CN112136829B

CN112136829B - Preparation of porous graphene-loaded weak photocatalyst-nano silver composite antiviral powder

Info

Publication number: CN112136829B
Application number: CN202010658986.7A
Authority: CN
Inventors: 张春明; 冉伟
Original assignee: Juzhi Suzhou Nano Technology Co ltd
Current assignee: Juzhi (Suzhou) Nano Technology Co.,Ltd.
Priority date: 2020-07-09
Filing date: 2020-07-09
Publication date: 2022-02-08
Anticipated expiration: 2040-07-09
Also published as: CN112136829A

Abstract

A preparation method of porous graphene loaded weak photocatalyst-nano silver composite antiviral powder comprises the steps of uniformly mixing a dispersing agent in an aqueous solution, prefabricating an expanded graphite premix, grinding by a sand mill, and preparing a nano graphene microchip solution with less than 10 layers under the synergistic effect of an intercalation agent, the dispersing agent, a wetting agent, a defoaming agent and grinding shearing force; doping titanium into zinc oxide crystal lattices by using a sol-gel method, forming an amorphous titanium dioxide coating layer on the surface of the titanium, preparing weak photocatalyst powder, and preparing weak photocatalyst dispersion liquid with the particle size of below 50 nanometers; then, preparing the silver compound into a metastable ultra-high concentration nano-complex silver solution by using a high-efficiency complexing agent; and finally, mixing the three solutions, performing ultrasonic treatment, irradiating and reducing the residual silver ions by the composite slurry under a constant-power fluorescent lamp, and then drying to finally obtain the porous graphene loaded weak photocatalyst-nano silver composite antiviral powder with excellent sterilization and virus killing capabilities.

Description

Preparation of porous graphene-loaded weak photocatalyst-nano silver composite antiviral powder

Technical Field

The invention belongs to the technical field of preparation of antiviral materials, and particularly relates to preparation of porous graphene loaded weak photocatalyst-nano silver composite antiviral powder.

Background

In recent years, researches report that the nano silver particles can effectively inhibit human immunodeficiency virus, hepatitis B virus, respiratory syncytial virus, herpes simplex virus-1, monkeypox virus and influenza virus. The nano silver has the advantages that the nano silver has extremely high antibacterial activity and does not generate drug resistance, and the nano silver has incomparable advantages compared with the traditional inorganic antibacterial agent. Although the antibacterial activity of nano silver is widely recognized, silver is a heavy metal and even in the form of nano, it may be slightly toxic by excessive contact with the human body. How to reduce the amount of silver and maintain its high antibacterial activity is an important issue in developing nano silver-based antibacterial agents. The immobilization of nanosilver on various substrates to form nanocomposites is an effective approach to solve this problem. The zinc oxide photocatalyst has good thermal stability and durability, particularly, zinc element is a trace element necessary for human body, has good compatibility with human body and low price, and in recent years, the nano-scale zinc oxide photocatalyst also has antibacterial and antiviral activity.

The domestic market is mainly made of organic antibacterial agents and a small amount of silver-loaded zirconium phosphate serving as an additive to prepare products with antibacterial performance, but the defects of low data, poor persistence and the like exist in the killing rate of the infectious viruses.

The invention mainly improves the antibacterial performance of the nano silver while reducing the use amount of the silver in design, and endows the product with extremely high virus killing rate. The material has good antibacterial and antiviral properties on drug-resistant bacteria under the synergistic action of silver ions released by nano silver and ROS (reactive oxygen species) excited by zinc oxide weak photocatalyst, and the graphene is used as a carrier, so that the continuous stability of sterilization and virus killing is improved under the condition that the ternary composite material slowly releases the silver ions for a long time.

In the synthesis of the composite antiviral material, a physical-chemical combination method is adopted to prepare a graphene carrier, a sol-gel method is utilized to prepare a zinc oxide weak photocatalyst material excited by visible light, a metastable ultra-high concentration nano-silver complex solution is prepared according to the characteristic of a high-efficiency complexing agent, and finally the three formula components are compounded, and the visible light catalysis characteristic of a weak photocatalyst is utilized to reduce nano-silver loaded on the surfaces of graphene and the weak photocatalyst in situ to form porous graphene loaded weak photocatalyst-nano silver composite antiviral powder. The product has very high sterilizing and virus killing effect only under visible light or weak light condition, and may be used widely in indoor and outdoor conditions.

