Filter component of a photocatalytic air purification device

Abstract

The present application relates to the field of air purification, and specifically provides a filtering component of a photocatalytic air purification device. The filtering component includes carbon dots, photocatalyst particles, an activated carbon layer, and a support portion. The carbon dots are fixedly arranged on the surface of the photocatalyst particles, the photocatalyst particles are fixedly arranged on one side of the activated carbon layer, the activated carbon layer is a porous structure, the support portion is a columnar shell with one end open, the bottom surface of the shell is a mesh structure, the activated carbon layer is fixedly arranged on the inner wall of the support portion, the activated carbon layer is fixedly adhesively connected to the inner wall of the support portion, and the bottom surface of the support portion contacts the side of the activated carbon layer away from the photocatalyst particles. In the filtering component of the present invention, the carbon dots and the activated carbon layer provided can reduce the recombination rate of photo-generated electrons and photo-generated holes inside the photocatalyst particles, improve the intensity of the photocatalytic reaction, and thus improve the purification efficiency. Therefore, the problem that the photo-generated electrons and photo-generated holes in the existing filtering component are prone to recombination and the air purification efficiency is low in the present invention is solved.

Description

Technical Field

[0001] The present application relates to the field of air purification, and more particularly, to a filtering component of a photocatalytic air purification device. Background Art

[0002] Carbon quantum dots, also known as carbon dots or carbon nanodots, are zero-dimensional carbon nanomaterials composed of quasi-spherical carbon nanoparticles. They have the advantages of wide raw material sources, simple preparation, low cost, low toxicity, and environmental friendliness. They have good electrical conductivity and can be used as electron acceptors.

[0003] The filtering component is the core part of a photocatalytic air purification device. The photocatalytic air purification device is used to purify particulate pollutants and gaseous pollutants in the air, such as dust, pollen particles, formaldehyde, etc. When in use, turn on the power of the photocatalytic air purification device, and the light source and the fan or air compressor start to work; the air to be purified enters the photocatalytic air purification device from the air inlet, and a photocatalytic reaction occurs at the filtering component inside the photocatalytic air purification device. Specifically, the photocatalyst particles are semiconductor materials. Under the illumination of the light source, the photocatalyst particles in the filtering component are in full contact with the air to be purified at the same time. When light irradiates on the photocatalyst particles, the energy of photons causes the electrons in the photocatalyst particles to transition from the valence band to the conduction band, thereby generating photo-generated electrons and photo-generated holes. The generated photo-generated electrons and photo-generated holes have strong redox capabilities. The photo-generated electrons with oxidation ability react with oxygen in the air to generate oxygen anions, and the photo-generated holes with reduction ability react with water molecules in the air to generate hydroxyl radical groups. The oxygen anions and hydroxyl radical groups have high activities and react with organic gas pollutants in the air to generate non-toxic carbon dioxide and water, completing the purification process; during the photocatalytic reaction process, the gaseous pollutants in the air to be purified are converted into non-toxic carbon dioxide and water, and finally discharged from the air outlet. After multiple cycles, the pollutants in the air will gradually decrease, and the air quality will get better and better, achieving the purpose of purifying the air. However, most of the electrons in the conduction band will return to the valence band and recombine with the holes, that is, the photo-generated electrons and photo-generated holes generated inside the photocatalyst particles recombine again, so that they cannot participate in the photocatalytic reaction, resulting in a weak photocatalytic reaction intensity and ultimately reducing the air purification efficiency of the photocatalytic air purification device.

[0004] In summary, due to the easy recombination of photo-generated electrons and photo-generated holes in the existing filtering component, the number of photo-generated electrons and photo-generated holes participating in the photocatalytic reaction is small, the photocatalytic reaction intensity is weak, and thus the air purification efficiency is low. Summary of the Invention

[0005] The object of the present invention is to provide a filtering component for a photocatalytic air purification device in view of the deficiencies in the above-mentioned prior art. The technical concept of the present invention is as follows: carbon dots have good conductivity and are disposed on the surface of photocatalyst particles, enabling some of the photo-generated electrons in the photocatalyst particles to migrate from the photocatalyst particles to the carbon dots, thereby preventing the recombination of this part of the photo-generated electrons with photo-generated holes, reducing the recombination rate of photo-generated electrons and photo-generated holes inside the photocatalyst particles, thus enhancing the intensity of the photocatalytic reaction and improving the purification efficiency. On the other hand, activated carbon also has conductivity, and a part of the photo-generated electrons in the photocatalyst particles will also migrate to the activated carbon layer, further reducing the recombination rate of photo-generated electrons and photo-generated holes in the photocatalyst particles, thereby enhancing the intensity of the photocatalytic reaction and further improving the air purification efficiency.

