Silver-copper synergistically modified titanium-zinc-based difunctional composite material and preparation method thereof

Abstract

The preparation method is characterized by comprising the following steps: putting TiO2, a zinc base, a copper source and a silver source into a spheroidal graphite tank, taking water as a dispersing agent, adding a proper amount of organic PVP (Polyvinyl Pyrrolidone), carrying out ball milling, and drying to obtain a silver-copper series titanium-zinc-based antibacterial agent. PVP not only can inhibit phase transformation from anatase to rutile, but also can obtain a material which is relatively good in dispersity and has double functions of degradation and broad-spectrum antibacterial characteristics. The method breaks through the limitation of a traditional multi-step preparation process, has the outstanding advantages of being short in technological process, low in energy consumption, suitable for continuous production and the like, and provides a new thought for implementing development of novel antibacterial materials.

Description

Technical Field

[0001] The present invention relates to the field of antibacterial and photocatalytic materials, and in particular to a composite material modified by the synergistic action of silver and copper bimetallics and having dual functions (antibacterial and photocatalytic) and a preparation method thereof. Background Art

[0002] In recent years, with the influence of factors such as global warming and air pollution, the incidence of respiratory and heart diseases has continued to rise. The development of new antibacterial and purification materials to create a clean and safe living environment for humans is of great significance to improving the human living environment and protecting people's physical health. As a new type of functional material, "antibacterial" materials have developed rapidly in the 1990s. It is a general term for sterilization, disinfection, sterilization, sterilization, purification, antiseptic, mildew prevention and antibacterial. Photocatalytic antibacterial materials have the functions of effective antibacterial and photocatalytic degradation of organic pollutants, and the ability to inhibit and kill microorganisms. Semiconductor photocatalytic technology uses clean and easily available solar energy as energy and is considered to be a sterilization method with great application prospects. It is fast, effective, and not easy to produce bacterial resistance.

[0003] At present, it is known that the composite materials of TiO2 and ZnO have antibacterial properties. The current preparation method of the composite materials of nano-TiO2 and ZnO mainly adopts co-precipitation and then calcination operation, which is a step-by-step preparation method, such as:

[0004] Chinese patent application No. 201210456102.5 discloses a method for preparing zinc oxide / titanium dioxide nanocomposites, which uses a coprecipitation-supercritical fluid drying method to prepare ZnO / TiO2 nanocomposites. Although this method has a high output ratio, the reaction conditions are harsh and the reaction needs to be carried out in a supercritical reactor at high temperature and high pressure, which to a certain extent limits the application of this method.

[0005] CN 118020790 A dissolves zinc acetate dihydrate and nano-titanium dioxide in deionized water, stirs to obtain a mixed solution, dries the mixed solution to a constant weight, and collects a sample; calcines the collected sample, and then naturally cools it to room temperature to obtain a calcined powder sample; the calcined powder sample is mixed with stearic acid, carboxymethyl cellulose, and cyclohexane, and ball-milled to obtain a nano-titanium dioxide-zinc oxide composite antibacterial and antialgae agent.

[0006] The above methods have the problems of complicated operation methods and high production costs.

[0007] The applicant found that although the composite material of TiO2 and ZnO prepared by ball milling has the dual functional characteristics of heterojunction, can degrade organic matter, and has antibacterial effect, the antibacterial effect of the composite material of TiO2 and ZnO is limited. Therefore, it is hoped that its antibacterial effect can be further improved. Summary of the Invention

[0008] In response to the above technical problems, the first objective of the present invention is to provide a method for preparing a silver-copper synergistically modified bifunctional composite material. The second objective is to provide a silver-copper synergistically modified bifunctional composite material. This method has a simple preparation process, and the resulting silver-copper synergistically modified bifunctional composite material has excellent antibacterial efficacy.

[0009] In order to achieve the above-mentioned first purpose, the present invention provides a preparation method of a silver-copper synergistically modified bifunctional composite material, which is characterized by: TiO2, a zinc base, a copper source, and a silver source are placed in a spherical ink tank, water is used as a dispersant, a ball milling medium is added, and ball milling is performed. After the ball milling is completed, the process is filtered and dried to obtain a silver-copper titanium-zinc-based antibacterial agent.

[0010] In the above scheme, TiO2 is at least one of anatase, rutile, brookite or mixed crystal types.

[0011] In the above scheme: the zinc group is one of ZnO, ZnCl2, Zn(OH)2, ZnCO3, basic zinc carbonate, and Zn(NO3)2.

[0012] In the above scheme: the silver source is one of AgNO3, AgCl, Ag2O, and nanosilver.

[0013] In the above scheme: the copper source is one of CuO, CuSO4, copper acetate, copper chloride, and copper nitrate.

