Indoor ozone-degrading material and preparation method thereof

Abstract

The present application relates to the technical field of room temperature ozone purification, and particularly relates to an indoor ozone degradation material and a preparation method thereof.A specific technical scheme is as follows: a preparation method of an indoor ozone degradation material, comprising the following steps: (1) loading manganese dioxide on activated carbon fiber after surface activation to obtain a precursor 1; (2) immersing the precursor 1 in prepared visible light sensitive TiO2 sol, and loading TiO2 on the precursor 1 through drying and calcination.The present application combines activated carbon fiber and catalysts (manganese dioxide and titanium dioxide), improves the ozone adsorption capacity, and decomposes ozone into oxygen through catalysis, thereby avoiding secondary pollution.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of room temperature ozone purification technology, in particular to an indoor ozone degradation material and a preparation method thereof. BACKGROUND

[0002] With the acceleration of urbanization and the improvement of people's living standards, the indoor environmental quality has been generally concerned. The main sources of indoor ozone are outdoor atmosphere, indoor electrical equipment and indoor photochemical reaction, etc. The outdoor atmospheric ozone mainly comes from outdoor photochemical reaction, and its influence on indoor ozone is mainly determined by the control efficiency of atmospheric precursors NOx and VOCs and the indoor and outdoor permeation amount; various types of electronic equipment in the room, such as computers, printers, copiers, etc., are also the main sources of indoor ozone, and the average mass concentration of ozone is 0.461mg / m 3 when a (8x6x3m) indoor room opens 1 printer for 5 minutes, and 0.879mg / m 3 when 3 printers are opened.

[0003] In view of the health risk of ozone, China has formulated the outdoor atmospheric ozone standard (the secondary standard is 8h concentration 0.16mg / m 3 ), the indoor air ozone standard (1h concentration 0.16mg / m 3 ), and the standard for using ozone for sterilization and deodorization equipment (the special requirements for antibacterial, degerming and purifying air purifiers for household and similar purposes in GB21551.3-2010 require that the ozone concentration (5cm from the air outlet) be ≤0.10mg / m 3 ; the ozone gas residual amount in YY0215-2008 Medical Ozone Disinfection Cabinet shall not be greater than 0.16mg / m 3 ; the 10-minute average ozone concentration every two minutes at a distance of 20cm from the cabinet in GB17988-2008 Safety and Hygiene Requirements for Tableware Disinfection Cabinet shall not exceed 0.2mg / m 3 ; the 1h average maximum allowable ozone concentration in the indoor air environment when the sterilizer is working in GB28235-2011 Safety and Hygiene Standard for Ultraviolet Air Disinfection Device is 0.1mg / m 3 ; and the allowable ozone concentration of indoor air in the presence of people in WS / T367-2012 Disinfection Technical Specification for Medical Institutions is 0.16mg / m 3 . However, the monitoring data shows that the common indoor ozone concentration in the living environment is (0.05-0.1mg / m 3 ), which is far lower than the values specified in the above standards. The EPA study shows that long-term exposure to 0.05mg / m 3The prevalence of chronic obstructive pulmonary disease (COPD) significantly increased, and the annual decline rate of lung function increased by 3.2% in the ozone environment. The Indoor Air Quality Standard GB / T18883-2022 only limits the 1h concentration of ozone for acute exposure risk (0.16mg / m 3 ), and there is no standard for chronic exposure risk under long-term low concentration.

[0004] Ozone has strong oxidizing properties. Even in a low-concentration environment, long-term exposure can have many adverse effects on human health. It can stimulate the respiratory mucosa, cause coughing, wheezing, sore throat, and other symptoms. For people with respiratory diseases, such as asthma patients and chronic obstructive pulmonary disease patients, the harm of ozone is more significant, which can exacerbate the condition, increase the frequency of medical treatment, and increase medical costs. Ozone can also irritate the eyes, causing dryness, redness, tearing, and other discomforts. Long-term exposure may even affect vision. In addition, indoor ozone can also damage indoor items, accelerate the aging and damage of furniture, electrical appliances, and other items, reducing their service life and causing economic losses to people.