[0006] The technical solution disclosed by the present invention is as follows:

[0007] The present application provides a filtering component for a photocatalytic air purification device. The filtering component includes carbon dots, photocatalyst particles, an activated carbon layer, and a support portion. The carbon dots are a zero-dimensional carbon nanomaterial with a spherical shape. The photocatalyst particles are spherical photocatalytic materials, which are semiconductor materials with photocatalytic properties and can be one of TiO2, ZrO2, ZnO, CdS, WO3. The carbon dots are fixedly arranged on the surface of the photocatalyst particles, which can be fixedly connected by adhesion or by interaction forces. The particle size of the photocatalyst particles is greater than 150 nm. Preferably, the particle size of the photocatalyst particles is 500 nm - 50 μm, the particle size of the carbon dots is less than 8 nm, and the spacing between the carbon dots is 10 - 50 nm. In this way, a sufficient number of carbon dots can be arranged on the surface of the photocatalyst particles, and at the same time, the surface of the photocatalyst can be fully contacted with air and light. The activated carbon layer is an activated carbon bulk material or activated carbon cotton, and the activated carbon layer has a porous structure. The photocatalyst particles are fixedly arranged on one side of the activated carbon layer. The pore size of the side of the activated carbon layer is greater than half of the diameter of the photocatalyst particles and less than twice the diameter of the photocatalyst particles. Specifically, the photocatalyst particles do not completely block the openings, and the photocatalyst particles at the pore openings can be arranged at the edge of the pore wall or on the plane connecting the pores. In this way, the gas can flow through, and a large number of photocatalyst particles can be arranged. The photocatalyst particles can be multiple layers. Preferably, the number of layers of the photocatalyst particles is less than five layers, so that the airflow will not be blocked. When the number of layers is large, the air resistance is too large, making it difficult for the purified air to be discharged. The support portion is a columnar shell with one end open. The material of the support portion is an opaque hard material, such as cemented carbide, wood, etc. The bottom surface of the shell is a mesh structure, which can allow gas to flow through and can also support the activated carbon layer. The activated carbon layer is fixedly arranged on the inner wall of the support portion. The activated carbon layer is fixedly adhesively connected to the inner wall of the support portion. The bottom surface of the support portion contacts the side of the activated carbon layer away from the photocatalyst particles. Preferably, the mesh size of the mesh structure is less than 1.0 mm, which can also block a part of the large particle pollutants. The shape and size of the bottom surface of the support portion are the same as those of the plane of the bottom surface of the activated carbon layer in contact. In this way, it can not only protect the filter layer but also prevent the pollution of the activated carbon layer by larger particle pollutants. The height of the support portion needs to be at least 0.5 cm higher than the height of the filter layer inside the filtering component, which can play a role in protecting the internal filter layer.

[0008] The filter component of the present invention only needs to be placed at the filter layer position of the photocatalytic air purification device, and it is also convenient to replace. More specifically, the connection relationship between the filter component of the present invention and the photocatalytic device is related to the specific setting of the photocatalytic device. Specifically, the filter component of the present application can be adhesively fixed at the filter layer position inside the photocatalytic air purification device through the outer wall of the support part, or can be fixed through the matching card slot inside the air purifier. Optionally, threads can also be provided on the outer wall of the support part and fixedly connected through the matching threads inside the air purifier, that is, it is necessary to fix the filter component of the present invention at the position with a filter layer designed inside the photocatalytic air purification device. The light irradiates from the open side of the support part, and at the same time, air flows into the filter component of the present invention from the bottom of the support part of the present application. The purified air flows out from the open part of the support part and is finally discharged from the air outlet of the photocatalytic air purification device.