[0014] In the above scheme: the ball milling medium is zirconia beads, the ball-to-material ratio is 10-20:1, and the particle size gradient is configured according to the volume ratio of large beads Φ5-10mm, medium beads Φ3-5mm, and small beads Φ1-3mm, 1-3:2-5:3-8.

[0015] In the above scheme: the ball milling time is 0.5-24h, and the ball milling speed is 200-1000r / min.

[0016] In the above scheme, the zinc base, silver source and copper source account for 5-90%.

[0017] In the above scheme: according to the mass ratio, the mass ratio of TiO2, zinc base, silver source and copper source is 5:4-1:1-2:1-2.

[0018] The second object of the present invention is achieved as follows: the silver-copper synergistically modified bifunctional composite material prepared by the preparation method of the silver-copper synergistically modified bifunctional composite material has a particle size of 20 nanometers to 10 microns.

[0019] The ball milling method grinds particles continuously for a long time, and the particles are crushed under strong collisions, and the shape and size of the particles change. High-energy ball milling is a solid powder processing technology that can synthesize various equilibrium and non-equilibrium alloy phases starting from elemental powders, and at the same time reduce the crystallite size of the resulting product relative to the starting components. If two or more powders are put into a ball mill equipped with a ball milling jar for ball milling, the powder particles undergo a cycle of rolling, pressing, crushing, and pressing again, and finally a multiphase structure with uniform organization and composition distribution is obtained. Compared with traditional wet chemical methods, this technology has the following advantages: (1) It avoids the use of solvents and conforms to the concept of green chemistry; (2) The metal components are dispersed at the atomic level through mechanical alloying; (3) The process parameters (speed, time, ball-to-material ratio, etc.) can accurately control the microstructure of the material. At the same time, the high-energy ball milling method has also attracted widespread attention due to its low price, environmental friendliness, high controllability and high efficiency, and this method is also suitable for large-scale industrial production.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] (1) Metal ions (Ag 0 、 ) in situ doping to broaden the photoresponse range of ZnO to the visible light region.

[0022] (2) Ball milling-induced lattice distortion forms oxygen vacancy defects, constructing a ZnO-TiO2 type II heterojunction, promoting the effective separation of photogenerated electron-hole pairs, and silver-copper nanoclusters act as electron traps to suppress carrier recombination.

[0023] (3) The surface-enriched silver nanoclusters and copper ions provide a dual antibacterial effect of contact sterilization and ion sustained release, significantly improving the antibacterial performance.

[0024] (4) Silver-copper nanoclusters kill bacteria by contact (Ag 0 Cell membrane penetration effect) and ion release (Cu 2+ The sustained release of Ag 0 ) and photocatalytic production of ROS (·OH, O2 - ) of synergistic sterilization.

[0025] (5) Through the mechanochemical effect of high-energy ball milling, the raw material nano-sizing, heterojunction formation and defect engineering modification are completed simultaneously. The process is simple and the cost is low. It can also achieve material nano-sizing, heterojunction construction and metal loading in one step.

[0026] (6) The high-energy ball milling method is used to achieve solid-state mechanical alloying, which not only avoids the use of solvents but also achieves nano-sizing and uniform dispersion of raw materials. The process is simple, low-cost and suitable for large-scale industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is the SEM image of Example 1.

[0028] Figure 2 This is the SEM image of the mixture without ball milling.

[0029] Figure 3 This is the SEM image of ball milling at 200r / min for 20min.

[0030] Figure 4 This is a photodegradation experimental device. DETAILED DESCRIPTION

[0031] The present invention will be further described below by way of examples and in conjunction with the accompanying drawings:

[0032] Example 1

[0033] Anatase TiO2, ZnO, CuO, and AgNO3 were mixed in a ball mill at a mass ratio of 5:4:1:2. Water was used as a dispersant. Zirconia beads were added at a ball-to-material ratio of 15:1. The volume ratio of large beads: medium beads: small beads was 1:2:3. The large beads were Φ5-10 mm, the medium beads were Φ3-5 mm, and the small beads were Φ1-3 mm. The ball mill speed was 360 r / min, and the ball milling time was 8 hours. The powder was then filtered and dried to obtain a silver-copper titanium-zinc-based antibacterial agent. Antibacterial tests were conducted on Sa and Ec using the oscillation method. After one hour of dark reaction oscillation, the antibacterial rates of Sa and Ec were 90% and 95% respectively. The inhibition zone size of Sa was 2 mm and that of Ec was 3.5 mm. Under irradiation with a 300W mercury lamp, the photodegradation rate was 95.2% and the photodegradation time was 25 minutes.