[0005] Current common ozone removal technologies include (1) activated carbon adsorption: activated carbon has a rich interconnected pore structure inside, with a large specific surface area, which can adsorb gas molecules inside the pores through van der Waals forces. This physical adsorption method has no selectivity, and as the use time increases, the adsorption sites of activated carbon are gradually occupied by various gas molecules. Due to the limited adsorption capacity, once the adsorption sites reach saturation, the adsorption effect will decrease sharply, and desorption treatment is needed, but the desorption efficiency is low, and the regeneration capacity is poor. Secondly, under some specific environmental conditions such as temperature rise and pressure change, the adsorbed gas molecules will be desorbed and released back into the indoor air, making activated carbon a source of pollution. Among the many gaseous pollutants in the indoor environment, the ozone concentration is relatively low, and activated carbon adsorption is obviously not targeted. (2) UV irradiation method: UV mainly has the effect of killing bacteria and can also decompose ozone. This method requires specific wavelength UV, which consumes a lot of energy and can harm the human body, limiting its widespread application indoors. (3) Thermal decomposition method: Higher temperatures are needed to reduce the reversibility of the reaction of ozone decomposition into oxygen, which not only increases energy consumption but also may cause other safety problems. (4) Catalytic decomposition method: Professional air purification equipment uses specific catalysts such as manganese dioxide to decompose ozone, which has a higher removal effect on 1.96-19.6mg / m 3 concentration of ozone at 20-25℃, but slight fluctuations in temperature can change the crystal structure and electronic properties of the catalyst, affecting its catalytic activity. Metal oxides such as titanium dioxide can also decompose ozone under photocatalytic action, but this technology is currently mainly used for VOCs removal, and ozone and VOCs coexist in the environment, which has more reactivity to VOCs.

[0006] The current market indoor air purifier is mainly for small space using filtration, adsorption, ultraviolet light and other methods to eliminate particulate matter and bacteria virus, the treatment method for gaseous pollutants such as photocatalysis, low temperature plasma, adsorption, electrostatic, catalysis and other methods have the disadvantages of low efficiency, high energy consumption. Ozone is one of the important indoor gaseous pollutants, and there is no special function unit for efficient treatment of indoor ozone gas in the current air purifier.

[0007] Indoor ozone due to complex sources, low concentration but high pathogenicity, its efficient degradation method needs to be developed. People's awareness of the degree of ozone danger and harm is low, and they do not consciously take active prevention and control. Especially the desktop workstation, because of the concentrated operation of electrical appliances, it has become the main position of indoor ozone. SUMMARY

[0008] In view of the shortcomings of the prior art, the present application provides an indoor ozone degradation material and a preparation method thereof, which can be applied to the local personal protective equipment of the workstation to remove ozone and achieve the effect of oxygen bar.

[0009] To achieve the above object, the technical scheme is as follows:

[0010] The application discloses a preparation method of an indoor ozone degradation material, comprising the following steps:

[0011] (1) loading manganese dioxide on the surface-activated activated carbon fiber to obtain a precursor 1;

[0012] (2) preparing a visible light sensitive titanium dioxide (TiO2) sol by a sol-gel method, immersing the precursor 1 in the prepared visible light sensitive TiO2 sol, making the TiO2 sol fully penetrate into the pores of the activated carbon fiber, and loading the TiO2 on the precursor 1 firmly through drying and calcining.

[0013] Preferably, the surface activation process of the activated carbon fiber is as follows: the dried activated carbon fiber is placed in a mixed solution composed of sulfuric acid with a concentration of 1-3 mol / L and hydrogen peroxide with a volume fraction of 30%, and is subjected to ultrasonic treatment at 50-70 DEG C for 30-60 minutes, the ultrasonic power is 200-400 W, and the volume ratio of the sulfuric acid to the hydrogen peroxide is 1:1-1:2.

[0014] Preferably, the specific surface area of the activated carbon fiber is 500-1000 m 2 / g, and the fiber diameter is 8-12 μm.