Disclosure of Invention

The invention provides a preparation method of porous graphene loaded weak photocatalyst nano-silver composite antiviral powder, which comprises the following specific steps:

(1) preparing high-dispersion nano graphene microchip slurry: adding the expanded graphite into the water solution in which the dispersing agent, the defoaming agent and the wetting agent are pre-dissolved while stirring, uniformly stirring and mixing, and pre-dispersing by an emulsifying machine. And then grinding and dispersing by using a sand mill, and preparing the nano graphene microchip slurry with the diameter of about 1-5 microns and the thickness of less than or equal to 10 layers under the synergistic effect of the intercalation agent, the dispersing agent and the grinding shearing force.

(2) Preparing zinc oxide weak light photocatalyst slurry: adding a certain mass of zinc compound into ethanol, stirring, sequentially adding titanium compound, acetylacetone, ethylene diamine tetraacetic acid, citric acid and ammonia water, rapidly stirring at 80 ℃ to prepare transparent sol, presintering at 240 ℃ and calcining at 500 ℃ to obtain the amorphous titanium dioxide coated titanium doped zinc oxide weak photocatalyst powder. Then adding the weak light photocatalyst powder into a dispersing agent, a modifier, a defoaming agent and a wetting agent, and preparing the transparent slurry below 50 nanometers by using a nanometer grinding machine.

(3) Preparing a high-concentration metastable state transparent complex silver ion antibacterial agent: the silver compound is prepared into a metastable ultra-high concentration nano-complex silver solution by using a high-efficiency complexing agent and a nano-protective agent.

(4) Preparing the compound antiviral powder: and (3) mixing the nano graphene microchip slurry, the weak photocatalyst slurry and the metastable state transparent complex silver ion antibacterial agent respectively prepared in the steps (1) to (3) and carrying out ultrasonic treatment for 30min to enable the nano weak photocatalyst particles to be adsorbed on the graphene lamellar structure, and enable the complex silver ions to be adsorbed on the surfaces of the weak photocatalyst and the graphene to form the graphene composite antiviral precursor slurry. And then irradiating the graphene composite antiviral precursor slurry by using a constant-power fluorescent lamp, completely reducing the weak photocatalyst and silver ions on the surface of the graphene into nano silver particles, and drying to obtain the final porous graphene-loaded weak photocatalyst nano silver composite antiviral powder.

Preferably, the slurry in the step (1) is prepared from 0.3-1% (w/w) of expanded graphite, 0.3-1% (w/w) of dispersant CTAB, 0.01-0.03% (w/w) of defoaming agent, 0.05-0.1% (w/w) of wetting agent and the balance of deionized water. Wherein the defoaming agent is one of or the combination of DELTA-FC1501, DELTA-FC1503, DELTA-FC1522 and BYK028, and the wetting agent is one of or the combination of TEGO245 and TEGOwet 280.

Preferably, the step (1) is a sand mill grinding dispersion, wherein the filling rate of zirconium beads in the sand mill is 70-80%, the diameter of the zirconium beads is 0.3mm, and the grinding linear speed is 12 m/s. The intercalating agent is one or the combination of PVP, ferric trichloride, caprolactam, dodecylbenzene sulfonic acid and poly dimethyl diallyl ammonium chloride, and the proportion is 0.1-0.3% (w/w).

Preferably, the synthetic ratio in the step (2) is 20-40% (w/w) of zinc compound, 0.2-1% (w/w) of titanium compound, 3-5% (w/w) of acetylacetone, 3-5% (w/w) of ethylene diamine tetraacetic acid, 1-2% (w/w) of citric acid, and the balance of absolute ethyl alcohol, and the pH value is adjusted to 8-10 by ammonia water. The titanium compound is one or the combination of titanium tetrachloride, n-butyl titanate, isopropyl titanate, isooctyl titanate and tetraethyl titanate.

