Passive active oxygen generating device

Abstract

The invention relates to a passive active oxygen generating device which is characterized by comprising a shell, a substrate and a reaction film which are arranged in sequence. Visible light in the environment enters the reaction film and is absorbed by the reaction film, a large number of vacancies and electrons are generated, and the vacancies and electrons react with water or oxygen molecules in the surrounding environment to generate active oxygen. The active oxygen is a broad-spectrum bactericide, can kill bacterial propagules, bacterial spores, viruses and fungi, also has a good killing effect on protozoa and oocysts thereof, and also can destroy bacterial toxins, hepatitis B surface antigens and the like. The device can be applied to sterilization and disinfection of object surfaces, air and the like, and has the advantages of no need of additional energy sources, high efficiency, lasting performance and the like.

Description

Technical Field

[0001] The present invention relates to a passive active oxygen generating device, characterized in that it comprises a shell, a substrate and a reaction membrane arranged in sequence. Visible light in the environment enters the reaction membrane and is absorbed by it, generating a large number of vacancies and electrons, which react with water or oxygen molecules in the surrounding environment to generate active oxygen. Active oxygen is a broad-spectrum bactericide that can kill bacterial propagules, bacterial spores, viruses, fungi, and has a good killing effect on protozoa and their oocysts, and can also destroy bacterial toxins, hepatitis B surface antigens, etc. Background Art

[0002] Reactive oxygen refers to chemically active oxygen-containing atoms or radicals, including superoxide anion free radicals (O2 - ), hydrogen peroxide (H2O2), singlet oxygen ( 1 O2), hydroxyl radical (·OH), alkane peroxide free radical, lipid peroxide free radical, etc.

[0003] Reactive oxygen is a strong oxidant that has a wide range of killing effects on microorganisms including bacteria, spores, viruses, fungi, etc. Its killing rate is 600-3000 times faster than chlorine. The killing effect of active oxygen on microorganisms mainly depends on its strong oxidizing effect. Active oxygen is a broad-spectrum bactericidal agent that can kill bacterial propagules, bacterial spores, viruses, fungi, and has a good killing effect on protozoa and their oocysts. It can also destroy bacterial toxins and hepatitis B surface antigen. In recent years, due to the development of science and technology, there have been new developments in the application of active oxygen in disinfection, such as disinfection of water, air, surface of objects, food, vegetables, etc., and it is also used for sterilization in industry and agriculture. The killing effect of active oxygen on microorganisms mainly depends on its strong oxidizing effect.

[0004] The main methods of producing active oxygen at present are to use ultraviolet rays to decompose hydrogen peroxide and to use photocatalysts to decompose water and oxygen molecules. The decomposition of hydrogen peroxide by ultraviolet rays produces ·OH through the following reaction process: H2O2+hv→2·OH……………………(1)

[0005] However, the molar extinction coefficient of hydrogen peroxide is very low (about 19 dm 3 ·mol -1 ), its production efficiency is very low, so this method is not suitable for high-efficiency generation of active oxygen.

[0006] On the other hand, the method of generating active oxygen by irradiating photocatalytic materials with ultraviolet light is to utilize the photocatalytic materials to absorb the incident light, generate electrons and vacancies, which react with water or oxygen molecules in the surrounding environment to generate active oxygen. Typical photocatalytic materials such as TiO2 are semiconductor materials, and their band structure consists of a low-energy valence band filled with electrons and an empty high-energy conduction band, with a band gap between the valence band and the conduction band. When the semiconductor is irradiated with light with energy equal to or greater than the band gap width, the electrons in the valence band will be excited to jump to the conduction band and accumulate on the conduction band. At the same time, positively charged holes are generated on the valence band, forming electron-hole pairs with the electrons excited to the conduction band. When the photocatalytic material is excited by light, the electrons and holes are separated and migrate to different positions on the surface of the particle, respectively reducing and oxidizing the substances adsorbed on its surface. The photogenerated holes have strong oxidizing properties and can capture the electrons of water in the environment on the surface of the material, oxidizing it to ·OH: h + +OH - →·OH………………………………(1)

[0007] The photogenerated electrons in the conduction band have strong reducing properties and can reduce O2 adsorbed on the surface of the material to O2 - :

[0008] At the same time O2 - Reaction with H2O can produce ·OOH, thus producing H2O2: 2·OOH→H2O2+O2……………………(4)

[0009] H2O2 can react with electrons and O2 - The reaction produces OH: H2O2+e - → OH+OH - ………………………………(5)

[0010] However, since photocatalytic materials generally have a large bandgap and can only be excited by ultraviolet and near-ultraviolet light in the solar spectrum, they must be excited using a light source such as an ultraviolet lamp.

[0011] In summary, both of these commonly used methods require the use of ultraviolet lamps (extra energy), which are harmful to the human body and pose safety issues. They can only be used in unmanned environments and cannot continuously produce active oxygen in an environment that is safe for the human body. Summary of the invention

[0012] In view of the problems existing in the prior art, the present invention proposes an active oxygen generating device which works under passive conditions and relies on ambient visible light.