[0015] Preferably, the process of loading manganese dioxide on the activated carbon fiber is as follows: the activated carbon fiber is immersed in a manganese nitrate solution with a concentration of 0.3-0.6 mol / L, stirred at 40-60°C for 2-4 hours at a stirring speed of 300-500 rpm, filtered, dried at 100-120°C for 6-10 hours, and then calcined at 350-500°C for 3-5 hours.

[0016] Preferably, the process of preparing the visible light sensitive TiO2 sol is as follows: the organic dye, TiO2 and carbon source are mixed to obtain the visible light sensitive TiO2 sol.

[0017] Preferably, the carbon source is urea or glucose, and the organic dye is phthalocyanine or porphyrin; the mass of the organic dye is 1%-2% of the mass of TiO2, and the mass of the carbon source is the same as that of TiO2.

[0018] Preferably, the process of preparing TiO2 is as follows: tetrabutyl titanate is mixed with ethanol, the pH is adjusted to 3-4, and the mixture is stirred for 2 hours to form a transparent sol. In the process of preparing the visible light sensitive TiO2 sol, the organic dye (such as phthalocyanine or porphyrin) and the carbon source (such as urea or glucose) are added to the transparent sol and stirred uniformly. Then, the mixture is ultrasonically treated for 1-2 hours to obtain the visible light sensitive TiO2 sol.

[0019] Preferably, in step (2), the precursor 1 is immersed in the visible light sensitive TiO2 sol, stirred at 50-70°C for 2-3 hours, so that the TiO2 sol can fully penetrate into the pores of the activated carbon fiber and contact the MnO2 that has been loaded. After filtration, the mixture is dried at 100-120°C for 6-8 hours, and then calcined at 300-400°C for 2-3 hours, so that the TiO2 is firmly loaded on the precursor 1.

[0020] Correspondingly, the indoor ozone degradation material prepared by the above method is obtained.

[0021] The present application has the following advantages:

[0022] 1. High efficiency in removing ozone: the combination of the activated carbon fiber and the catalyst (manganese dioxide and titanium dioxide) not only improves the adsorption capacity of ozone, but also decomposes the ozone into oxygen through catalysis, thereby avoiding secondary pollution. Moreover, the catalyst (such as manganese dioxide and titanium dioxide) is loaded on the activated carbon fiber to realize the dual function of adsorption and catalytic degradation. The activated carbon fiber adsorbs ozone and increases the local concentration of ozone, so that the concentration of ozone can be maintained at the optimal concentration (1.96-19.6 mg / m3) for the catalytic degradation of manganese dioxide. 3) so that manganese dioxide can efficiently decompose ozone into oxygen. The modified titanium dioxide compounded with manganese dioxide catalyzes the degradation of volatile organic compounds adsorbed by the activated carbon fiber, allowing it to give up more adsorption sites to ozone molecules, thereby "regenerating the activated carbon". At the same time, the synergistic effect of the catalyst and the activated carbon fiber is achieved. The activated carbon fiber adsorbs ozone and can maintain the ozone concentration in its pores at 9.8mg / m 3 Around 10000 is the optimal concentration for manganese dioxide catalytic degradation of ozone, maintaining its high efficiency. At room temperature (10-30°C), the ozone removal rate can reach 80-90%, and it can maintain high removal efficiency (>85%) for up to 1000-2000 hours (continuous operation time).

[0023] 2. Efficient catalysis of low concentration ozone at room temperature: By optimizing the pore structure and surface treatment of activated carbon fibers, the ozone concentration in the pores is maintained at the optimal concentration for catalytic degradation of manganese dioxide (1.96-19.6 mg / m 3 ), so that the ozone removal efficiency of manganese dioxide can reach more than 80% at room temperature (10-30°C) and is not affected by temperature fluctuations.

[0024] 3. Extended service life: Through the synergistic effect of activated carbon fiber and catalyst, the adsorption capacity of activated carbon only decreases by about 10%, significantly extending its service life. After 100 hours of continuous operation, it can still maintain a high ozone removal capacity (>80%), and its service life can reach 1-2 years (equipment operation 3-6 hours per day).

[0025] 4. Multifunctional Purification: This invention not only efficiently removes ozone but also degrades VOCs (such as formaldehyde and benzene) under visible light conditions using a titanium dioxide catalyst, achieving a degradation efficiency of 90-95%. Simultaneously, it produces 27.34-274.38 mL / h of oxygen, acting as an oxygen bar and achieving multifunctional purification.