Preferably, the mixture ratio of the weak light photocatalyst slurry in the step (2) is 5-50% (w/w) of weak light photocatalyst powder, 1.5-10% (w/w) of sodium polyacrylate dispersant, 1.5-6% (w/w) of polyvinylpyrrolidone modifier, 0.01-0.03% (w/w) of defoaming agent and 0.5-2% (w/w) of wetting agent. The defoaming agent is BYK011 or BYK028 or a combination thereof, the wetting agent is TEGO260 or TEGOwet505 or a combination thereof, the filling rate of zirconium beads in the sand mill is 70-80%, the diameter of the selected zirconium beads is 0.05mm, and the grinding linear speed is 10 m/s.

Preferably, in the step (3), the silver compound accounts for 3-10% (w/w), the EDTA complexing agent accounts for 3-10% (w/w), and the nano protective agent accounts for 1.5-5% (w/w). Wherein the silver compound is one or the combination of silver acetate, silver oxide and silver nitrate, the nano protective agent is one or the combination of block copolymers P123 and F127, and the concentration of the complex silver ions is 300-15000 ppm.

Preferably, the ratio in the step (4) is that the graphene slurry: weak light photocatalyst slurry: the complex silver is 1 (1-2) and (0.5-1) (w/w). The constant power of the fluorescent lamp is 20W, and the irradiation time under the fluorescent lamp is 30-60 min.

Compared with the prior art, the composite antiviral material prepared by the method has the following beneficial effects:

(1) the antibacterial and bactericidal composition has excellent antibacterial and bactericidal performance and efficient antiviral and bactericidal performance. The application field and range of the material can be greatly expanded, and the material has higher sterilization rate and virus killing rate than pure nano silver and zinc oxide.

(2) In order to improve the sterilization and disinfection performance under extreme conditions, the zinc oxide weak photocatalyst material excited under visible light is prepared by adopting a solvent gel method and an element doping mode, so that the sterilization and disinfection time can be greatly shortened, and a sterile and non-toxic environment is created.

(3) The carrier characteristic of the graphene can improve the contact type sterilization and disinfection capability of the nano-silver and can also improve the photocatalytic sterilization and disinfection performance, so that the ternary composite antiviral powder has high sterilization and disinfection efficiency.

Drawings

Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings:

FIG. 1 is an SEM image of the product of example 1 of the present invention;

FIG. 2 is an SEM image of the product of example 4 of the present invention.

Detailed Description

The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that variations and modifications can be made by persons skilled in the art without departing from the spirit of the invention. All falling within the scope of the present invention.

The first embodiment is as follows:

preparing high-dispersion nano graphene microchip slurry: adding 3g of expanded graphite into 992.4g of aqueous solution, adding into the aqueous solution pre-dissolved with 3g of dispersing agent CTAB, 0.1g of defoaming agent DELTA-FC1501 and 0.5g of wetting agent TEGO245 while stirring, uniformly stirring and pre-dispersing by an emulsifying machine. And then grinding and dispersing by a sand mill, wherein the filling rate of zirconium beads is 70%, the diameter of the zirconium beads is selected to be 0.3mm, the grinding linear speed is 12m/s, and nano graphene microchip slurry with the diameter of about 5 microns and the thickness of less than or equal to 10 layers is prepared under the synergistic effect of 1g of intercalation agent PVP, dispersing agent and grinding shearing force.

Preparing zinc oxide weak light photocatalyst slurry: adding 20g of zinc nitrate into 72.8g of ethanol, stirring, sequentially adding 0.2g of n-butyl titanate, 3g of acetylacetone, 3g of ethylene diamine tetraacetic acid and 1g of citric acid, adjusting the pH to 8 by using ammonia water, quickly stirring at 80 ℃ to prepare transparent sol, presintering at 240 ℃, and calcining at 500 ℃ to obtain the amorphous titanium dioxide coated titanium-doped zinc oxide weak photocatalyst powder. Then 50g of weak photocatalyst powder, 914.9g of deionized water, 15g of sodium polyacrylate dispersant, 15g of polyvinylpyrrolidone modifier, 0.1g of defoaming agent BYK011 and 5g of wetting agent TEGO260 are prepared into transparent slurry below 50 nanometers by using a nanometer grinder. The filling rate of zirconium beads in the sand mill is 70 percent, the diameter of the zirconium beads is 0.05mm, and the grinding linear velocity is 10 m/s.