[0034] Figure 1 This is the SEM image of Example 1. Figure 1 (a)- Figure 1 In (c), we can clearly observe that the composite product exists in the form of irregular spheres, and through Figure 1 (d)- Figure 1 (f) It can be seen that the ZnO irregular columns are completely covered by TiO2, Ag, and Cu, and a heterojunction is formed between the four different materials.

[0035] Figure 2 The SEM images of the materials obtained by direct mixing according to the ratio of Example 1 without ball milling are shown in Figure 1. The composite product exists in irregular spherical shape. Figure 2 (b) and Figure 2 In (c), ZnO blocks can be clearly observed on the TiO2 surface. Figure 2 (d)- Figure 2 (f) It is not completely coated by TiO2, Ag, and Cu, and the nanosilver is unevenly dispersed through mapping test, so no heterojunction is formed between the composite products that have not been ball-milled.

[0036] Figure 3 The rest is the same as Example 1, except that the SEM image of the ball milling at 200 r / min for 20 min is shown in Figure 3 In (a), it can be observed that the size of the composite product is between 1 and 10 μm and the shape is blocky. Figure 3 (b), 3(c) and Figure 3 As can be seen in (c), there is no nano-Ag on the ZnO surface, but Figure 3 (f) It can be seen that there is a large amount of Cu on the surface of ZnO. Therefore, we believe that TiO2 and Ag are completely covered, and no heterojunction is completely formed among TiO2, Ag, Cu, and ZnO.

[0037] The photocatalytic degradation experiment used methyl orange to simulate organic water pollutants (the following examples were carried out using the same method). The specific operation is as follows:

[0038] (1) Add 0.1 g of the prepared titanium zinc-based antibacterial agent powder to 10 mg / L methyl orange solution (100 mL).

[0039] (2) Place the beaker in a dark environment (ignore the influence of natural light) and stir for 30 minutes before taking a sample.

[0040] (3) Turn on the photocatalytic device and take samples every 0.5 h during stirring until the photocatalytic reaction is completed. The experimental device is homemade, such as Figure 4 .

[0041] In the concentration range of 0 to 20 mg / L, the concentration at the absorbance can be calculated using the standard curve equation y = 0.086x - 0.0385, and then the degradation rate can be calculated using the following degradation rate formula:

[0042]

[0043] Where: η represents the degradation rate of methyl orange solution (%); C0 represents the initial concentration of methyl orange (mg / L); C tIt represents the concentration of methyl orange solution at time t calculated based on the standard curve (mg / L).

[0044] Example 2

[0045] Rutile TiO2, ZnCO3, copper chloride, and AgCl were prepared in a mass ratio of 5:1:2:2, with water as the dispersant. Zirconia beads were added at a ball-to-material ratio of 15:1, and the volume ratio of large beads: medium beads: small beads was 1:2:3. The milling speed was 400 r / min, and the milling time was 6 hours. The titanium-zinc-based antibacterial agent powder was then filtered and dried to form a heterojunction between the four different materials. Antibacterial tests were conducted on Sa and Ec using the oscillation method. After two hours of dark reaction oscillation, the antibacterial rates of Sa and Ec were 96% and 92% respectively. The inhibition zone size of Sa was 2 mm, and the inhibition zone size of Ec was 3.5 mm. Under irradiation with a 300W mercury lamp, the photodegradation rate was 95.5% and the photodegradation time was 30 minutes.

[0046] Example 3

[0047] Brookite-type TiO2, Zn(OH)2, CuNO3, and Ag2O were prepared in a mass ratio of 5:4:2:1. Water was used as a dispersant, and zirconium oxide beads were added at a ball-to-material ratio of 15:1. The ratio of large beads: medium beads: small beads was 1:2:3. The milling speed was 1000 r / min, and the milling time was 0.5 h. The titanium-zinc-based antibacterial agent powder was then filtered and dried. A heterojunction was formed between the four different materials. Antibacterial tests were conducted on Sa and Ec using the oscillation method. After two hours of dark reaction oscillation, the antibacterial rates of Sa and Ec were 94% and 93% respectively. The inhibition zone size of Sa was 2.5 mm, and the inhibition zone size of Ec was 3.5 mm. Under irradiation with a 300W mercury lamp, the photodegradation rate was 94.7% and the photodegradation time was 30 min.

[0048] Example 4

[0049] Brookite-type TiO2, ZnCl2, CuSO4, and Ag2O were prepared in a mass ratio of 5:4:2:2. Water was used as a dispersant. Zirconia beads were added at a ball-to-material ratio of 15:1, with a ratio of large beads: medium beads: small beads of 1:2:3. The milling speed was 400 r / min for 6 hours. The titanium-zinc-based antimicrobial powder was then filtered and dried to form a heterojunction between the four different materials. Antibacterial tests were conducted on Sa and Ec using the oscillation method. After two hours of dark reaction oscillation, the antibacterial rates of Sa and Ec were 94.3% and 93.5% respectively. The inhibition zone size of Sa was 2 mm, and that of Ec was 3.5 mm. Under irradiation with a 300W mercury lamp, the photodegradation rate was 95.2% and the photodegradation time was 30 minutes.