[0026] 5. Wide range of applications: The present invention is applicable to a variety of indoor environments (such as homes, offices, schools, etc.), and can work efficiently under room temperature and relative humidity of 30-70%, with a wide range of applications and high safety.

[0027] 6. Material processing and structure optimization: Through acid and alkali treatment, ultrasonic cavitation and other processes of activated carbon fiber, its specific surface area (800-1500m 2 / g) and pore diameter (0.5-2nm), enhancing its adsorption capacity. At the same time, through tableting, the contact area and contact time between gas and filler are increased, further improving purification efficiency.

[0028] 7. Environmental protection and safety: the present application adopts polypropylene (PP) material to make the shell, which is non-toxic, odorless, resistant to chemical corrosion, and meets the environmental protection requirements. The entire purification process is carried out at room temperature without high temperature or ultraviolet light, which is safe and reliable. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 It is a schematic diagram of the purification device. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0031] If not specifically indicated, the technical means used in the examples is the conventional means familiar to those skilled in the art.

[0032] Embodiment 1

[0033] The present application discloses a preparation method of an indoor ozone degradation material, which embeds activated carbon fiber with a catalyst, and specifically includes the following steps:

[0034] 1. Raw material pretreatment

[0035] High-purity activated carbon fiber (ACF) with rich pore structure and high specific surface area is selected, and the initial specific surface area thereof is preferably 500-1000 m 2 / g, the fiber diameter range is 8-12 μm, the interlaced layer of the fiber has a thickness of 0.5-1.0 mm, and has excellent toughness (tensile strength can reach 50-200 MPa). First, the activated carbon fiber is cleaned by soaking in deionized water for 2-4 hours, and the surface impurities are removed by constant stirring during the soaking. Then, the activated carbon fiber is filtered and dried at 105-110°C for 8-12 hours to remove the water, impurities and volatile organic compounds adsorbed on the surface of the activated carbon fiber, so as to ensure the uniformity and effectiveness of the subsequent modification process.

[0036] 2. Surface activation

[0037] The dried activated carbon fiber is placed in a mixed solution composed of sulfuric acid with a concentration of 1-3 mol / L (preferably 1.8 mol / L) and hydrogen peroxide with a volume fraction of 30% (volume ratio of 1:1-1:2), and ultrasonic treatment is performed at 50-70°C for 30-60 minutes. The ultrasonic power is set to 200-400 W, the solution is fully contacted with the surface of the activated carbon fiber through ultrasonic cavitation, the oxidation effect is enhanced, and at the same time, the specific surface area of the activated carbon fiber is increased to 800-1500 m2 The pore diameter is 0.5-2 nm. This step can introduce abundant active functional groups (such as carboxyl, hydroxyl and carbonyl) on the surface of the activated carbon fiber and increase the surface roughness, providing a good foundation for subsequent catalyst loading. The results show that the oxygen-containing functional group content of the activated carbon fiber after surface activation can be increased by 20-40%, and the light transmittance (visible light band) of the fiber interlaced layer is 60-70%, indicating that it has moderate light transmittance, and its ozone adsorption capacity reaches 100-500 mg / g.

[0038] 3. Titanium dioxide modification (visible light sensitization)

[0039] Visible light-sensitive titanium dioxide (TiO2) is prepared by sol-gel method. Tetrabutyl titanate (Ti(OC4H9)4) is mixed with ethanol at a volume ratio of 1:10, and the viscosity of the sol is controlled. Lower viscosity helps the sol to penetrate better into the pores of the activated carbon fiber. Then a small amount of nitric acid (pH adjusted to 3-4) is added, and stirred for 2 hours to form a transparent sol. Subsequently, 1%-2% of TiO2 mass of organic dye (such as phthalocyanine or porphyrin) and the same mass of carbon source (such as urea or glucose) as TiO2 are added to the sol and stirred uniformly. Then ultrasonic treatment is performed for 1-2 hours to obtain TiO2 sol with visible light sensitivity.

