A piezoelectric photocatalytic antibacterial material and its preparation method and application

Abstract

The present invention belongs to the field of antibacterial materials, and in particular relates to a piezoelectric photocatalytic antibacterial material and its preparation method and application. The method comprises: x Zn 1‑x A manganese source and a zinc source are separately mixed with an alkaline sodium compound solution and bentonite, and then subjected to low-speed ball milling and autothermal ball milling, respectively, to obtain the piezoelectric photocatalytic antibacterial material; wherein: 0<x<1. The piezoelectric photocatalytic antibacterial material prepared by the present invention has strong piezoelectricity and, while having high adsorption capacity, its positive charge interferes with bacterial activity, thereby achieving effective antibacterial and odor-removing effects. The preparation process is characterized by simple operation, low energy consumption, economical practicality, and a short production cycle.

Description

Technical Field

[0001] The present invention belongs to the field of antibacterial materials, and in particular relates to a piezoelectric photocatalytic antibacterial material and a preparation method and application thereof. Background Art

[0002] As an advanced sterilization method, photocatalytic technology has been used as early as 2003. Under ultraviolet light, photocatalysts have a high inactivation rate for SRAS viruses. In Japan, photocatalysts are sprayed on the floors or walls of operating rooms and combined with ultraviolet rays for catalytic sterilization. The sterilization effect is far superior to traditional sterilization and disinfection technologies. In recent years, there have been frequent reports on the use of photocatalytic technology to eliminate and prevent pathogens such as MERS virus, Ebola virus, and H1N1. On April 28, 2020, the inner surface of the antibacterial channel of Hong Kong International Airport was provided with a photocatalytic antibacterial coating. The use of photocatalytic technology can achieve remote elimination of bacteria and viruses on the human body and clothing. When the photocatalyst is irradiated by light, it can generate electron-hole pairs, which react with water and oxygen in the air to generate reactive oxygen free radicals (ROS), such as hydroxyl radicals (·OH), superoxide radicals (·O 2- ) and singlet oxygen ( 1 O2), hydrogen peroxide (H2O2) and other active species. These active species have strong oxidizing properties and can react with organic matter in bacteria and the toxins secreted by them, destroying the bacteria's reproduction and regeneration ability, thereby reducing the vitality of the bacteria. At the same time, these self-active species can conquer bacteria and outer bacteria, penetrate the bacterial membrane of bacteria and destroy the bacterial membrane structure, thereby completely killing the bacteria. What is more noteworthy is that after the bacteria and viruses are inactivated and killed, photocatalysis can efficiently decompose and remove the remaining corpses. In recent years, in order to develop high-efficiency, long-lasting and low-toxic antibacterial agents, some new bactericidal and disinfectant materials have received increasing attention.

[0003] Among them, piezoelectric semiconductor catalysts, due to their unique performance advantages, can play an important role in sterilization and disinfection when combined with photocatalysis. Piezoelectric catalysts exhibit ultra-high inactivation properties against bacteria by utilizing non-centrosymmetric promotion of ROS production in redox reactions under mechanical forces (such as ultrasonic vibration).

[0004] However, existing piezoelectric materials generally exhibit different charges when different surfaces are subjected to force. For example, some piezoelectric ceramics produce charges on their surfaces, one positive and one negative, when subjected to pressure. These charges reverse polarity when subjected to tension. At a microscopic level, powdered piezoelectric materials exhibit a correlation with the surface on which they are subjected. However, in actual use, there's no way to guarantee that the surface on which the force is applied will conform to expectations, resulting in very limited practical applications.

[0005] Moreover, after the piezoelectric semiconductor material is loaded by some conventional carriers, its actual photocatalytic ability is significantly inhibited, resulting in poor actual use effects. Summary of the Invention

[0006] In order to solve the problems that existing piezoelectric semiconductor materials have good antibacterial application prospects but are subject to great limitations in actual use and their piezoelectric properties are difficult to exert, the present invention provides a piezoelectric photocatalytic antibacterial material, as well as a preparation method and application of the antibacterial material.

[0007] The objects of the present invention are:

[0008] 1. A stable piezoelectric photocatalytic antibacterial material can be effectively prepared;

[0009] Second, the prepared piezoelectric photocatalytic antibacterial material has good photocatalytic antibacterial effect;

[0010] 3. The piezoelectric properties of the prepared piezoelectric photocatalytic antibacterial material can be effectively applied.