Preparing a high-concentration metastable state transparent complex silver ion antibacterial agent: 30g of silver acetate is prepared into a metastable ultra-high concentration transparent nano-silver complexing solution by using 30g of EDTA (ethylene diamine tetraacetic acid) and 15g of protective agent P123, and deionized water is added to adjust the concentration of complexing silver ions to 300 ppm.

Preparing the compound antiviral powder: mixing 1kg of nano graphene microchip slurry prepared in the steps, 1kg of weak photocatalyst slurry and 0.5kg of metastable state transparent complex silver ion antibacterial agent, and carrying out ultrasonic treatment for 30min to enable nano weak photocatalyst particles to be adsorbed on a graphene lamellar structure, and enable complex silver ions to be adsorbed on the surfaces of the weak photocatalyst and the graphene to form graphene composite antiviral precursor slurry. And then irradiating the graphene composite antiviral precursor slurry by using a 20W constant-power fluorescent lamp for 30min, completely reducing the weak photocatalyst and silver ions on the surface of the graphene into nano silver particles, and drying to obtain the final porous graphene loaded weak photocatalyst nano silver composite antiviral powder. FIG. 1 is an SEM image of the product of this example.

Example two:

preparing high-dispersion nano graphene microchip slurry: adding 5g of expanded graphite into 992.4g of aqueous solution, adding into the aqueous solution pre-dissolved with 5g of dispersing agent CTAB, 0.15g of defoaming agent DELTA-FC1503 and 0.6g of wetting agent TEGO wet280 while stirring, uniformly stirring and pre-dispersing by an emulsifying machine. And then grinding and dispersing by a sand mill, wherein the filling rate of zirconium beads is 75%, the diameter of the zirconium beads is 0.3mm, the grinding linear speed is 12m/s, and under the synergistic effect of 2g of intercalation agent dodecylbenzene sulfonic acid, a dispersing agent and grinding shearing force, nano graphene micro-sheet slurry with the diameter of about 3 microns and the thickness of less than or equal to 10 layers is prepared.

Preparing zinc oxide weak light photocatalyst slurry: adding 30g of zinc oxalate into 60g of ethanol, stirring, sequentially adding 0.5g of titanium tetrachloride, 4g of acetylacetone, 4g of ethylene diamine tetraacetic acid and 1.5g of citric acid, adjusting the pH to 9 by using ammonia water, quickly stirring at 80 ℃ to prepare transparent sol, presintering at 240 ℃ and calcining at 500 ℃ to obtain the amorphous titanium dioxide coated titanium-doped zinc oxide weak photocatalyst powder. Then 100g of weak photocatalyst powder, 839.85g of deionized water, 25g of sodium polyacrylate dispersant, 25g of polyvinylpyrrolidone modifier, 0.15g of defoaming agent BYK028 and 10g of wetting agent TEGO260 are prepared into transparent slurry below 50 nanometers by using a nanometer grinder. The filling rate of zirconium beads in the sand mill is 75 percent, the diameter of the zirconium beads is 0.05mm, and the grinding linear velocity is 10 m/s.

Preparing a high-concentration metastable state transparent complex silver ion antibacterial agent: 45g of silver oxide is prepared into a metastable ultra-high concentration transparent nano-silver complexing solution by using 45g of EDTA (ethylene diamine tetraacetic acid) and 22g of protective agent P123, and deionized water is added to adjust the concentration of complexing silver ions to 2000 ppm.

Preparing the compound antiviral powder: mixing 1kg of nano graphene microchip slurry prepared in the steps, 1.5kg of weak photocatalyst slurry and 0.8kg of metastable transparent complex silver ion antibacterial agent, and carrying out ultrasonic treatment for 30min to enable nano weak photocatalyst particles to be adsorbed on a graphene lamellar structure, and enable complex silver ions to be adsorbed on the surfaces of the weak photocatalyst and the graphene to form graphene composite antiviral precursor slurry. And then irradiating the graphene composite antiviral precursor slurry by using a 20W constant-power fluorescent lamp for 40min, completely reducing the weak photocatalyst and silver ions on the surface of the graphene into nano silver particles, and drying to obtain the final porous graphene loaded weak photocatalyst nano silver composite antiviral powder.