[0040] The present application prepares TiO2 sol with visible light sensitivity by sol-gel method. Organic dyes (such as phthalocyanine and porphyrin) are attached to the surface of TiO2, and the dye's ability to absorb visible light is used to excite electrons to inject into the conduction band of TiO2, achieving visible light sensitization. Carbon doping or carbon coating is used to improve the physical and chemical properties of TiO2, thereby enhancing its photocatalytic performance. This enables efficient catalytic degradation of VOCs molecules by titanium dioxide under visible light conditions. VOCs molecules with a diameter of 0.4-1 nm, such as formaldehyde and benzene, are competitive molecules for ozone molecules at the above-mentioned activated carbon fiber adsorption sites. The degradation ability of TiO2 sol with visible light sensitivity for VOCs is used to release the adsorption sites of the above-mentioned activated carbon fiber, extending the service life of the activated carbon fiber for ozone removal.

[0041] 4. Catalyst loading

[0042] 4.1 Manganese dioxide (MnO2) loading

[0043] A manganese nitrate (Mn(NO3)2) solution with a concentration of 0.3-0.6 mol / L is prepared. The surface-activated activated carbon fiber is immersed in the manganese nitrate solution, and is mechanically stirred at 40-60°C for 2-4 hours at a stirring speed of 300-500 rpm, so that the manganese nitrate is fully penetrated into the pores of the activated carbon fiber. Then, the sample is filtered, dried at 100-120°C for 6-10 hours, and transferred to a muffle furnace for calcination at 350-500°C for 3-5 hours, so that the manganese nitrate is decomposed into manganese dioxide (MnO2) and firmly loaded on the surface of the activated carbon fiber, to obtain the precursor 1.

[0044] The catalyst for catalytic degradation of ozone in the application uses manganese dioxide, which has extremely high sensitivity to ozone at room temperature (10-30°C) and can quickly decompose ozone (the reaction rate constant can reach 0.1-0.5 s-1). Titanium dioxide is relatively sensitive to VOCs molecules, and the efficiency of catalytic degradation of VOCs molecules under the action of light reaches an average of 80-85%.

[0045] 4.2 Titanium dioxide (TiO2) and the precursor 1 are compounded

[0046] The precursor 1 is immersed in the prepared visible light-sensitive TiO2 sol. The TiO2 sol is fully penetrated into the pores of the activated carbon fiber and contacted with the loaded MnO2 by stirring at 50-70°C for 2-3 hours. After filtration, the sample is dried at 100-120°C for 6-8 hours and calcined at 300-400°C for 2-3 hours, so that the TiO2 is firmly loaded on the precursor 1.

[0047] The activated carbon fiber and the catalyst system particles are mixed in a certain proportion in the application, and the adsorption of the activated carbon fiber and the degradation of the catalyst system are combined to achieve the efficient degradation of ozone in the application.

[0048] When the mass ratio of the activated carbon fiber to manganese dioxide to modified titanium dioxide is 10:1:1, the removal efficiency of the material to ozone is the highest, reaching 90%. If the amount of the activated carbon fiber is increased and the amounts of MnO2 and TiO2 remain unchanged, the adsorption sites are increased, but the catalytic decomposition efficiency may be decreased, resulting in a decrease in the ozone removal rate.

[0049] If the amount of MnO2 is increased and the amounts of the activated carbon fiber and TiO2 remain unchanged, the decomposition efficiency of ozone is improved, but too much MnO2 may block the pores of the activated carbon fiber, affecting the adsorption capacity and leading to a decrease in the ozone removal rate.

[0050] If the amount of TiO2 is increased while the amounts of activated carbon fiber and MnO2 remain unchanged, the degradation efficiency of VOCs will increase and more adsorption sites will be released, but too much TiO2 may affect the catalytic action of MnO2, leading to a decrease in ozone removal rate.

[0051] If the amount of activated carbon fiber is too much and the amounts of MnO2 and TiO2 are insufficient, the adsorption capacity of ozone will increase, but the catalytic decomposition efficiency will decrease, and the ozone removal rate may decrease.