[0011] To achieve the above objectives, the present invention adopts the following technical solutions.

[0012] A method for preparing a piezoelectric photocatalytic antibacterial material,

[0013] The method comprises:

[0014] According to the stoichiometric formula Mn x Zn 1-x O respectively taking a manganese source and a zinc source, mixing them with an alkaline sodium compound solution and bentonite, and sequentially performing low-speed ball milling and autothermal ball milling to obtain the piezoelectric photocatalytic antibacterial material;

[0015] Among them: 0<x<1.

[0016] Preferably, the manganese source is a soluble divalent manganese compound;

[0017] The zinc source is a soluble zinc salt.

[0018] Preferably, the alkaline sodium compound solution is a sodium bicarbonate solution;

[0019] The pH value of the sodium bicarbonate solution is adjusted to 8.5-9.5.

[0020] Preferably, the sodium bicarbonate content in the alkaline sodium compound solution is 1.2 to 1.5 mmol / g bentonite.

[0021] Preferably, the total molar amount of manganese and zinc contained in the manganese source and the zinc source is 0.5 to 0.8 mmol / g bentonite.

[0022] Preferably, the low-speed ball milling process controls the ball milling speed to be 150-250 rpm and the ball milling time to be 25-35 min.

[0023] Preferably, the ball milling speed is controlled to be 350-450 rpm and the ball milling time is 45-60 min during the autothermal ball milling process.

[0024] A piezoelectric photocatalytic antibacterial material.

[0025] An application of a piezoelectric photocatalytic antibacterial material. The piezoelectric photocatalytic antibacterial material is used for making cat litter or is directly mixed with cat litter for use.

[0026] In the technical solution of the present invention, the core is to prepare a mixed structure of Mn(Ac)2·4H2O and Zn(Ac2·2H2O. x Zn 1-x O(MZO) system quantum dots, on the one hand, the MnO formed in the system x Most of them are nano-sized particles. Bentonite has a great influence on the MnO x The adsorption of MnO is consistent with the Langmuir adsorption model. The thermodynamic parameters show that the adsorption process is an exothermic and spontaneous process with high binding strength. x The composition is conducive to ZnO x The loading of MZO can improve the problem of unstable thermodynamic properties and reduce the obvious deformation, dendrites, passivation and other phenomena of MZO. At the same time, after characterization, the surface and interlayer of MZO mixed oxide contain more crystal water and adsorbed water, and the surface contains rich hydroxyl groups, which provide more adsorption sites and improve the absorption of ZnO. x In addition, attention should be paid to the amount of reactants used. If the initial concentration of the reactants is too high, the nucleation rate of the product will be greater than the growth rate, and the grain collision rate will increase, thus leading to particle agglomeration. On the other hand, ZnO x While maintaining the low permeability coefficient of bentonite, the expansion and impermeability of bentonite are improved. According to the research of those skilled in the art, it is found that ZnO x Promotes multi-layer adsorption of bentonite and improves the adsorption of bentonite to MnO x saturated adsorption capacity.

[0027] Another core of the present invention is the sodium modification of bentonite. Non-sodium ions in bentonite are replaced by sodium ions. Bentonite swells in the solution and undergoes interlayer peeling under the action of mechanical force, dissolving non-sodium ions to obtain sodium bentonite. Bentonite has great economic value in application, especially sodium bentonite. There are many problems in the sodium modification method, the reaction is complex and the effect is difficult to control. Generally speaking, Ca 2+ Bentonite with extremely high content is suspended in the form of stratified crystals, and the sodium reaction only occurs on the surface.2+ Hydration occurs in solution, forming a layer that blocks Ca 2+ The membrane of ion diffusion has affected the exchange of cations. Therefore, the conditions in the sodiumization process should be strictly controlled to ensure that complete in-situ sodiumization is achieved. The most important thing in the sodiumization conditions is that different sodiumizing agents have a greater impact on the sodiumization quality. Experimental findings show that the bentonite interlayer spacing has reduced by approximately 0.247nm, and every gram of bentonite cation exchange capacity has increased to 1.01mmol / g from 0.68mmol / g. According to the result of bentonite content and cation exchange capacity, it is found that using sodium bicarbonate as the sodiumizing agent has the best modification effect. According to the consensus of those skilled in the art, under the condition of partial alkalinity, a large amount of negative charges are produced in the solution, which is conducive to increasing the cation exchange capacity, thereby improving the expansibility of bentonite. The speed of ion motion increases along with the rising of the sodiumization temperature. Obviously, the scope of ion diffusion increases, which accelerates the sodiumization process. Simultaneously, some chemical bonds are broken, but sodiumization can not be carried out with too high a temperature. The reason is that too high a temperature causes water evaporation, which increases the bentonite viscosity, and the sodiumizing agent and bentonite cannot fully react. Similarly, in order to fully react, the present invention uses sufficient low-speed ball milling to make the sodiumization tend to saturation, and then self-heating ball milling is carried out after the solution temperature stabilizes. Otherwise, it will not only waste energy, but also destroy the ion exchange balance and reduce the sodiumization effect.

