CN111266099A - Series of inorganic antibacterial mildew-proof monatomic catalysts and preparation method thereof - Google Patents

Abstract

The invention belongs to the field of catalysts, and particularly relates to a series of inorganic antibacterial and mildewproof monatomic catalysts and a preparation method thereof. The invention discloses a series of inorganic antibacterial mildew-proof monatomic catalysts, wherein each monatomic catalyst consists of a carrier and transition metal, and the carrier is any one of an inorganic calcium-based carrier, an inorganic silicon-based carrier, an inorganic aluminum-based carrier and an inorganic titanium-based carrier; the transition metal is selected from one or more of a first transition metal and a second transition metal; the transition metal is anchored in the form of a single atom at a defect site on the surface of the support. The catalyst can efficiently activate oxygen in air or water without other auxiliary conditions, generate active oxygen species, oxidize cell membranes, proteins, genetic substances and the like of bacteria, and kill the bacteria. The monatomic catalyst has a stable structure, is not consumed, can be repeatedly used, has no pollution to the environment, and has no side effect on organisms.

Description

A series of inorganic antibacterial and antifungal single-atom catalysts and preparation method thereof

technical field

The invention belongs to the field of catalysts, and in particular relates to a series of inorganic antibacterial and mildew-proof single-atom catalysts and a preparation method thereof.

Background technique

At present, the global environmental pollution problem is becoming more and more serious, endangering the healthy survival and development of human beings, and the pollution control problem has become imminent. Environmental pollution is mainly divided into air pollution, soil pollution and water pollution. Microorganisms such as bacteria and viruses not only consume a large amount of energy and resources, but also seriously endanger people's health. Therefore, it is of great significance to develop new, practical and long-acting broad-spectrum antibacterial and antifungal materials.

In recent years, single-atom catalysis has rapidly developed into the most popular frontier field in the field of catalysis science. Compared with nano-scale catalysts, single-atom catalysts use a single atom as the active center, and the utilization rate of catalytic active materials reaches 100%, which greatly reduces the cost of catalysts. The single-atom catalyst has clear and uniform active sites, high activity and high selectivity. Single-atom catalysis was successfully selected as one of the top ten research achievements in the field of chemistry and chemical engineering by the American Chemical Society in 2016. This year, it was successfully selected as one of the top 20 scientific and technological problems released by the 2019 China Association for Science and Technology Annual Conference. It is a popular research field in my country and the world.

Due to the wide range of applications of single-atom catalysis, different applications put forward different requirements for it, and the existing single-atom catalysts are difficult to meet the requirements of antibacterial and mildew applications. Therefore, exploring and developing single-atom catalysts with antibacterial and anti-mildew properties Significance.

SUMMARY OF THE INVENTION

One of the objectives of the present invention is to provide a series of single-atom catalysts for antibacterial and mildew prevention in view of the deficiencies of the prior art.

In order to achieve this purpose, the present invention discloses a series of inorganic antibacterial and mildew-proof single-atom catalysts. The single-atom catalyst is composed of a carrier and a transition metal. any one of the carrier and the inorganic titanium-based carrier; the transition metal is selected from one or more of the first transition metal to the second transition metal; the transition metal is anchored on the surface of the carrier in the form of a single atom defect site.

Preferably, the inorganic calcium-based carrier is any one of calcium carbonate, calcium phosphate, calcium silicate, and hydroxyapatite.

Preferably, the inorganic silicon-based carrier is any one of diatomite, kaolin, nano-silica, and fumed silica, the chemical composition of the diatomite is mainly SiO2, and the crystal of the kaolin is The chemical formula is 2SiO2·Al2O3·2H2O.

Preferably, the inorganic aluminum-based carrier is any one of alumina and kaolin.

Preferably, the inorganic titanium-based carrier is any one of titanium dioxide, nano-titanium dioxide, and Degussa P25.