[0052] If the amount of MnO2 is too much and the amounts of activated carbon fiber and TiO2 are insufficient, the decomposition efficiency of ozone will increase, but the adsorption capacity will decrease, and the ozone removal rate may decrease.

[0053] If the amount of TiO2 is too much and the amounts of activated carbon fiber and MnO2 are insufficient, the degradation efficiency of VOCs will increase, but the catalytic action of MnO2 may be affected, and the ozone removal rate may decrease.

[0054] The activated carbon composite material loaded with MnO2 and TiO2 can still maintain high ozone removal efficiency after 100 hours of continuous operation, and the adsorption capacity of activated carbon only decreases by about 10%, which is significantly better than activated carbon without catalyst loading.

[0055] 5. Tabletting process

[0056] The activated carbon fiber loaded with catalyst can be pressed into tablets by the following steps:

[0057] Tabletting: Spread the activated carbon fiber loaded with catalyst evenly in the mold, apply a pressure of 10-20 MPa, and maintain for 5-10 minutes to form a tablet-shaped composite layer with a thickness of 0.5-1.0 mm.

[0058] 6. Post-treatment and performance optimization

[0059] Rinse the prepared modified activated carbon fiber with deionized water several times until no metal ions are detected in the rinse water (which can be detected by atomic absorption spectrometry). Dry again at 100-120°C for 6-8 hours.

[0060] Test the performance of the prepared material, including:

[0061] Specific surface area analysis (BET method): After loading the catalyst, the specific surface area remains at 800-1500 m 2 / g.

[0062] Ozone adsorption and decomposition performance test: The ozone removal rate can reach more than 80%.

[0063] VOCs degradation performance test: under visible light conditions, the degradation efficiency of formaldehyde can reach 70-85%, and the degradation efficiency of toluene is 50-65%.

[0064] Light transmittance test: the light transmittance (visible light band) of the fiber interwoven layer is 60-70%, indicating that it has moderate light transmittance and is suitable for photocatalytic reaction.

[0065] In the present application, the activated carbon fiber can maintain the ozone concentration in its pores at 9.8 mg / m 3 The optimal concentration of manganese dioxide catalytic degradation of ozone is 9.8 mg / m 3 The optimal concentration of manganese dioxide catalytic degradation of ozone is 9.8 mg / m 3 The optimal concentration of manganese dioxide catalytic degradation of ozone is 9.8 mg / m

[0066] Application of Example 2

[0067] The adsorption material prepared in the present application has a wide range of applications and can be used in various indoor places such as homes, offices, and schools, especially in places where there is a high risk of ozone pollution, such as electronic and electrical equipment workstations. For example, local personal protective equipment (such as purification devices) applied to workstations can remove ozone and achieve the function of oxygen bar.

[0068] Reference Figure 1 As shown in the figure, the structure of the purification device includes a shell, and a micro-pump design is provided at the air inlet and outlet, and a tablet (combination of activated carbon fiber and catalyst) and filter screen structure (wavy, honeycomb, etc.).

[0069] The shell is made of polypropylene (PP) material, which has good chemical corrosion resistance, heat resistance, and can maintain stability within a certain temperature range, is not easy to deform, and is non-toxic and odorless, meeting environmental protection requirements. Its shape can be designed as a cylinder according to the specific application scenario to provide protection and support for the internal purification components.

[0070] Air inlet and outlet: designed as bottom air inlet and top air outlet. The size of the air outlet is accurately calculated and optimized, and a micro air pump is provided in the air inlet of the shell. The air flow sucked in passes through the static pressure layer accurately, so that the entering air can be evenly dispersed to the inside of the device and fully contact with the activated carbon fiber and catalyst combination, maximizing the purification efficiency.