[0028] The present invention provides short-range in-situ energy to the bentonite through ball milling, increasing the interlayer spacing of the bentonite and roughening the bentonite surface. However, during the general ball milling process, MZO has difficulty entering the bentonite interlayers and achieving uniform dispersion. Moreover, the viscosity of the modified bentonite shows a trend of first increasing and then decreasing with increasing ball milling speed, and the filtration loss shows an increasing trend. Under low-speed ball milling at 180-220 rpm / min, the interlayer spacing of the bentonite is expanded. However, the sterilization rate of the material milled at low speed for 70 minutes is also low. Characterization shows that the nanoparticles have high specific surface energy and are in a thermodynamically unstable state. Continuous low-speed ball milling results in poor particle dispersibility, i.e., agglomeration. Some agglomerations are affected by van der Waals forces and electrostatic forces, while others are bonded by chemical bonds. The extrusion, friction, and collision generated by high-speed ball milling cause the bentonite to continuously deform. After characterization, it was found that the absolute value of the Zeta potential of the material was small under high-speed ball milling, and MnZnO generated quantum dots in situ. At the same time, the present invention added polyethylene glycol, a polymer electrolyte, to form a "shell" on the surface of the quantum dots, increasing the specific surface area of ​​the quantum dots, further stabilizing the dispersed quantum dots, reducing their surface energy, and reducing the occurrence of agglomeration. The quantum dots showed excellent photocatalytic activity and stability. While ensuring sufficient ball milling, the present invention achieved in-situ doping of bentonite, and MZO was evenly distributed in the bentonite. Not only that, MZO can synergistically improve the degree of sodiumization. Its charge effect and steric hindrance are greater than those of Na ions, driving Na ions to move between bentonite layers, promoting interlayer sodiumization, and at the same time enhancing the adsorption capacity of bentonite. MZO quantum dots with excellent piezoelectricity are evenly dispersed on the surface and between layers of bentonite. In the case of high adsorption capacity, its positive charge interferes with bacterial activity and can play an effective antibacterial and deodorizing role.

[0029] The bentonite with piezoelectric antibacterial properties of the present invention does not require the introduction of other antibacterial ions, organic antibacterial agents, and other materials. Instead, it relies on the inorganic piezoelectric antibacterial material to generate an internal polarization electric field under the action of external mechanical forces (vibration, water flow, etc.), drive electron / hole migration, and generate active groups on the surface. No external power source or special stimulation source is required. It is a bentonite material with piezoelectric antibacterial properties with a wide range of applications. The introduction of piezoelectric polarization can significantly enhance the photocatalytic activity of the material. The piezoelectric catalytic mechanism under mechanical stimulation (the squeezing force of the piezoelectric material caused by the expansion of the bentonite when it encounters water and the pressure of the cat stepping on the cat litter) can be summarized as follows: 1) catalyzing the generation of reactive oxygen species to kill bacteria through redox reactions; 2) generating electrical signals to affect biological activity, thereby promoting bacterial apoptosis; the ROS generated by the piezoelectric effect can also participate in the electron transfer chain of bacterial metabolism, thereby destroying the bacterial wall and denaturing bacterial proteins. The present invention not only utilizes piezoelectric catalysis coupled with photocatalysis to synergistically enhance the bactericidal and disinfecting ability of the material, exploring a new path for the future development of bactericidal materials, but also has important significance for the development of efficient and long-lasting antibacterial cat litter products. The present invention is to use Mn with metal vacancies xZn 1-x O (x = 0.1 ~ 0.5) piezoelectric antibacterial material is closely combined with modified sodium bentonite to prepare a piezoelectric antibacterial material with high efficiency and long-term stability. The high-valent Mn site on the MZO surface has strong oxidizing properties, which realizes Mn oxidation through photogenerated holes. 3+ / Mn 4+ Towards high valence Mn 4+x The redox cycle valence of the product serves as a renewable antibacterial site, and has a high-efficiency and long-lasting antibacterial effect against bacteria such as Escherichia coli and Staphylococcus aureus.