Example three:

preparing high-dispersion nano graphene microchip slurry: adding 8g of expanded graphite into 983g of aqueous solution, adding into the aqueous solution pre-dissolved with 8g of dispersing agent CTAB, 0.2g of defoaming agent DELTA-FC1522 and 0.8g of wetting agent TEGO wet280 while stirring, uniformly stirring and pre-dispersing by an emulsifying machine. And then grinding and dispersing by a sand mill, wherein the filling rate of zirconium beads is 80%, the diameter of the zirconium beads is selected to be 0.3mm, the grinding linear speed is 12m/s, and nano graphene microchip slurry with the diameter of about 2 microns and the thickness of less than or equal to 10 layers is prepared under the synergistic effect of 3g of intercalation agent ferric trichloride, dispersing agent and grinding shearing force.

Preparing zinc oxide weak light photocatalyst slurry: adding 40g of zinc stearate into 47.2g of ethanol, stirring, sequentially adding 0.8g of isopropyl titanate, 5g of acetylacetone, 5g of ethylene diamine tetraacetic acid and 2g of citric acid, adjusting the pH to 10 by using ammonia water, quickly stirring at 80 ℃ to prepare transparent sol, presintering at 240 ℃ and calcining at 500 ℃ to obtain the amorphous titanium dioxide coated titanium-doped zinc oxide weak photocatalyst powder. 500g of weak photocatalyst powder, 319.7g of deionized water, 100g of sodium polyacrylate dispersant, 60g of polyvinylpyrrolidone modifier, 0.3g of defoaming agent BYK028 and 20g of wetting agent TEGOwet505 are prepared into transparent slurry with the particle size of less than 50 nanometers by using a nanometer grinder. The filling rate of zirconium beads in the sand mill is 80 percent, the diameter of the zirconium beads is 0.05mm, and the grinding linear velocity is 10 m/s.

Preparing a high-concentration metastable state transparent complex silver ion antibacterial agent: 100g of silver nitrate is prepared into a metastable ultra-high concentration transparent nano-complex silver solution by using 100g of EDTA (ethylene diamine tetraacetic acid) and 30g of protective agent P127, and deionized water is added to adjust the concentration of complex silver ions to 10000 ppm.

Preparing the compound antiviral powder: mixing 1kg of nano graphene microchip slurry prepared in the above steps, 2kg of weak photocatalyst slurry and 1kg of metastable state transparent complex silver ion antibacterial agent, and performing ultrasonic treatment for 30min to enable nano weak photocatalyst particles to be adsorbed on a graphene lamellar structure, and enable complex silver ions to be adsorbed on the surfaces of the weak photocatalyst and the graphene to form graphene composite antiviral precursor slurry. And then irradiating the graphene composite antiviral precursor slurry by using a 20W constant-power fluorescent lamp for 60min, completely reducing the weak photocatalyst and silver ions on the surface of the graphene into nano silver particles, and drying to obtain the final porous graphene loaded weak photocatalyst nano silver composite antiviral powder.

Example four:

preparing high-dispersion nano graphene microchip slurry: adding 10g of expanded graphite into 983g of aqueous solution, adding the expanded graphite into the aqueous solution pre-dissolved with 10g of dispersing agent CTAB, 0.3g of defoaming agent DELTA-FC1522 and 1g of wetting agent TEGO wet280 while stirring, uniformly stirring and pre-dispersing by an emulsifying machine. And then grinding and dispersing by a sand mill, wherein the filling rate of zirconium beads is 80%, the diameter of the zirconium beads is selected to be 0.3mm, the grinding linear speed is 12m/s, and under the synergistic action of 3g of intercalation agent poly dimethyl diallyl ammonium chloride, a dispersing agent and grinding shearing force, nano graphene microchip slurry with the diameter of about 1 micron and the thickness of less than or equal to 10 layers is prepared.