[0013] The essence of the present invention is to use doped titanium dioxide instead of ordinary titanium dioxide as a photocatalytic material, which also has efficient photocatalytic effect under the irradiation of visible light, and reacts with moisture and oxygen in the surrounding air to produce active oxygen. It is well known that the band gap of ordinary titanium dioxide is relatively large (about 3.2eV, corresponding to a wavelength of 387nm, in the ultraviolet band), and it is unable to generate electrons in the conduction band and valence band holes under visible light irradiation, so it does not have photocatalytic ability. However, when nitrogen is introduced into titanium dioxide, that is, nitrogen-doped titanium dioxide, a new intermediate gap energy state is formed, that is, the N 2p energy band above the O 2p valence band, so that the band gap of titanium dioxide is reduced to about 2.5eV (equivalent to a wavelength of 496nm, in the visible light band), thereby red-shifting the optical absorption peak to the visible light region. Therefore, nitrogen-doped titanium dioxide has a photocatalytic function even under the irradiation of visible light only, and can react with moisture and oxygen in the surrounding air to produce active oxygen. The process of generating active oxygen can be described by the following equation: h + +OH - →·OH………………………………(1) 2·OOH→H2O2+O2……………………(4) H2O2+e - → OH+OH - …………………………(5)

[0014] The present invention is achieved through the following technical solutions:

[0015] The present invention proposes a passive active oxygen generating device, such as Figure 1 As shown, it includes a housing 101, a substrate 102, and a reaction film 103, which are arranged in sequence, and integrates the above components into one. Visible light in the environment enters the reaction film and is absorbed by it, generating a large number of vacancies and electrons, which react with water or oxygen molecules in the surrounding environment to generate active oxygen.

[0016] The passive active oxygen generation device proposed by the present invention has the advantages of safety, simplicity and no extra energy consumption. At present, active oxygen is usually generated by high-voltage discharge or ultraviolet irradiation of photocatalytic materials and directly generated, but high-voltage discharge requires an additional energy source and has safety issues, and excessive ultraviolet rays are harmful to the human body. The present invention can effectively solve the above problems.

[0017] Furthermore, the main material of the reaction film includes nitrogen-doped titanium dioxide, zinc-doped titanium dioxide, titanium dioxide, zinc oxide, silver oxide and other photocatalytic materials, and the photocatalytic effect is used to ensure that the antibacterial rate reaches more than 99%.

[0018] Furthermore, the photocatalytic material is in powder form, and the particle size is between 2nm and 100nm.

[0019] Furthermore, the auxiliary material of the reaction membrane is a binder, including water-based paint, lacquer, and latex binder.

[0020] Furthermore, the thickness of the reaction film is between 0.01 mm and 1 mm.

[0021] Furthermore, the shell needs to have good mechanical strength, certain corrosion resistance and other properties. The shell material is a polymer or metal, including polymethyl methacrylate (PMMA), polystyrene (PS), polycarbonate (PC), polyethylene (PE), acrylonitrile-butadiene-styrene copolymer (ABS), polypropylene (PP), polyvinyl chloride (PVC), stainless steel, zinc, aluminum, copper, and chromium.

[0022] Furthermore, the substrate needs to have a thermal expansion coefficient close to that of the reaction film, and the substrate material is metal or polymer material to ensure that it can closely contact with the reaction film without gaps.

[0023] Furthermore, the shape of the shell includes sheet, cylinder, box, and sphere.

[0024] The present invention has the following beneficial effects:

[0025] (1) Safe and reliable: Visible light is used to irradiate photocatalytic materials to produce active oxygen, without the need for ultraviolet rays that are harmful to the human body; (2) Energy saving: The photocatalytic effect is produced by using natural light from the environment, without the need for additional energy; (3) Diversified shapes: The shape of the device can be flat, curved, and can be a two-dimensional structure or a three-dimensional structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The structure diagram of a passive active oxygen generation device is shown in FIG. 1 , wherein (101) is a housing, (102) is a substrate, and (103) is a reaction membrane.

[0027] Figure 2 The figure is a schematic diagram of the working principle of releasing active oxygen after water and oxygen are catalyzed by the active oxygen generator of the present invention using ambient visible light.

[0028] Figure 3 UV-visible absorption spectra of titanium dioxide and zinc-doped titanium dioxide nanomaterials.

[0029] Figure 4 This is the UV-visible absorption spectrum of nitrogen-doped titanium dioxide nanomaterials.

[0030] Figure 5 Air purification test report for a passive active oxygen generating device DETAILED DESCRIPTION

[0031] The following are specific embodiments of the present invention and are combined with the attached Figure 2 , the technical solution of the present invention is further described. However, the present invention is not limited to these embodiments.

[0032] To build the reactive oxygen generator, follow these steps:

[0033] (1) First, a polymethyl methacrylate plate with a thickness of 3 mm and a side length of 30 mm was selected as the device shell to serve as the frame of the substrate; a polycarbonate plate with a thickness of 1 mm was selected as the substrate to serve as the substrate of the reaction membrane.