[0030] The beneficial effects of the present invention are:

[0031] 1) The piezoelectric photocatalytic antibacterial material prepared by the present invention has strong cyclic regeneration antibacterial site activity and high adsorption capacity for ammonia nitrogen compounds;

[0032] 2) The piezoelectric photocatalytic antibacterial material prepared by the present invention has strong piezoelectricity. When it has high adsorption capacity, its positive charge interferes with bacterial activity and can play an effective antibacterial and deodorizing role.

[0033] 3) The preparation process of the present invention has the characteristics of simple operation, low energy consumption, economy and practicality, and short production cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a scanning electron microscope image of the piezoelectric photocatalytic antibacterial material obtained in Example 1 of the present invention.

[0035] Figure 2 This is a comparison chart of the antibacterial test of the piezoelectric photocatalytic antibacterial material obtained in Example 1 of the present invention. DETAILED DESCRIPTION

[0036] The present invention is further described in detail below with reference to specific embodiments and the accompanying drawings. Those skilled in the art will be able to implement the present invention based on these descriptions. Furthermore, the embodiments of the present invention described below are generally only a portion of the embodiments of the present invention, rather than all of the embodiments. Therefore, all other embodiments derived by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

[0037] Unless otherwise specified, the raw materials used in the examples of the present invention are all commercially available or available to those skilled in the art; unless otherwise specified, the methods used in the examples of the present invention are all methods known to those skilled in the art.

[0038] Example 1

[0039] A piezoelectric photocatalytic antibacterial material is prepared by the following method:

[0040] According to the stoichiometric formula Mn 0.5 Zn 0.5 Manganese acetate and zinc acetate were taken separately, with a total of 60 mmol of manganese acetate and zinc acetate weighed. Subsequently, 0.135 mol of sodium bicarbonate was weighed and dissolved in deionized water to prepare a 0.5 mol / L sodium bicarbonate solution. The pH value was adjusted to 9.0 with sodium hydroxide. Manganese acetate and zinc acetate were added to the sodium bicarbonate solution, and 100 g of bentonite was added. An equal volume of polyethylene glycol was added as a medium, and the mixture was subjected to low-speed ball milling at 200 rpm for 30 min and autothermal ball milling at 400 rpm for 50 min to obtain the piezoelectric photocatalytic antibacterial material.

[0041] The obtained piezoelectric photocatalytic antibacterial material was characterized by SEM. Figure 1 As shown. Figure 1 It can be clearly seen that the surface of the piezoelectric photocatalytic antibacterial material prepared by the present invention is densely covered with nano-quantum dot structures, indicating that the MZO system is effectively deposited.

[0042] In addition, 40 mL (pH = 7) of a 100 mg / L methylene blue solution was added with 10 mg of the material obtained in this example, stirred for 24 hours, and then allowed to stand. The concentration of methylene blue in the filtrate was measured by spectrophotometry. The characterization results showed that the remaining methylene blue concentration in the filtrate was 65.3 mg / L, indicating that the piezoelectric photocatalytic antibacterial material of the present invention exhibited good adsorption performance. In addition, antibacterial performance tests were conducted, including the following:

[0043] Darkroom condition test, photocatalytic test and photocatalytic swelling test.

[0044] Darkroom test: In a darkroom, take 100 μL of a 10 7 A suspension of Staphylococcus aureus (CFU / mL) was evenly spread on an agar plate. The piezoelectric photocatalytic antibacterial material was added to the experimental group at a ratio of 0.5 mg / mL. A control group without the piezoelectric photocatalytic antibacterial material was used. After incubation overnight at 37°C, the plates were removed, the colony counts were observed, and the sterilization rate was calculated.

[0045] Sterilization rate = [1-(number of colonies in the experimental group / number of colonies in the blank control group)] × 100%.

[0046] Photocatalytic test: Under the condition of incandescent light, take 100 μL of 10 7 A suspension of Staphylococcus aureus (CFU / mL) was evenly spread on an agar plate. The piezoelectric photocatalytic antibacterial material was added to the experimental group at a ratio of 0.5 mg / mL. A control group without the piezoelectric photocatalytic antibacterial material was used. After incubation overnight at 37°C, the plates were removed, the colony counts were observed, and the sterilization rate was calculated.