Preferably, the transition metal is selected from one or more of Fe, Co, Ni, Cu, Ag, Mn and Zn, and the mass ratio of the transition metal and the carrier contained in the catalyst is 1:20～1: 200.

Further, the present invention also discloses a preparation method of this antibacterial and anti-mildew single-atom catalyst. The specific technical scheme is as follows: a series of inorganic antibacterial and anti-mildew single-atom catalysts include the following steps:

1) ultrasonically, stirring and mixing the transition metal salt solution and the carrier;

2) removing the solvent of the product obtained in step 1), and grinding to obtain a solid powder;

3) The solid powder obtained in step 2) is subjected to heat treatment, cooled and then ground to obtain the desired catalyst.

Preferably, the concentration of the metal salt solution in step 1) is 5-200 g/L, the metal salt is any one of chloride, nitrate and sulfate, and the solvent of the solution is water or an organic solution , any one of the water-organic mixed solvent, and the stirring time is 12-48h.

Preferably, the heating treatment in step 3) is heating at a temperature of 50-1000° C. for 2-4 hours in an air or argon atmosphere, and the grinding time is 20-40 minutes.

Compared with traditional antibacterial materials, single-atom catalysts have more excellent antibacterial properties. The single-atom catalyst does not require any auxiliary conditions, and can efficiently activate the oxygen in the air to generate reactive oxygen species, and oxidize the bacterial membrane, protein, genetic material, etc. of bacteria to kill cells. The single-atom catalyst has a stable structure and can be used repeatedly. No pollution to the environment and no side effects to the organism.

Description of drawings

Figure 1 shows the antibacterial effect of different doses of catalysts on Staphylococcus aureus;

Figure 2 shows the antibacterial effect of different doses of catalysts on Escherichia coli;

Figure 3 shows the antibacterial effect of different doses of catalysts on Salmonella;

Figure 4 shows the antibacterial effects of different series of inorganic carrier single-atom catalysts (catalyst content is 2000ppm) on Staphylococcus aureus, Escherichia coli, and Salmonella;

Figure 5 shows the broad-spectrum antibacterial effect of different series of inorganic supported single-atom catalysts (catalyst content is 2000ppm) in practical application scenarios;

Figure 6 shows the antibacterial performance comparison and time curve of single-atom catalyst, potassium hydrogen persulfate (DuPont Vico) and benzalkonium chloride (Zunuo, New Zealand).

Detailed ways

The present invention will be described in further detail below with reference to specific examples, but the embodiments of the present invention are not limited to the scope represented by the examples. These examples are only used to illustrate the present invention, but not to limit the scope of the present invention. In addition, after reading the content of the present invention, those skilled in the art can make various modifications to the present invention, and these equivalent changes also fall within the scope defined by the appended claims of the present invention.

Example 1

Step 1, add 5g/L ferric chloride aqueous solution into diatomite (inorganic silicon-based carrier), wherein the mass ratio of transition metal to carrier is 1:20, the obtained solution is ultrasonically dispersed uniformly for 30min under the condition of 100kHz, and then Stir the mixed solution at 100r/min for 12h;

Step 2, the mixed solution obtained in step 1 is heated to the boiling point of water, volatilized at high temperature, evaporated to dryness, and fully ground with a ball mill for 0.5 hours at a rotational speed of 50 r/min to obtain solid powder;

In step 3, the solid powder obtained in step 2 is heated for 2 hours in an air atmosphere and at a temperature of 400 ° C, cooled to room temperature, and ground in a ball mill for 20 minutes at a rotational speed of 50 r/min to obtain the desired catalyst. The transition metals contained are anchored to defect sites on the surface of the support in the form of single atoms.