[0009] Furthermore, noble metal nanoparticles are also fixedly arranged on the surface of the photocatalyst particles. The material of the noble metal nanoparticles is gold or silver. The particle size of the noble metal nanoparticles is 20nm - 100nm. Such noble metal nanoparticles can generate local surface plasmon resonance effect under the action of light, resulting in the collective resonance of electrons on the surface of the noble metal nanoparticles and forming a strong electric field nearby. The noble metal nanoparticles do not contact the carbon dots, and the distance between the noble metal nanoparticles and the carbon dots is less than 150nm. In this way, the electric field intensity near the carbon dots is relatively strong, and the strong electric field will cause more photogenerated electrons in the photocatalyst particles to transfer to the carbon dots, thereby further reducing the recombination rate of photogenerated electrons and photogenerated holes in the photocatalyst particles and improving the purification efficiency. At the same time, the photogenerated electrons in the photocatalyst particles can migrate to the noble metal nanoparticles. On the one hand, it can reduce the recombination rate of photogenerated electrons and photogenerated holes in the photocatalyst particles. On the other hand, the electron concentration in the noble metal nanoparticles is higher, and the local surface plasmon resonance effect is stronger, making the electric field near the noble metal nanoparticles stronger, so that more photogenerated electrons in the photocatalyst particles transfer to the carbon dots, further reducing the recombination rate of photogenerated electrons - photogenerated holes in the photocatalyst particles, and thus further improving the purification efficiency. Furthermore, the surface of the photocatalyst particles is porous, and the depth and opening size of the pores are both 30nm - 10μm, and each photocatalyst particle has at least three pore structures.

[0010] Compared with the prior art, the beneficial effects of the present invention are as follows: Photocatalyst particles generate photogenerated electrons and photogenerated holes under the action of light. The carbon dots and activated carbon provided in the filter component of the present invention have conductivity, which can enable the generated photogenerated electrons to migrate from the photocatalyst particles to the carbon dots and activated carbon, thereby reducing the recombination rate of photogenerated electrons and photogenerated holes inside the photocatalyst particles, enhancing the intensity of the photocatalytic reaction, and further improving the purification efficiency. Description of the Drawings

[0011] Figure 1Schematic diagram of a filtering component of a photocatalytic air purification device provided by the present invention;

[0012] Figure 2 Schematic diagram of the principle of improving air purification efficiency in a filtering component of a photocatalytic air purification device provided by the present invention;

[0013] Figure 3 Schematic diagram of the bottom surface of a support part in a filtering component of a photocatalytic air purification device provided by the present invention;

[0014] Figure 4 TEM image of carbon dots prepared by the present invention;

[0015] Figure 5 UV absorption spectrum of carbon dots prepared by the present invention.

[0016] Icon: 1 - carbon dots; 2 - photocatalyst particles; 3 - activated carbon layer; 4 - support part. Detailed implementation manners

[0017] In order to make the implementation process of the present invention clearer, the following will be described in detail with reference to the accompanying drawings.

[0018] The present invention provides a filtering component of a photocatalytic air purification device. As Figure 1 shown, the filtering component includes carbon dots 1, photocatalyst particles 2, an activated carbon layer 3, and a support part 4. The carbon dots 1 are a kind of zero-dimensional carbon nanomaterial with a spherical shape. The photocatalyst particles 2 are spherical photocatalyst materials, which are semiconductor materials with photocatalytic properties and can be one of TiO2, ZrO2, ZnO, CdS, WO3, and have good electrical conductivity. The carbon dots 1 are fixedly arranged on the surface of the photocatalyst particles 2, which can be fixedly connected by adhesion or by mutual force. The particle size of the photocatalyst particles 2 is greater than 150 nm. Preferably, the particle size of the photocatalyst particles 2 is 500 nm - 50 μm. In this way, more carbon dots 1 can be arranged on the surface of the photocatalyst particles 2. The particle sizes of the photocatalyst particles 2 can be the same or different. Preferably, the particle sizes of the photocatalyst particles 2 are different, and the heights of the photocatalyst particles 2 are different. In this way, the light field can fully irradiate the surfaces of each photocatalyst particle 2, so that more photogenerated electrons and photogenerated holes are generated in the photocatalyst particles 2. The particle size of the carbon dots 1 is less than 8 nm, and the spacing of the carbon dots 1 is 10 nm - 50 nm. In this way, enough carbon dots can be arranged on the surface of the photocatalyst particles 2, and at the same time, the surface of the photocatalyst particles 2 can be fully contacted with air and light. The carbon dots 1 have electrical conductivity. As Figure 2As shown, the photo-generated electrons in the photocatalyst particles 2 can migrate to the carbon dots 1, generate hydroxyl radical groups with water molecules in the air on the surface of the carbon dots, and then react with organic gas pollutants, reducing the recombination rate of photo-generated electrons and photo-generated holes in the photocatalyst particles 2, increasing the intensity of the photocatalytic reaction, and improving the purification efficiency.