[0047] Sterilization rate = [1-(number of colonies in the experimental group / number of colonies in the blank control group)] × 100%.

[0048] Photocatalytic swelling test: The prepared piezoelectric photocatalytic antibacterial material was put into excess deionized water to swell and form agglomerates. The agglomerates were ground into powder using a mortar and passed through a 200-mesh sieve to obtain a test sample. Under incandescent light, 100 μL of a 10% concentration of the sample was taken. 7 A suspension of Staphylococcus aureus (CFU / mL) was evenly spread on an agar plate. The prepared test sample was added to the experimental group at a ratio of 0.5 mg / mL. A control group without the test sample was used as a blank control. After incubation overnight at 37°C, the plates were removed, the colony counts were observed, and the sterilization rate was calculated.

[0049] Sterilization rate = [1-(number of colonies in the experimental group / number of colonies in the blank control group)] × 100%.

[0050] In the above test, the sterilization rate of the piezoelectric photocatalytic antibacterial material of the present invention under the condition of suggestion is about 89.2%, the sterilization rate of the piezoelectric photocatalytic antibacterial material of the present invention under the condition of photocatalytic test is about 97.8%, and in the photocatalytic swelling test, the test results are as follows Figure 2 As shown, Figure 2 The left picture is the colony picture of the blank control group. Figure 2 The right picture is the colony map of the experimental group, with a sterilization rate of >99%.

[0051] Example 2

[0052] A piezoelectric photocatalytic antibacterial material is prepared by the following method:

[0053] According to the stoichiometric formula Mn 0.5 Zn 0.5 Manganese acetate and zinc acetate were taken separately, and a total of 50 mmol of manganese acetate and zinc acetate were weighed. Subsequently, 0.12 mol of sodium bicarbonate was weighed and dissolved in deionized water to prepare a 0.5 mol / L sodium bicarbonate solution. The pH value was adjusted to 9.0 with sodium hydroxide. Manganese acetate and zinc acetate were added to the sodium bicarbonate solution, and 100 g of bentonite was added. An equal volume of polyethylene glycol was added as a medium, and the mixture was subjected to low-speed ball milling at 150 rpm for 35 minutes and autothermal ball milling at 350 rpm for 60 minutes to obtain the piezoelectric photocatalytic antibacterial material.

[0054] Take 40 mL (pH = 7) of a 100 mg / L methylene blue solution, add 10 mg of the material obtained in this example, stir for 24 hours and then let it stand. The concentration of methylene blue in the filtrate is determined by spectrophotometry. The characterization results show that the remaining methylene blue concentration in the filtrate is 67.3 mg / L. It can be seen that the piezoelectric photocatalytic antibacterial material of the present invention exhibits good adsorption properties.

[0055] In addition, antibacterial performance tests were conducted, including:

[0056] Darkroom condition test, photocatalytic test and photocatalytic swelling test.

[0057] Darkroom test: In a darkroom, take 100 μL of a 10 7 A suspension of Staphylococcus aureus (CFU / mL) was evenly spread on an agar plate. The piezoelectric photocatalytic antibacterial material was added to the experimental group at a ratio of 0.5 mg / mL. A control group without the piezoelectric photocatalytic antibacterial material was used. After incubation overnight at 37°C, the plates were removed, the colony counts were observed, and the sterilization rate was calculated.

[0058] Sterilization rate = [1-(number of colonies in the experimental group / number of colonies in the blank control group)] × 100%.

[0059] Photocatalytic test: Under the condition of incandescent light, take 100 μL of 10 7 A suspension of Staphylococcus aureus (CFU / mL) was evenly spread on an agar plate. The piezoelectric photocatalytic antibacterial material was added to the experimental group at a ratio of 0.5 mg / mL. A control group without the piezoelectric photocatalytic antibacterial material was used. After incubation overnight at 37°C, the plates were removed, the colony counts were observed, and the sterilization rate was calculated.

[0060] Sterilization rate = [1-(number of colonies in the experimental group / number of colonies in the blank control group)] × 100%.