[0071] Filter screen and tablet: the activated carbon fiber and catalyst combination is tightly surrounded by a layer of high-precision filter screen, the filter screen aperture is determined to be between 3-8 microns according to actual requirements, which can effectively block impurities such as dust, pollen, particulate matter and the like from entering the inside of the device, preventing them from clogging the pores of the activated carbon fiber and catalyst. The activated carbon fiber loaded with catalyst is evenly spread in the mold, a pressure of 10-20 MPa is applied, and maintained for 5-10 minutes, forming a tablet-shaped composite layer with a thickness of 0.5-1.0 mm. The tablet-shaped composite layer is provided in multiple layers, stacked together, wrapped in the filter screen, and arranged on the gas outlet of the outer shell. After the gas passes through the filter screen, it enters the tablet-shaped composite layer area, ensuring that it is in full contact with the gas flow, playing a key role in adsorbing and catalytically decomposing ozone and other harmful gases, and is the core functional part of the entire device. The static pressure layer is in the outer shell, between the filter screen and the outlet of the micro air pump. In this way, the contact area and contact time of the gas with the activated carbon fiber and catalyst combination are effectively increased, while avoiding leakage of activated carbon fiber and catalyst particles, ensuring the stable operation of the purification device and the durability of the purification effect.

[0072] However, it should be noted that the ozone adsorption material needs to be replaced regularly (it is recommended to be replaced every 12 months), and maintaining a suitable temperature and humidity in the use environment (the optimal temperature is 10-30°C, and the relative humidity is 30-70%) is beneficial to increasing the service life of the material. The container is made of polypropylene or the like, and the inlet and outlet, the partition, the filter screen and the tablet structure are reasonably designed to ensure uniform airflow and prevent leakage, so as to ensure good purification effect.

[0073] Experimental data shows that under the condition that the initial concentration of ozone is 0.098-0.589 mg / m 3 , and the airflow velocity is 3-4 m / s, the ozone concentration can be reduced to a safe level (less than 0.16 mg / m 3 ) within 10-15 minutes, and the purification efficiency can still be maintained at more than 80% after 100 hours of continuous operation.

[0074] The above-described embodiments are only descriptions of preferred modes of the present application, and do not limit the scope of the present application. Without departing from the design spirit of the present application, various modifications and improvements to the technical solutions of the present application made by those of ordinary skill in the art should fall within the protection scope determined by the claims of the present application.

Claims

1. A method for preparing an indoor ozone-degrading material, characterized by: The method comprises the following steps: (1) loading manganese dioxide on the surface-activated active carbon fiber to obtain a precursor 1; (2) immersing the precursor 1 in a prepared visible light-sensitive TiO2 sol, and loading TiO2 on the precursor 1 through drying and calcination; The surface-activated active carbon fiber is prepared by placing the dried active carbon fiber in a mixed solution of sulfuric acid with a concentration of 1-3 mol / L and hydrogen peroxide with a volume fraction of 30%, and then performing ultrasonic treatment at 50-70 ℃ for 30-60 minutes, wherein the ultrasonic power is 200-400 W, and the volume ratio of the sulfuric acid to the hydrogen peroxide is 1:1-1:2; The visible light-sensitive TiO2 sol is prepared by mixing an organic dye, TiO2 and a carbon source, and the TiO2 is prepared by mixing tetrabutyl titanate and ethanol, adjusting the pH to 3-4, and stirring for 2 hours to form a transparent sol.

2. The method of claim 1, wherein: The specific surface area of the active carbon fiber is 500-1000 m² / g, and the fiber diameter is 8-12 μm.

3. The method of claim 2, wherein: The process of loading manganese dioxide on the active carbon fiber comprises the following steps: immersing the active carbon fiber in a manganese nitrate solution with a concentration of 0.3-0.6 mol / L, stirring at 40-60 ℃ for 2-4 hours, wherein the stirring speed is 300-500 rpm; filtering, drying at 100-120 ℃ for 6-10 hours, and then calcining at 350-500 ℃ for 3-5 hours.

4. The method of claim 1, wherein: The carbon source is urea or glucose, and the organic dye is phthalocyanine or porphyrin; the mass of the organic dye is 1%-2% of the mass of the TiO2, and the mass of the carbon source is the same as the mass of the TiO2.

5. The method of claim 1, wherein: In step (2), the precursor 1 is immersed in the visible light-sensitive TiO2 sol, stirred at 50-70 ℃ for 2-3 hours, filtered, dried at 100-120 ℃ for 6-8 hours, and then calcined at 300-400 ℃ for 2-3 hours.

6. An indoor ozone-degradation material prepared by the preparation method of any one of claims 1-5.

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