Example 2

Step 1, add the aqueous solution of 10g/L cupric chloride into calcium carbonate (inorganic calcium-based carrier), wherein the mass ratio of transition metal to carrier is 1:50, the obtained solution is ultrasonically dispersed uniformly for 30min under the condition of 100kHz, and then The mixed solution was stirred at 150r/min for 20h;

Step 2, the mixed solution obtained in step 1 is heated to the boiling point of water, volatilized at high temperature, evaporated to dryness, and fully ground with a ball mill at 100 r/min for 1 hour to obtain solid powder;

In step 3, the solid powder obtained in step 2 is heated for 3 hours in an air atmosphere and at a temperature of 200 ° C, cooled to room temperature, and ground in a ball mill for 30 minutes at a rotational speed of 100 r/min to obtain the desired catalyst. The transition metals contained are anchored to defect sites on the surface of the support in the form of single atoms.

Example 3

Step 1, adding 200g/L of cobalt chloride in water and ethanol (volume ratio of 1:1) solution into alumina (inorganic aluminum-based carrier), wherein the mass ratio of transition metal to carrier is 1:200, and the resulting solution is 100kHz Under the condition of ultrasonic 30min to disperse uniformly, then the mixed solution was stirred at 200r/min for 48h;

Step 2, the mixed solution obtained in step 1 is heated to the boiling point of the mixed solution, volatilized at high temperature, evaporated to dryness, and fully ground with a ball mill at 500 r/min for 3 hours to obtain solid powder;

In step 3, the solid powder obtained in step 2 is heated for 4 hours under an argon atmosphere and a temperature of 800 ° C, cooled to room temperature, and ground in a ball mill for 40 minutes at a rotational speed of 500 r/min to obtain the desired catalyst. The transition metals contained in the catalyst are anchored to defect sites on the surface of the support in the form of single atoms.

Example 4

Step 1, adding the aqueous solution of 10g/L nickel chloride and 10g/L zinc chloride into titanium dioxide (inorganic titanium-based carrier), wherein the mass ratio of transition metal to carrier is 1:30, and the mass ratio of the two transition metals is 1:30. For 1:1, the obtained solution was uniformly dispersed by ultrasound for 30 min under the condition of 100 kHz, and then the mixed solution was stirred at 100 r/min for 48 h;

Step 2, the mixed solution obtained in step 1 is heated to the boiling point of water, volatilized at high temperature, evaporated to dryness, and fully ground with a ball mill at a rotational speed of 300 r/min for 2 hours to obtain solid powder;

In step 3, the solid powder obtained in step 2 is heated for 2.5 hours in an air atmosphere and at a temperature of 600 ° C, cooled to room temperature, and ground in a ball mill for 25 minutes at a rotational speed of 200 r/min to obtain the desired catalyst. The transition metals contained in the catalyst are anchored to defect sites on the surface of the support in the form of single atoms.

Example 5

Step 1, adding the aqueous solution of 50g/L zinc nitrate and 50g/L ferric nitrate to calcium silicate (inorganic calcium-based carrier), wherein the mass ratio of transition metal to carrier is 1:60, and the mass ratio of the two transition metals is 1:2, under the condition of 100kHz, the obtained solution was ultrasonically dispersed for 30min, and then the mixed solution was stirred at 150r/min for 25h;

Step 2, the mixed solution obtained in step 1 is heated to the boiling point of water, volatilized at high temperature, evaporated to dryness, and fully ground with a ball mill at 250r/min for 1.5 hours to obtain solid powder;

In step 3, the solid powder obtained in step 2 is heated for 3 hours in an air atmosphere and a temperature of 300 ° C, cooled to room temperature, and ground in a ball mill for 35 minutes at a rotational speed of 300 r/min to obtain the desired catalyst. The transition metals contained are anchored to defect sites on the surface of the support in the form of single atoms.