[0061] Photocatalytic swelling test: The prepared piezoelectric photocatalytic antibacterial material was put into excess deionized water to swell and form agglomerates. The agglomerates were ground into powder using a mortar and passed through a 200-mesh sieve to obtain a test sample. Under incandescent light, 100 μL of a 10% concentration of the sample was taken. 7 A suspension of Staphylococcus aureus (CFU / mL) was evenly spread on an agar plate. The prepared test sample was added to the experimental group at a ratio of 0.5 mg / mL. A control group without the test sample was used as a blank control. After incubation overnight at 37°C, the plates were removed, the colony counts were observed, and the sterilization rate was calculated.

[0062] Sterilization rate = [1-(number of colonies in the experimental group / number of colonies in the blank control group)] × 100%.

[0063] In the above tests, the sterilization rate of the piezoelectric photocatalytic antibacterial material of the present invention is about 88.3% under the suggestive conditions, about 95.9% under the photocatalytic test conditions, and >99% in the photocatalytic swelling test.

[0064] Example 3

[0065] A piezoelectric photocatalytic antibacterial material is prepared by the following method:

[0066] According to the stoichiometric formula Mn 0.5 Zn 0.5 Manganese acetate and zinc acetate were taken separately, and a total of 80 mmol of manganese acetate and zinc acetate were weighed. Subsequently, 0.15 mol of sodium bicarbonate was weighed and dissolved in deionized water to prepare a 0.5 mol / L sodium bicarbonate solution. The pH value was adjusted to 9.0 with sodium hydroxide. Manganese acetate and zinc acetate were added to the sodium bicarbonate solution, and 100 g of bentonite was added. An equal volume of polyethylene glycol was added as a medium, and the mixture was subjected to low-speed ball milling at 250 rpm for 25 minutes and autothermal ball milling at 450 rpm for 45 minutes to obtain the piezoelectric photocatalytic antibacterial material.

[0067] Take 40 mL (pH = 7) of a 100 mg / L methylene blue solution, add 10 mg of the material obtained in this example, stir for 24 hours and then let it stand. The concentration of methylene blue in the filtrate is determined by spectrophotometry. The characterization results show that the remaining methylene blue concentration in the filtrate is 66.5 mg / L. It can be seen that the piezoelectric photocatalytic antibacterial material of the present invention exhibits good adsorption properties.

[0068] In addition, antibacterial performance tests were conducted, including:

[0069] Darkroom condition test, photocatalytic test and photocatalytic swelling test.

[0070] Darkroom test: In a darkroom, take 100 μL of a 10 7 A suspension of Staphylococcus aureus (CFU / mL) was evenly spread on an agar plate. The piezoelectric photocatalytic antibacterial material was added to the experimental group at a ratio of 0.5 mg / mL. A control group without the piezoelectric photocatalytic antibacterial material was used. After incubation overnight at 37°C, the plates were removed, the colony counts were observed, and the sterilization rate was calculated.

[0071] Sterilization rate = [1-(number of colonies in the experimental group / number of colonies in the blank control group)] × 100%.

[0072] Photocatalytic test: Under the condition of incandescent light, take 100 μL of 10 7 A suspension of Staphylococcus aureus (CFU / mL) was evenly spread on an agar plate. The piezoelectric photocatalytic antibacterial material was added to the experimental group at a ratio of 0.5 mg / mL. A control group without the piezoelectric photocatalytic antibacterial material was used. After incubation overnight at 37°C, the plates were removed, the colony counts were observed, and the sterilization rate was calculated.

[0073] Sterilization rate = [1-(number of colonies in the experimental group / number of colonies in the blank control group)] × 100%.

[0074] Photocatalytic swelling test: The prepared piezoelectric photocatalytic antibacterial material was put into excess deionized water to swell and form agglomerates. The agglomerates were ground into powder using a mortar and passed through a 200-mesh sieve to obtain a test sample. Under incandescent light, 100 μL of a 10% concentration of the sample was taken. 7 A suspension of Staphylococcus aureus (CFU / mL) was evenly spread on an agar plate. The prepared test sample was added to the experimental group at a ratio of 0.5 mg / mL. A control group without the test sample was used as a blank control. After incubation overnight at 37°C, the plates were removed, the colony counts were observed, and the sterilization rate was calculated.

[0075] Sterilization rate = [1-(number of colonies in the experimental group / number of colonies in the blank control group)] × 100%.