[0019] The carbon dots of the present invention can be prepared by the "top-down" method, such as arc discharge method, laser ablation method, etc., or by the "bottom-up" method, such as hydrothermal method, microwave method, pyrolysis method, etc. Specifically, the carbon dots are obtained by pyrolysis in this embodiment. More specifically, barley seedlings are used as the carbon source, the barley seedlings are cut into pieces and then ground into powder, deionized water is added for dissolution, ultrasonic treatment is carried out for 15 min, and then it is transferred to a crucible for pyrolysis. The temperature of the oven is 250 °C, and pyrolysis is carried out for 20 min. After natural cooling, it is taken out; then deionized water is added for high-speed centrifugation, the centrifugation speed is 10,000 rpm, the centrifugation time is 12 min, the supernatant is taken after centrifugation, and carbon dot powder is obtained by freeze-drying. Figure 4 To obtain the TEM image of the carbon dots, it shows that the size of the carbon dots obtained in this embodiment is 2 - 4 nm, and the lattice in the inset illustrates the formation of the carbon core. Figure 5 To obtain the UV absorption spectrum of the carbon dots, the absorption peak at 232 nm is caused by the π→π * transition of the C=C bond in the carbon dots, and the absorption peak at 296 nm is caused by the n→π * transition of the surface functional groups of the carbon dots, which indicates that the carbon dots are successfully prepared in this embodiment.

[0020] The activated carbon layer 3 is an activated carbon bulk material or activated carbon cotton, and the activated carbon layer 3 has a porous structure. The photocatalyst particles 2 are fixedly arranged on one side of the activated carbon layer 3, and the photocatalyst particles 2 are arranged on the entire side surface. The thickness of the activated carbon layer 3 is greater than 1.0 cm so as to effectively remove particulate pollutants in the air. The pore size of the orifice on this side of the activated carbon layer 3 is greater than half of the diameter of the photocatalyst particles 2 and less than twice the diameter of the photocatalyst particles 2. Specifically, the photocatalyst particles 2 do not completely block the opening, and the photocatalyst particles 2 at the orifice can be arranged at the edge of the pore wall or on the plane connecting the pores, so that both the gas flow can be realized and a relatively large number of photocatalyst particles 2 can be arranged. The photocatalyst particles 2 can be multiple layers. Preferably, the number of layers of the photocatalyst particles 2 is less than five layers, so as not to block the air flow. When the number of layers is large, the air resistance is too large, making it difficult for the purified air to be discharged. The support part 4 is a columnar shell with one end open, and the material of the support part 4 is an opaque hard material, such as cemented carbide, wood, etc. The bottom surface of the shell is in a Figure 3 mesh structure as shown, which can enable the gas to flow through and can also support the activated carbon layer 3. Specifically, the shape of the mesh holes can be circular or rectangular, and the arrangement of the mesh holes can be regularly arranged or irregularly arranged.

