and then quenching and crushing the mixture to obtain a frit; wherein the first temperature is 600-900 ℃, the second temperature is 700-1000 ℃, and the third temperature is 1300-1500 ℃; more preferably, the second temperature is 50 to 200 ℃ higher than the first temperature.

3. The production method according to claim 2, wherein the glaze composition generates linear crystals that grow in a scattering orientation in a high-temperature firing environment.

4. The production method according to claim 3, wherein the linear crystal is a manganese tungstate crystal.

5. The production method according to claim 1, wherein the maximum firing temperature is 1100 to 1300 ℃ and the firing period is 60 to 170 minutes.

6. The method of claim 1, wherein the inert atmosphere for calcination is argon.

7. The method according to claim 1, wherein the calcination temperature is 400 to 800 ℃ and the calcination time is 30 to 90 minutes.

8. The method for preparing according to claim 1, wherein the glaze composition is applied to the surface of the ceramic body in the form of a glaze slip; the glaze slip comprises a dispersant and water in addition to the glaze composition; preferably, the water accounts for 40-60% of the mass of the glaze slip, and the dispersant accounts for 0.1-0.5% of the mass of the glaze slip.

9. The method according to claim 8, wherein the glaze slip forms a 0.05 to 0.3mm crystal glaze layer on the surface of the ceramic body.

10. Nitrogen-doped phosphate-based photocatalytic ceramic product obtained by the preparation method according to any one of claims 1 to 9.