[0076] In the aforementioned tests, the piezoelectric photocatalytic antibacterial material of the present invention achieved a sterilization rate of approximately 89.6% under suggestive conditions, approximately 98.3% under photocatalytic conditions, and >99% in the photocatalytic swelling test. The characterization results of Examples 1-3 demonstrate that the piezoelectric photocatalytic antibacterial material prepared by the present invention exhibits exceptionally excellent adsorption and antibacterial properties.

[0077] Comparative Example 1

[0078] A piezoelectric photocatalytic antibacterial material is prepared by the following method:

[0079] According to the stoichiometric formula Mn 0.5 Zn 0.5 Manganese acetate and zinc acetate were taken separately, and a total of 60 mmol of manganese acetate and zinc acetate were weighed. Subsequently, 0.135 mol of sodium bicarbonate was weighed and dissolved in deionized water to prepare a 0.5 mol / L sodium bicarbonate solution. The pH value was adjusted to 9.0 with sodium hydroxide. Manganese acetate and zinc acetate were added to the sodium bicarbonate solution, and 100 g of bentonite was added. An equal volume of deionized water was added as a medium, and low-speed ball milling at 200 rpm for 30 min and autothermal ball milling at 400 rpm for 50 min were performed in sequence to obtain the piezoelectric photocatalytic antibacterial material.

[0080] The piezoelectric photocatalytic antibacterial material prepared in this example was subjected to the same antibacterial performance test as in Example 1.

[0081] The test results show that the sterilization rate of the piezoelectric photocatalytic antibacterial material prepared in this example under the suggestive conditions is about 82.6%, the sterilization rate of the piezoelectric photocatalytic antibacterial material prepared in this example under the photocatalytic test conditions is about 93.3%, and the sterilization rate of the piezoelectric photocatalytic antibacterial material prepared in this example in the photocatalytic swelling test is greater than 99%.

[0082] The above characterization tests show that during the preparation process of ball milling with deionized water as the medium, the MZO nano-quantum dot structure agglomerates due to factors such as agglomeration, and the specific surface area decreases rapidly, resulting in a significant decrease in the actual contact sterilization and direct photocatalytic sterilization efficiency in the absence of external force. However, after swelling, it can still exhibit excellent piezoelectric photocatalytic antibacterial properties.

[0083] Comparative Example 2

[0084] A piezoelectric photocatalytic antibacterial material is prepared by the following method:

[0085] According to the stoichiometric formula Mn 0.5 Zn 0.5 Manganese acetate and zinc acetate were taken separately, with a total of 60 mmol of manganese acetate and zinc acetate weighed. Subsequently, 0.135 mol of sodium carbonate was weighed and dissolved in deionized water to prepare a 0.5 mol / L sodium carbonate solution. The pH value was adjusted to 9.0 with acetic acid. Manganese acetate and zinc acetate were added to the sodium bicarbonate solution, and 100 g of bentonite was added. An equal volume of polyethylene glycol was added as a medium, and the mixture was subjected to low-speed ball milling at 200 rpm for 30 min and autothermal ball milling at 400 rpm for 50 min to obtain the piezoelectric photocatalytic antibacterial material.

[0086] The piezoelectric photocatalytic antibacterial material prepared in this example was subjected to the same antibacterial performance test as in Example 1.

[0087] The test results show that the sterilization rate of the piezoelectric photocatalytic antibacterial material prepared in this example under the suggestive conditions is about 83.9%, the sterilization rate of the piezoelectric photocatalytic antibacterial material prepared in this example under the photocatalytic test conditions is about 93.6%, and the sterilization rate of the piezoelectric photocatalytic antibacterial material prepared in this example in the photocatalytic swelling test is about 98.9%.

[0088] It can be seen from the above characterization tests that the present invention simply replaces sodium bicarbonate with sodium carbonate, and the actual sodium treatment of bentonite has a very significant decline in effect. This is mainly due to the improper sodium treatment, which leads to a significant decrease in the MZO quantum dot immobilization rate, thus showing a significant decline in the antibacterial and sterilization effects under the three conditions.

[0089] Comparative Example 3

[0090] A piezoelectric photocatalytic antibacterial material is prepared by the following method:

[0091] According to the stoichiometric formula Mn 0.5 Zn 0.5Manganese acetate and zinc acetate were weighed separately, totaling 60 mmol. 0.135 mol of sodium bicarbonate was then dissolved in deionized water to prepare a 0.5 mol / L sodium bicarbonate solution. The pH was adjusted to 9.0 with sodium hydroxide. The manganese acetate and zinc acetate were then added to the sodium bicarbonate solution, along with 100 g of bentonite. An equal volume of deionized water was then added as a medium. The mixture was then autogenously ball-milled at 400 rpm for 80 minutes to obtain the piezoelectric photocatalytic antibacterial material. The piezoelectric photocatalytic antibacterial material prepared in this example was subjected to the same antibacterial performance test as in Example 1.