[0034] (2) Select nitrogen-doped TiO2 nanopowder as the main material of the reaction membrane ceramic slurry and select water-based paint as the binder.

[0035] (3) To ensure that the reaction film absorbs enough visible light and is in full contact with the air, a ceramic slurry of 0.02-0.04 mm is evenly applied on one side of the polycarbonate substrate to give it a larger specific surface area and allow for full reaction.

[0036] (4) Apply acrylic pressure-sensitive adhesive on the other side of the polycarbonate substrate to ensure close contact between the polycarbonate substrate and the polymethyl methacrylate plate without gaps.

[0037] (5) Assemble the panels formed in the above steps into a cube with a side length of 30 mm.

[0038] Figure 2 It shows that when the reaction film is irradiated with visible light, the electrons in the valence band will be excited to jump to the conduction band and gather on the conduction band. At the same time, positively charged holes are generated on the valence band, forming electron-hole pairs with the electrons excited to the conduction band. After separation, the electrons and holes migrate to different positions on the particle surface, respectively reducing and oxidizing the substances adsorbed on the surface, converting H2O and OH - Oxidize to OH, reduce O2 and O3 to O2 - It further produces H2O2, which decomposes to produce ·OH, thus achieving the required active oxygen generation function.

[0039] like Figure 3 and Figure 4As shown, the absorbance of zinc-doped TiO2 and nitrogen-doped TiO2 nanopowders in the visible light region is greater than that of TiO2 nanopowders, so zinc-doped TiO2 or nitrogen-doped TiO2 nanopowders are used as the main material of the reaction film.

[0040] The passive active oxygen generating device described in the present invention was tested for air purification effect. The ambient temperature was controlled at 23.1°C and the relative humidity was 64%. Staphylococcus aureus was used as the test strain. 3 The aerosol chamber was filled with a fan while spraying. After spraying, the fan continued to stir for 5 minutes, and then it was left to stand for 5 minutes. The number of positive control bacteria in the air of the aerosol chamber reached 5.0×10 4 cfu / m 3 -5.0×10 6 cfu / m 3 . A liquid impact microbial aerosol sampler was used to sample the aerosol chambers of the test group and the control group before disinfection. The sampling was carried out at a flow rate of 11L / min, the volume of the sampling liquid was 20mL, and the sampling time for both the test group and the control group was 2min. The prototype was powered on and the fan in the cabin was turned on. After 2h of action, the aerosol chamber after disinfection was sampled at the same flow rate. The sampling time for both the test group and the control group was 2min. The collected plates were placed in a 37°C incubator and incubated for 48h to observe the results. The experiment was repeated 3 times, and the test results are listed in Table 1. Figure 5 As shown, the average sterilization rate of the test samples was as high as 97.2%, which was much higher than its natural extinction rate of 53.9%.

[0041] Table 1 2 h culture results of Staphylococcus albus in the passive reactive oxygen generation device.

[0042]

[0043] It should be understood by those skilled in the art that the embodiments of the present invention described above and shown in the accompanying drawings are only examples and do not limit the present invention. The purpose of the present invention has been fully and effectively achieved. The functional and structural principles of the present invention have been demonstrated and explained in the embodiments, and the embodiments of the present invention may be deformed or modified in any way without departing from the principles.

Claims

1. A passive active oxygen generating device, characterized in that: The invention comprises a shell, a substrate and a reaction film. The reaction film is placed on the substrate, and the shell includes the reaction film and the substrate.

2. A passive active oxygen generating device according to claim 1, characterized in that: The reaction film is composed of a photocatalytic material and a binder.

3. A passive active oxygen generating device according to claim 2, characterized in that: The upper limit of the light absorption range of the photocatalytic material is increased to 500nm.

4. A passive active oxygen generating device according to claim 2, characterized in that: The photocatalytic material is one of the following materials: nitrogen-doped titanium dioxide, zinc-doped titanium dioxide, titanium dioxide, zinc oxide, and silver oxide.

5. A passive active oxygen generating device according to claim 2, characterized in that: The photocatalytic material is in powder form, and the particle size is between 2nm and 100nm.

6. A passive active oxygen generating device according to claim 2, characterized in that: The binder is one of the following materials: water-based paint, lacquer, latex binder.

7. A passive active oxygen generating device according to claim 1, characterized in that: The ratio of the photocatalytic material to the binder in the reaction film is 1:99 to 1:

9.

8. A passive active oxygen generating device according to claim 1, characterized in that: The thickness of the reaction film is between 0.01 mm and 1 mm.

9. A passive active oxygen generating device according to claim 1, characterized in that: The substrate is one or more of the following materials: polycarbonate (PC), acrylonitrile-butadiene-styrene copolymer (ABS), aluminum, polyethylene (PE), and polypropylene (PP).

10. The passive active oxygen generating device according to claim 1, characterized in that: The shape of the shell is one of the following shapes: sheet, cylinder, box, sphere.

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