Preparing zinc oxide weak light photocatalyst slurry: adding 40g of zinc bicarbonate into 47g of ethanol, stirring, sequentially adding 1g of tetraethyl titanate, 5g of acetylacetone, 5g of ethylene diamine tetraacetic acid and 2g of citric acid, adjusting the pH to 10 by using ammonia water, quickly stirring at 80 ℃ to prepare transparent sol, presintering at 240 ℃ and calcining at 500 ℃ to obtain the amorphous titanium dioxide coated titanium-doped zinc oxide weak photocatalyst powder. 500g of weak photocatalyst powder, 319.7g of deionized water, 100g of sodium polyacrylate dispersant, 60g of polyvinylpyrrolidone modifier, 0.3g of defoaming agent BYK028 and 20g of wetting agent TEGOwet505 are prepared into transparent slurry with the particle size of less than 50 nanometers by using a nanometer grinder. The filling rate of zirconium beads in the sand mill is 80 percent, the diameter of the zirconium beads is 0.05mm, and the grinding linear velocity is 10 m/s.

Preparing a high-concentration metastable state transparent complex silver ion antibacterial agent: 100g of silver nitrate is prepared into a metastable ultra-high concentration transparent nano-silver complexing solution by using 100g of EDTA (ethylene diamine tetraacetic acid) and 50g of protective agent P127, and deionized water is added to adjust the concentration of the complexing silver ions to 15000 ppm.

Preparing the compound antiviral powder: mixing 1kg of nano graphene microchip slurry prepared in the above steps, 2kg of weak photocatalyst slurry and 1kg of metastable state transparent complex silver ion antibacterial agent, and performing ultrasonic treatment for 30min to enable nano weak photocatalyst particles to be adsorbed on a graphene lamellar structure, and enable complex silver ions to be adsorbed on the surfaces of the weak photocatalyst and the graphene to form graphene composite antiviral precursor slurry. And then irradiating the graphene composite antiviral precursor slurry by using a 20W constant-power fluorescent lamp for 60min, completely reducing the weak photocatalyst and silver ions on the surface of the graphene into nano silver particles, and drying to obtain the final porous graphene loaded weak photocatalyst nano silver composite antiviral powder. FIG. 2 is an SEM image of the product of this example. Table 1 shows the bactericidal and virucidal rate data for the product of this example in a 1% aqueous solution.

TABLE 1 Sterilization and virucidal Rate data for the product of this example in 1% aqueous solution

Claims

1. A preparation method of porous graphene loaded weak photocatalyst-nano silver composite antiviral powder is characterized by comprising the following specific steps:

(1) preparing high-dispersion nano graphene microchip slurry: adding expanded graphite into a water solution in which a dispersing agent, a defoaming agent and a wetting agent are dissolved in advance while stirring, uniformly stirring, pre-dispersing by an emulsifying machine, grinding and dispersing by a sand mill, and preparing nano graphene microchip slurry with the diameter of about 1-5 microns and the thickness of less than or equal to 10 layers under the synergistic effect of an intercalation agent, the dispersing agent and grinding shearing force;

(2) preparing zinc oxide weak light photocatalyst slurry: adding a certain mass of zinc compound into ethanol, stirring, sequentially adding a titanium compound, acetylacetone, ethylene diamine tetraacetic acid, citric acid and ammonia water, rapidly stirring at 80 ℃ to prepare transparent sol, presintering at 240 ℃, calcining at 500 ℃ to obtain amorphous titanium dioxide coated titanium doped zinc oxide weak photocatalyst powder, adding a sodium polyacrylate dispersant, a polyvinylpyrrolidone modifier, a defoaming agent and a wetting agent into the weak photocatalyst powder, and preparing into transparent slurry below 50 nanometers by using a nanometer grinder;

(3) preparing a high-concentration metastable state transparent complex silver ion antibacterial agent: preparing a silver compound into a metastable ultra-high concentration nano-complex silver solution by using a high-efficiency complexing agent and a nano protective agent;

(4) preparing the compound antiviral powder: mixing the nano graphene microchip slurry, the weak photocatalyst slurry and the metastable state transparent complex silver ion antibacterial agent which are respectively prepared in the steps (1) to (3) and performing ultrasonic treatment for 30min to enable the nano-scale weak photocatalyst particles to be adsorbed on a graphene lamellar structure, and enable complex silver ions to be adsorbed on the weak photocatalyst and the graphene surface at the same time to form graphene composite antiviral precursor slurry, then irradiating the graphene composite antiviral precursor slurry by using a constant-power fluorescent lamp, completely reducing the weak photocatalyst and the silver ions on the graphene surface into nano silver particles, and drying to obtain the final porous graphene loaded weak photocatalyst nano silver composite antiviral powder.