[0092] The test results show that the sterilization rate of the piezoelectric photocatalytic antibacterial material prepared in this example under the suggestive conditions is about 81.9%, the sterilization rate of the piezoelectric photocatalytic antibacterial material prepared in this example under the photocatalytic test conditions is about 93.1%, and the sterilization rate of the piezoelectric photocatalytic antibacterial material prepared in this example in the photocatalytic swelling test is about 97.8%.

[0093] It can be seen from the above characterization tests that when high-speed self-heating ball milling is directly carried out, the sodiumization process is affected, which actually affects the effective immobilization of MZO quantum dots, resulting in defects similar to those in Comparative Example 2. The antibacterial and sterilization effects under the three experimental conditions are significantly reduced.

[0094] Comparative Example 4

[0095] A piezoelectric photocatalytic antibacterial material is prepared by the following method:

[0096] According to the stoichiometric formula Mn 0.5 Zn 0.5 Manganese acetate and zinc acetate were weighed separately, totaling 60 mmol. 0.135 mol of sodium bicarbonate was then dissolved in deionized water to prepare a 0.5 mol / L sodium bicarbonate solution. The pH was adjusted to 9.0 with sodium hydroxide. The manganese acetate and zinc acetate were then added to the sodium bicarbonate solution, along with 100 g of bentonite. An equal volume of deionized water was then added as a medium. The mixture was ball-milled at 200 rpm for 90 minutes to obtain the piezoelectric photocatalytic antibacterial material. The piezoelectric photocatalytic antibacterial material prepared in this example was subjected to the same antibacterial performance test as in Example 1.

[0097] The test results show that the sterilization rate of the piezoelectric photocatalytic antibacterial material prepared in this example under the suggestive conditions is about 85.2%, the sterilization rate of the piezoelectric photocatalytic antibacterial material prepared in this example under the photocatalytic test conditions is about 96.7%, and the sterilization rate of the piezoelectric photocatalytic antibacterial material prepared in this example in the photocatalytic swelling test is greater than 99%.

[0098] The above characterization tests show that under low-speed ball milling conditions, the quantum dot structure is difficult to effectively disperse, making it difficult for the MZO system quantum dots to enter and diffuse between the bentonite layers, resulting in a decrease in the actual fixed loading rate. However, the effect is slightly better than that of Comparative Examples 2 and 3, but still lower than that of Example 1.

Claims

1. A method for preparing a piezoelectric photocatalytic antibacterial material, characterized in that: The method comprises: According to the stoichiometric formula Mn x Zn 1-x O. Take manganese acetate and zinc acetate separately, add manganese acetate and zinc acetate into sodium bicarbonate solution and add bentonite at the same time; adjust the pH value of the sodium bicarbonate solution to 8.5-9.5; adding polyethylene glycol as a medium, and sequentially performing low-speed ball milling at 200 rpm and autothermal ball milling at 400 rpm to obtain the piezoelectric photocatalytic antibacterial material; Among them: 0<x<1.

2. The method for preparing a piezoelectric photocatalytic antibacterial material according to claim 1, characterized in that: The sodium bicarbonate content in the sodium bicarbonate solution is 1.2 to 1.5 mmol / g bentonite.

3. The method for preparing a piezoelectric photocatalytic antibacterial material according to claim 1, characterized in that: The total molar amount of manganese and zinc contained in the manganese acetate and zinc acetate is 0.5-0.8 mmol / g bentonite.

4. The method for preparing a piezoelectric photocatalytic antibacterial material according to claim 1, characterized in that: The low-speed ball milling time is 25 to 35 minutes.

5. The method for preparing a piezoelectric photocatalytic antibacterial material according to claim 1, characterized in that: The autothermal ball milling time is 45 to 60 minutes.

6. A piezoelectric photocatalytic antibacterial material prepared by the method according to any one of claims 1 to 5.

7. An application of the piezoelectric photocatalytic antibacterial material according to claim 6, characterized in that: The piezoelectric photocatalytic antibacterial material is used for making cat litter.

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