Example 6

Step 1, adding the aqueous solution of 50g/L cobalt chloride, 50g/L cupric chloride, and 100g/L silver nitrate into nano-silicon oxide (inorganic silicon-based carrier), wherein the mass ratio of transition metal to carrier is 1:20, The mass ratio of cobalt, copper, and silver is 1:2:3, and the obtained solution is uniformly dispersed by ultrasound for 30 minutes under the condition of 100 kHz, and then the mixed solution is stirred at 200 r/min for 12 hours;

Step 2, the mixed solution obtained in step 1 is heated to the boiling point of water, volatilized at high temperature, evaporated to dryness, and fully ground with a ball mill for 0.5 hours at a rotational speed of 500 r/min to obtain solid powder;

In step 3, the solid powder obtained in step 2 is heated for 2 hours under an argon atmosphere and a temperature of 700° C., cooled to room temperature, and ground in a ball mill for 20 minutes at a rotational speed of 500 r/min to obtain the desired catalyst. The transition metals contained in the catalyst are anchored to defect sites on the surface of the support in the form of single atoms.

Example 7

Step 1, adding 150g/L ferric sulfate and 150g/L copper sulfate aqueous solution to kaolin (inorganic aluminum-based carrier), wherein the mass ratio of transition metal to carrier is 1:150, and the mass ratio of two transition metals is 1:1 , under the condition of 100kHz ultrasonic wave for 30min to disperse the obtained solution uniformly, and then stir the mixed solution at 100r/min for 48h;

Step 2, the mixed solution obtained in step 1 is heated to the boiling point of water, volatilized at high temperature, evaporated to dryness, and fully ground with a ball mill at 400 r/min for 3 hours to obtain solid powder;

In step 3, the solid powder obtained in step 2 is heated for 2 hours under an argon atmosphere and a temperature of 50 ° C, cooled to room temperature, and ground in a ball mill for 40 minutes at a rotational speed of 400 r/min to obtain the desired catalyst. The transition metals contained in the catalyst are anchored to defect sites on the surface of the support in the form of single atoms.

Example 8

Step 1, adding 150g/L ferric chloride, 160g/L cupric chloride water and ethanol solution into nano-titanium dioxide (inorganic titanium-based carrier), wherein the mass ratio of transition metal to carrier is 1:200, and the mass ratio of the two transition metals is 1:200. The mass ratio is 1:1, and the volume ratio of water and ethanol is 1:1. The obtained solution is uniformly dispersed by ultrasonic for 30min under the condition of 100kHz, and then the mixed solution is stirred at 100r/min for 48h;

Step 2, heating the mixed solution obtained in step 1 to the boiling point of the mixed solvent, volatilizing at high temperature, evaporating the solvent to dryness, and fully grinding with a ball mill at 500 r/min for 3 hours to obtain solid powder;

In step 3, the solid powder obtained in step 2 is heated for 4 hours under an argon atmosphere and a temperature of 750 ° C, cooled to room temperature, and ground in a ball mill for 40 minutes at a rotational speed of 500 r/min to obtain the desired catalyst. The transition metals contained in the catalyst are anchored to defect sites on the surface of the support in the form of single atoms.

Example 9

Step 1, add 200g/L zinc nitrate methanol solution into hydroxyapatite (inorganic calcium-based carrier), wherein the mass ratio of transition metal to carrier is 1:200, and the obtained solution is uniformly dispersed by ultrasound for 30min under the condition of 100kHz, and then The mixed solution was stirred at 200r/min for 48h;

Step 2, the mixed solution obtained in step 1 is heated to the boiling point of methanol, volatilized at high temperature, evaporated to dryness, and fully ground with a ball mill at a rotational speed of 500 r/min for 3 hours to obtain solid powder;

In step 3, the solid powder obtained in step 2 is heated for 4 hours under an argon atmosphere and a temperature of 1000 ° C, cooled to room temperature, and ground in a ball mill for 40 minutes at a rotational speed of 500 r/min to obtain the desired catalyst. The transition metals contained in the catalyst are anchored to defect sites on the surface of the support in the form of single atoms.