[0021] Furthermore, noble metal nanoparticles are fixedly arranged on the surface of the photocatalyst particles 2. The material of the noble metal nanoparticles is gold or silver. The particle size of the noble metal nanoparticles is 20nm - 100nm. Such noble metal nanoparticles can generate a strong local surface plasmon resonance effect under ultraviolet light illumination, resulting in the collective resonance of electrons on the surface of the noble metal nanoparticles and forming a strong electric field nearby. The noble metal nanoparticles do not contact the carbon dots 1, and the distance between the noble metal nanoparticles and the carbon dots 1 is less than 150nm. In this way, the electric field intensity near the carbon dots 1 is relatively strong, and the strong electric field will cause more photo-generated electrons in the photocatalyst particles 2 to transfer to the carbon dots 1, thereby further reducing the recombination rate of photo-generated electrons and photo-generated holes in the photocatalyst particles 2 and improving the purification efficiency. The distance between the noble metal nanoparticles is less than 300nm. In this way, a coupling phenomenon of local surface plasmon resonance can occur between adjacent noble metal nanoparticles, resulting in the generation of a strong electric field between adjacent noble metal nanoparticles and near the surface. The area of the strong electric field is larger, so that more carbon dots 1 are in the strong electric field, and more photo-generated electrons in the photocatalyst particles 2 transfer to the carbon dots 1, reducing the recombination rate of photo-generated electrons and photo-generated holes in the photocatalyst particles 2 and improving the purification efficiency. At the same time, the photo-generated electrons in the photocatalyst particles 2 can migrate into the noble metal nanoparticles. On the one hand, this can reduce the recombination rate of photo-generated electrons and photo-generated holes in the photocatalyst particles 2. On the other hand, the electron concentration in the noble metal nanoparticles is higher, and the local surface plasmon resonance effect is stronger, making the electric field near the noble metal nanoparticles stronger, so that more photo-generated electrons in the photocatalyst particles 2 transfer to the carbon dots 1, further reducing the recombination rate of photo-generated electrons - photo-generated holes in the photocatalyst particles 2, and thus further improving the purification efficiency.

[0022] Furthermore, the surface of the photocatalyst particles 2 is porous, with the depth of the pores being 50 nm - 10 μm and the opening size of the pores being 30 nm - 10 μm. Each photocatalyst particle 2 has at least three pore structures. Carbon dots 1 are fixedly arranged on the inner wall of the pores. On the one hand, more carbon dots 1 can be arranged on the photocatalyst particles 2 to accept more photogenerated electrons from the photocatalyst particles 2, further reducing the recombination rate of photogenerated electrons and photogenerated holes and improving the air purification efficiency. On the other hand, since the pore structure is closer to the core of the photocatalyst particles 2, the photogenerated electrons can migrate to the carbon dots 1 without moving to the surface, so that more photogenerated electrons can migrate from the photocatalyst particles 2 to the carbon dots 1, reducing the recombination rate of photogenerated electrons and photogenerated holes inside the photocatalyst particles 2 and improving the purification efficiency. On the further hand, the porous photocatalyst particles 2 increase the surface area, making the interaction between the photocatalyst particles 2, the light field, and the air more sufficient. That is, more photogenerated electrons and photogenerated holes can be generated under the irradiation of the light field. At the same time, there are more active sites on the surface of the photocatalyst particles 2, and more substances such as oxygen and water molecules required for the surrounding photocatalytic reaction, making the photocatalytic reaction proceed more fully, so the intensity of the photocatalytic reaction is greater, that is, the air purification efficiency is higher.

[0023] Noble metal nanoparticles are also fixedly arranged at the openings of the pore structures. Preferably, the particle size of the noble metal nanoparticles is 20 nm - 100 nm. When the size of the noble metal nanoparticles at the openings is 20 nm - 30 nm, they can be arranged on the inner wall of the pores. When the particle size is greater than 30 nm, they are arranged at the edge of the openings. It should be noted that the noble metal nanoparticles do not completely block the openings of the pore structures so that light and air can enter the pore structures. In this way, the photogenerated electrons on the carbon dots 1 can interact with the air under the action of light to carry out photocatalytic reactions, thereby improving the purification efficiency. Under the irradiation of the light field, the noble metal nanoparticles generate local surface plasmon resonance, and a strong electric field is generated on the surface of the noble metal nanoparticles. The generated strong electric field is localized in the pore structures, making the intensity of the local electric field stronger. Thus, the electric field intensity around the carbon dots 1 inside the pore structures is stronger. The strong electric field makes more photogenerated electrons migrate from the photocatalyst particles 2 to the carbon dots 1, reducing the recombination rate of photogenerated electrons and photogenerated holes in the photocatalyst particles 2. There is sufficient air and light in the pores, and more photogenerated electrons participate in the photocatalytic reaction on the surface of the carbon dots 1. Therefore, the noble metal nanoparticles at the openings of the pore structures further reduce the recombination rate of photogenerated electrons and photogenerated holes in the photocatalyst particles 2, further enhance the intensity of the photocatalytic reaction, and further improve the air purification efficiency. The porous photocatalyst particles 2 can be prepared by one of corrosion, electron beam lithography, hydrothermal method, and sol-gel method.