2. The preparation method of the porous graphene-loaded weak photocatalyst-nano silver composite antiviral powder as claimed in claim 1, wherein the slurry in the step (1) is prepared from 0.3-1% (w/w) of expanded graphite, 0.3-1% (w/w) of a dispersant CTAB, 0.01-0.03% (w/w) of an antifoaming agent, 0.05-0.1% (w/w) of a wetting agent, and the balance of deionized water, wherein the antifoaming agent is one or a combination of DELTA-FC1501, DELTA-FC1503, DELTA-FC1522 and BYK028, and the wetting agent is one or a combination of TEGO245 and TEGOwet 280.

3. The method for preparing the porous graphene-loaded weak photocatalyst-nano silver composite antiviral powder according to claim 1, wherein the grinding machine in the step (1) is used for grinding and dispersing, wherein the filling rate of zirconium beads in the grinding machine is 70-80%, the diameter of the zirconium beads is 0.3mm, the grinding linear speed is 12m/s, the intercalator is one or a combination of PVP, ferric trichloride, caprolactam, dodecylbenzene sulfonic acid and poly dimethyl diallyl ammonium chloride, and the proportioning composition is 0.1-0.3% (w/w).

4. The preparation method of the porous graphene-loaded weak photocatalyst-nano silver composite antiviral powder as claimed in claim 1, wherein the synthesis ratio in the step (2) is 20-40% (w/w) of a zinc compound, 0.2-1% (w/w) of a titanium compound, 3-5% (w/w) of acetylacetone, 3-5% (w/w) of ethylenediaminetetraacetic acid, 1-2% (w/w) of citric acid, and the balance of anhydrous ethanol, and the pH is adjusted to 8-10 with ammonia water, wherein the zinc compound is one or a combination of zinc nitrate, zinc acetate, zinc stearate, zinc oxalate and zinc bicarbonate, and the titanium compound is one or a combination of titanium tetrachloride, n-butyl titanate, isopropyl titanate, isooctyl titanate and tetraethyl titanate.

5. The method for preparing porous graphene-loaded weak photocatalyst-nano silver composite antiviral powder as claimed in claim 1, wherein the ratio of the weak photocatalyst slurry in the step (2) is 5-50% (w/w), 1.5-10% (w/w) of sodium polyacrylate dispersant, 1.5-6% (w/w) of polyvinylpyrrolidone modifier, 0.01-0.03% (w/w) of defoamer, and 0.5-2% (w/w) of wetting agent, wherein the defoamer is one or a combination of BYK011 and BYK028, the wetting agent is one or a combination of TEGO260 and TEGOwet505, wherein the filling rate of zirconium beads in a sand mill is 70-80%, the diameter of zirconium beads is selected to be 0.05mm, and the grinding linear speed is 10 m/s.

6. The method for preparing porous graphene-loaded weak photocatalyst-nano silver composite antiviral powder as claimed in claim 1, wherein in the step (3), the silver compound is 3-10% (w/w), the EDTA complexing agent is 3-10% (w/w), and the nano protective agent is 1.5-5% (w/w), wherein the silver compound is one or a combination of silver acetate, silver oxide and silver nitrate, the nano protective agent is one or a combination of block copolymers P123 and F127, and the concentration of the complex silver ions is 300-15000 ppm.

7. The method for preparing the porous graphene-loaded weak photocatalyst-nano silver composite antiviral powder according to claim 1, wherein the ratio in the step (4) is as follows: weak light photocatalyst slurry: the silver complex =1 (1-2) and (0.5-1) (W/W), the constant power of the fluorescent lamp is 20W, and the irradiation time under the fluorescent lamp is 30-60 min.