[0050] Example 5

[0051] Anatase TiO2 and ZnO were mixed in a 5:4 mass ratio in a three-dimensional planetary ball mill. Water was used as a dispersant, and zirconia beads were added at a ball-to-material ratio of 15:1. The volume ratio of large beads: medium beads: small beads (large, medium, and small particle sizes are: large beads Φ5-10mm, medium beads Φ3-5mm, and small beads Φ1-3mm) was 1:3:6. The ball milling speed was 300r / min, and the ball milling time was 8h. The titanium-zinc-based antibacterial agent powder was then filtered and dried to obtain a typical morphological feature consistent with a heterojunction structure. Scanning electron microscopy (SEM) revealed that the powder had a typical morphological feature consistent with a heterojunction structure. Antibacterial tests were conducted on Sa and Ec using the oscillation method. After two hours of dark reaction oscillation, the antibacterial rate of Sa was 60%, and the antibacterial rate of Ec was 74%. The inhibition zone size was 4mm. Under irradiation with a 300W mercury lamp, the photodegradation rate was 96.7% and the photodegradation time was 90min.

[0052] The present invention is not limited to the above embodiments. The TiO2 crystal form includes anatase, rutile, brookite, or a mixed crystal form. The zinc-based material includes ZnO, ZnCl2, Zn(OH)2, ZnCO3, basic zinc carbonate, Zn(NO3)2, etc. The silver source includes AgNO3, AgCl, Ag2O, nanosilver, etc. The copper source includes CuO, CuSO4, copper acetate, copper chloride, copper nitrate, etc. The above-mentioned TiO2, zinc-based material, silver source, and copper source can also be combined in any manner. The rotation speed is controlled between 200-1000 r / min and the ball milling time is 0.5-24h. When the ball milling speed is high, the ball milling time is short enough to form a heterojunction. During ball milling, the mixture and the grinding medium can be added in any ratio of (10-20):1. Those skilled in the art will understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and purpose of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A method for preparing a silver-copper synergistically modified bifunctional composite material, characterized by: TiO2, zinc base, copper source and silver source are placed in a ball ink tank, water is used as a dispersant, ball milling medium is added, and ball milling is performed. After the ball milling is completed, the ball milling is filtered and dried to obtain a silver-copper titanium-zinc-based antibacterial agent.

2. The method for preparing the silver-copper synergistically modified bifunctional composite material according to claim 1, characterized in that: TiO2 is at least one of anatase, rutile, brookite or mixed crystal types.

3. The method for preparing the silver-copper synergistically modified bifunctional composite material according to claim 2, characterized in that: The zinc group is one of ZnO, ZnCl2, Zn(OH)2, ZnCO3, basic zinc carbonate, and Zn(NO3)2.

4. The method for preparing the silver-copper synergistically modified bifunctional composite material according to claim 3, characterized in that: The silver source is one of AgNO3, AgCl, Ag2O and nanosilver.

5. The method for preparing the silver-copper synergistically modified bifunctional composite material according to claim 4, characterized in that: The copper source is one of CuO, CuSO4, copper acetate, copper chloride and copper nitrate.

6. The method for preparing the silver-copper synergistically modified bifunctional composite material according to any one of claims 1 to 5, characterized in that: The ball milling medium is high-density zirconia beads, which adopt a three-level particle size gradient configuration with a ball-to-material ratio of 10-20:

1. The particle size gradient configuration is based on a volume ratio combination of large beads Φ5-10mm, medium beads Φ3-5mm, and small beads Φ1-3mm, with a volume ratio of 1-3:2-5:3-8.

7. The method for preparing the silver-copper synergistically modified bifunctional composite material according to claim 6, characterized in that: The ball milling time is 0.5-24h, and the ball milling speed is 200-1000r / min.

8. The method for preparing the silver-copper synergistically modified bifunctional composite material according to claim 7, characterized in that: Zinc-based, silver-based and copper-based sources account for 5-90%.

9. The method for preparing the silver-copper synergistically modified bifunctional composite material according to claim 8, characterized in that: According to the mass ratio, the mass ratio of TiO2, zinc base, silver source and copper source is 5:4-1:1-2:1-2.

10. A silver-copper synergistically modified titanium-zinc-based bifunctional composite material prepared by the preparation method of the silver-copper synergistically modified bifunctional composite material according to any one of claims 1 to 9.

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