[0024] During application, the filtration component of the present invention needs to be fixed at the position with a filtration layer designed inside the photocatalytic air purification device. The light irradiates from the open side of the support part. At the same time, air flows into the filtration component of the present invention from the bottom of the support part of the present application, and the purified air flows out from the open side of the support part and is finally discharged from the air outlet of the photocatalytic air purification device. In the present invention, the specific shape of the cross-section in the direction perpendicular to the axis of the activated carbon layer 3 can be circular, rectangular, etc., and its shape needs to be consistent with the shape of the filtration layer provided in the photocatalytic air purification device. The air to be purified flows in from the side of the activated carbon layer 3 far from the photocatalyst particles 2, that is, from the bottom of the support part 4, and flows out from the side of the activated carbon layer 3 close to the photocatalyst particles 2. The light source is an ultraviolet light source or an ultraviolet-visible light source. The light emitted by the light source irradiates on the surface of the photocatalyst particles 2, that is, the light irradiates from the side of the activated carbon layer 3 provided with the photocatalyst particles 2. The energy of the photons causes the electrons in the valence band of the photocatalyst material to transition to the conduction band, generating photo-generated electrons in the conduction band and photo-generated holes in the valence band. The generated photo-generated electrons and photo-generated holes have strong oxidation-reduction capabilities. The photo-generated electrons with oxidation ability react with oxygen in the air to generate oxygen anions, and the photo-generated holes with reduction ability react with water molecules in the air to generate hydroxyl radical groups. The oxygen anions and hydroxyl radical groups have high activities and react with organic gas pollutants in the air to generate non-toxic carbon dioxide and water, completing the purification process. The purified air is finally discharged from the air outlet. The presence of the carbon dots 1 causes the photo-generated electrons to migrate from the photocatalyst particles 2 to the carbon dots 1, making it difficult for the photo-generated electrons and photo-generated holes in the photocatalyst particles 2 to recombine, thereby enhancing the intensity of the photocatalytic reaction and improving the air purification efficiency. In addition, under the action of light irradiation, a local surface plasmon resonance effect is generated on the surface of the noble metal nanoparticles, generating a strong electric field on its surface. The existence of the strong electric field enables the carbon dots 1 in the strong electric field to obtain more electrons from the photocatalyst particles 2, that is, the recombination rate of the photo-generated electrons and photo-generated holes in the photocatalyst particles 2 is further reduced, thereby further improving the air purification efficiency. Therefore, the air purification efficiency of the filtration component of the present invention is relatively high.

[0025] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A filtering component of a photocatalytic air purification device, characterized in that, The filtering component includes carbon dots, photocatalyst particles, an activated carbon layer, and a support portion. The carbon dots are fixedly arranged on the surface of the photocatalyst particles. Noble metal nanoparticles are arranged on the surface of the photocatalyst particles, and there is no contact between the noble metal nanoparticles and the carbon dots. The photocatalyst particles are fixedly arranged on one side of the activated carbon layer. The activated carbon layer is a porous structure. The support portion is a columnar shell with one end open, and the bottom surface of the shell is a mesh structure. The activated carbon layer is fixedly arranged on the inner wall of the support portion, and the activated carbon layer is fixedly adhesively connected to the inner wall of the support portion. The bottom surface of the support portion contacts the side of the activated carbon layer away from the photocatalyst particles. The surface of the photocatalyst particles is porous, and the carbon dots are fixedly arranged on the inner wall of the pores. The particle size of the carbon dots is less than 8 nm, the particle size of the photocatalyst particles is greater than 150 nm, the depth and opening size of the pores on the surface of the photocatalyst particles are 30 nm - 10 μm, and the particle size of the noble metal nanoparticles is 20 nm - 100 nm.

2. The filtering component of the photocatalytic air purification device according to claim 1, wherein The material of the noble metal nanoparticles is gold or silver.

3. The filtering component of the photocatalytic air purification device according to claim 1, characterized in that, The porous structure on the activated carbon layer is pores in the micro-nano scale.

4. The filter component of the photocatalytic air purification device according to claim 3, characterized in that The activated carbon layer is made of activated carbon bulk material or activated carbon cotton.

5. The filter component of the photocatalytic air purification device according to claim 4, characterized in that, The material of the photocatalyst particles is one of TiO2, ZrO2, ZnO, CdS, WO3.

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