Example 10

Step 1, add 5g/L silver nitrate acetone solution into fumed silica (inorganic silicon-based carrier), wherein the mass ratio of transition metal to carrier is 1:20, and the obtained solution is uniformly dispersed by ultrasound for 30min under the condition of 100kHz, and then Stir the mixed solution at 100r/min for 12h;

Step 2, the mixed solution obtained in step 1 is heated to the boiling point of acetone, volatilized at high temperature, evaporated to dryness, and fully ground with a ball mill for 0.5 hours at a rotational speed of 50 r/min to obtain solid powder;

In step 3, the solid powder obtained in step 2 is heated for 2 hours under an argon atmosphere and a temperature of 180° C., cooled to room temperature, and ground in a ball mill for 20 minutes at a rotational speed of 50 r/min to obtain the desired catalyst. The transition metals contained in the catalyst are anchored to defect sites on the surface of the support in the form of single atoms.

Example 11

Antibacterial experimental tests were carried out on a series of single-atom catalysts prepared in Preparation Examples 1-10:

Step 1, prepare freshly cultivated bacteria (Staphylococcus aureus, Escherichia coli, Salmonella) for 18-24h, wash the bacterial lawn with 5mL PBS solution (0.03mol/L) to configure a bacterial suspension, and dilute it with PBS to the desired concentration ( Drop 100 μL on the control sample, and the number of recovered bacteria is 1×10 ⁴ -9×10 ⁴ cfu/chip);

Step 2, respectively take by weighing a certain amount of catalyst and control sample and disperse in PBS to configure sample solution (concentrations are respectively 0, 1000ppm, 2000ppm, 3000ppm, 4000ppm, 5000ppm), put into a 250ml conical flask;

Step 3, fix the conical flask on the shaking shaker, shake at 300r/min for 1h;

Step 4: Take 0.5mL sample solution at 0 time and after shaking for 1h respectively, or make appropriate dilution with PBS, inoculate the plate by agar pouring method, and incubate it in a 36-37 degree incubator for 18-24 hours. Colony count.

The test was repeated 3 times, and the bacteriostatic rate was calculated according to the formula:

X=(A-B)/A×100%

where:

X——antibacterial rate, %;

A——the average number of colonies before the test sample is shaken;

B——The average number of colonies after the test sample was shaken.

As shown in Figures 1-3, under the condition of 2000ppm, the removal rate of each single-atom catalyst to Staphylococcus aureus, Escherichia coli, and Salmonella can reach more than 99%. As shown in Figure 4, the single-atom catalysts prepared by different series of inorganic carriers all showed an antibacterial rate of >99%, which once again proved the excellent antibacterial performance of a series of inorganic antibacterial and anti-mildew single-atom catalysts prepared in this patent.

Example 12

A series of single-atom catalysts prepared in Preparation Examples 1 to 10 were tested for antibacterial experiments in practical application scenarios:

Step 1. Select the actual living fish pond water, river water, landscape lake and other scenarios rich in bacteria for testing. Take 1L of raw water, and after 30 minutes of precipitation, take 100mL of it and add 100mL of purified water to dilute it. A total of 200mL is used as the bacteria-containing solution. Raw water, the number of colonies is 1×10 ³ -5×10 ³ cfu/piece.

Step 2, take by weighing a certain amount of catalyst and reference sample respectively and be dispersed in above-mentioned raw water (concentrations are respectively 0, 1000ppm, 2000ppm, 3000ppm, 4000ppm, 5000ppm), put into a 250ml conical flask;

Step 3, fix the conical flask on the shaking shaker, shake at 300r/min for 1h;

Step 4: Take 1 mL of sample solution at 0 time and after shaking for 1 hour, inoculate a plate by the agar pouring method, and culture for 18-24 hours in a 36-37 degree incubator to count the colonies.

The test was repeated 3 times, and the bacteriostatic rate was calculated according to the formula:

X=(A-B)/A×100%

where:

X——antibacterial rate, %;

A——the average number of colonies before the test sample is shaken;

B——The average number of colonies after the test sample was shaken.

As shown in Figure 5, the practical application scenarios of different series of inorganic-supported single-atom catalysts for broad-spectrum antibacterial all showed >99% antibacterial rate.

Example 13

A series of single-atom catalysts prepared in Preparation Examples 1 to 10 were compared with traditional antibacterial materials, and the traditional materials were selected as potassium hydrogen persulfate (DuPont Victor) and benzalkonium chloride (Zunuo, New Zealand) as a comparison. , and the antibacterial performance of the catalyst was monitored in real time, and the experimental method was consistent with Example 12. As shown in Figure 6, under the same conditions, the three products all showed an antibacterial rate of about 80% after 1 h. However, DuPont Wei can gradually lose its effect after 12h; New Zealand Zuno showed 99% antibacterial rate at 12h and lasted for 5 days, and then gradually lost its effect; All showed an antibacterial rate of 99%, and after 30 days of continuous testing, they could still maintain an antibacterial rate of >99% and could continue to function.

Example 14

A series of single-atom catalysts prepared in Preparation Examples 1-10 were recovered, and the performance of the catalysts was tested cyclically.

Step 1, test according to the experimental method described in Example 12;

Step 2, the catalyst was recovered by centrifugation, washed three times with water and ethanol, dried in a vacuum at 80 degrees, and then tested again according to Example 12;

In step 3, the operation described in step 2 is repeated more than 100 times.

Each single-atom catalyst showed a removal rate of >99% for a variety of bacteria, and the antibacterial performance was not attenuated after repeated recycling for more than 100 times.

Claims (9)

1. A series of inorganic antibacterial and mildew-proof single-atom catalysts, characterized in that, the single-atom catalyst is composed of a carrier and a transition metal, and the carrier is an inorganic calcium-based carrier, an inorganic silicon-based carrier, an inorganic aluminum-based carrier and an inorganic titanium carrier Any one of the base supports; the transition metal is selected from one or more of the first transition metal to the second transition metal; the transition metal is anchored at the defect site on the surface of the support in the form of a single atom. 2 . The antibacterial and mildew-proof single-atom catalyst according to claim 1 , wherein the inorganic calcium-based carrier is any one of calcium carbonate, calcium phosphate, calcium silicate, and hydroxyapatite. 3 . 3 . The antibacterial and mildew-proof single-atom catalyst according to claim 1 , wherein the inorganic silicon-based carrier is any one of diatomite, kaolin, nano-silica, and fumed silica. 4 . 4 . The antibacterial and mildew-proof single-atom catalyst according to claim 1 , wherein the inorganic aluminum-based carrier is any one of alumina and kaolin. 5 . 5 . The antibacterial and mildew-proof single-atom catalyst according to claim 1 , wherein the inorganic titanium-based carrier is any one of titanium dioxide, nano-titanium dioxide, and Degussa P25. 6 . 6. according to the arbitrary described antibacterial and mildew proof single atom catalyst of claim 1-5, it is characterized in that, described transition metal is selected from one or more in Fe, Co, Ni, Cu, Ag, Mn and Zn , the mass ratio of the transition metal and the carrier contained in the catalyst is 1:20-1:200. 7. the preparation method of the arbitrary described single-atom catalyst of claim 1-6, is characterized in that, described comprises the following steps: 1) ultrasonically, stirring and mixing the transition metal salt solution and the carrier; 2) removing the solvent of the product obtained in step 1), and grinding to obtain a solid powder; 3) The solid powder obtained in step 2) is subjected to heat treatment, cooled and then ground to obtain the desired catalyst. 8 . The antibacterial and mildew-proof single-atom catalyst according to claim 7 , wherein the concentration of the metal salt solution in step 1) is 5-200 g/L, and the metal salt is a chloride salt, a nitrate salt, or a sulfate salt. 9 . In any one of the above, the solvent of the solution is any one of water, an organic solution, and a water-organic mixed solvent, and the stirring time is 12-48 h. 9 . The antibacterial and mildew-proof single-atom catalyst according to claim 7 , wherein the heat treatment in step 3) is heating at a temperature of 50 to 1000° C. for 2 to 4 hours in an air or argon atmosphere, and the grinding time is 20 minutes. 10 . ~40min.

Images