Flexible electronic fabric of interdigital electrode structure for degrading volatile organic pollutants on basis of photoelectrocatalysis, preparation method therefor and use thereof

Abstract

A flexible electronic fabric of an interdigital electrode structure for degrading volatile organic pollutants on the basis of photoelectrocatalysis, a preparation method therefor and a use thereof, relating to the technical field of flexible electronic fabrics having a photoelectrocatalytic function. The flexible electronic fabric comprises a bottom filter screen layer, an interdigital electrode layer embroidered on a filter screen, a photocatalytic material layer attached to the top of the interdigital electrode layer, an external direct-current power source for supplying power, and an external light source for providing illumination; positive and negative electrodes of the external direct-current power source are connected to two ends of the interdigital electrode layer by means of alligator clips to supply power to provide electrocatalytic conditions. The functional flexible electronic fabric can be embroidered in different specifications and sizes on the basis of the actual space area of a house in an indoor environment, or a plurality of identical flexible electronic fabrics can be simultaneously placed for degradation of volatile organic pollutants. Additionally, large-scale automatic production can be achieved by means of an embroidery machine, and functional flexible electronic fabrics having a photoelectrocatalytic function can be mass-produced from a photocatalytic material by means of simple coating and drying.

Description

A flexible electronic fabric with an interdigitated electrode structure based on photoelectrocatalytic degradation of volatile organic pollutants and its preparation method and application Technical Field

[0001] The present invention relates to the technical field of flexible electronic fabrics with photoelectrocatalytic functions, and in particular to a flexible electronic fabric with an interdigitated electrode structure based on photoelectrocatalytic degradation of volatile organic pollutants, as well as a preparation method and application thereof. Background Art

[0002] Urbanization and industrialization have led to a rapid increase in volatile organic compound emissions, posing a serious threat to the ecological environment and human health. The second half of the 19th century and throughout the 20th century saw an intensification of industrial activity and rapid advancements in science and technology. However, this growth also brought pollution, causing severe damage to the atmosphere, water resources, and soil.

[0003] In order to maximize the improvement of air quality, more and more researchers are studying strategies to eliminate volatile organic compounds in the atmosphere. Currently, in order to achieve the goal of removing volatile organic pollutants from the atmosphere, researchers have invented physical technologies based on adsorption, condensation, and membrane separation, chemical methods such as combustion and plasma technology, and biodegradation technology. Most of these methods have defects such as secondary pollution, complex operation, expensive equipment, and susceptibility to environmental factors, which seriously limit their application in daily life. Compared with these technologies, catalytic oxidation has low energy consumption, is convenient and easy to use, and can completely oxidize volatile organic pollutants into non-toxic and harmless water and carbon dioxide at room temperature with the help of photocatalysts to produce a catalytic reaction, achieving a harmless treatment effect.

[0004] Current research shows that when using semiconductor photocatalysts as photocatalytic materials, although the photocatalytic efficiency can be improved by loading precious metals and transition metals, the photogenerated electron-hole pairs in the semiconductor material are very easy to recombine, resulting in a significant reduction in the efficiency of degrading volatile organic pollutants. Therefore, additional electrocatalysis can be used to assist photocatalysis to reduce the impact of this defect and thus improve the removal efficiency of volatile organic pollutants. Currently, almost all the principle structures proposed for the degradation of volatile organic pollutants are too complex to be designed for large-scale manufacturing processes. Therefore, it is particularly important to design a device structure with photoelectrocatalytic degradation of volatile organic pollutants that can be produced through automated mass production.

[0005] Summary of the Invention

[0006] Technical problem to be solved: In response to the problems existing in the prior art, the present invention provides a flexible electronic fabric with an interdigitated electrode structure based on photoelectrocatalytic degradation of volatile organic pollutants, as well as a preparation method and application. In an indoor environment, the functional flexible electronic fabric can be embroidered with different specifications and sizes according to the actual space area of ​​the house, or multiple identical flexible electronic fabrics can be placed at the same time for the degradation of volatile organic pollutants.

[0007] Technical solution: A flexible electronic fabric with an interdigital electrode structure based on photoelectrocatalytic degradation of volatile organic pollutants, including a bottom filter layer, an interdigital electrode layer embroidered on the filter, and a photocatalytic material layer attached to the top of the interdigital electrode layer, as well as an external DC power supply for power supply and an external light source for providing illumination. The positive and negative poles of the external DC power supply are connected to the two ends of the interdigital electrode layer through alligator clips to provide power and electrocatalytic conditions. The external light source is placed above the attached photocatalytic material layer to illuminate the fabric and provide photocatalytic conditions.

[0008] Preferably, the filter mesh layer is a nylon mesh, a gauze cloth or a screen filter cloth, and the gap size of the filter mesh is 10 to 400 meshes, and has insulation and good air permeability.

[0009] Preferably, the interdigital electrode layer is embroidered with conductive fibers having excellent conductivity, and the conductive fibers include metal fibers, carbon black fibers, conductive metal compound fibers, or conductive polymer fibers, such as silver fibers, 316L stainless steel fibers, copper fibers, carbon fibers, and the like.

[0010] Furthermore, the electrical resistance per centimeter of a single conductive fiber is between 0.1Ω and 1kΩ.

[0011] Furthermore, the shape, length, width, number of fingers and distance between the interdigital electrodes in the interdigital electrode layer can be selected according to actual needs. There is no limit on the length, width and number of fingers of the interdigital electrodes, and they can be adjusted within the minimum to maximum range that the embroidery machine can embroider.

[0012] Preferably, the distance between the interdigital electrodes is 3 to 7 mm.

[0013] Preferably, the photocatalytic material in the photocatalytic material layer is a photocatalyst material, such as TiO2, ZrO2, ZnO, CdS, WO3, Fe2O3, PbS, SnO2, ZnS, SrTiO3, SiO2, g-C3N4, etc., or a loaded noble metal photocatalyst, such as Pt, Pd, Au, Ag, etc.

[0014] Preferably, the photocatalytic material in the photocatalytic material layer is a mixture of a photocatalytic material and a polyurethane adhesive material, which can better enable the photocatalytic material to adhere to the filter embroidered with interdigital electrodes. The mixing ratio can be selected according to the firmness of adhesion.

[0015] Preferably, the mass percentage of the polyurethane adhesive material is 1 wt% to 10 wt%.

[0016] A method for preparing a flexible electronic fabric with an interdigitated electrode structure for photoelectrocatalytic degradation of volatile organic pollutants, based on the aforementioned method, comprises the following steps: embroidering an interdigitated electrode layer on a filter layer, then spraying or dipping the interdigitated electrode layer with a photocatalytic material layer, then connecting an external DC power supply to both ends of the interdigitated electrode layer via alligator clips, and placing a UV or visible light source above the coated photocatalytic material layer. The number of spraying or dipping operations can be selected based on the desired amount of photocatalytic material to be attached. The voltage applied by the external DC power supply to the interdigitated electrodes is adjusted based on the selected photocatalytic material. The output power of the light source and the distance from the fabric can also be adjusted based on the properties of the photocatalytic material.

[0017] Preferably, the spraying or dipping is performed 1 to 5 times.

[0018] Preferably, the voltage is 5 to 35V.

[0019] Based on the above-mentioned application of the flexible electronic fabric with an interdigitated electrode structure based on photoelectrocatalytic degradation of volatile organic pollutants in the photocatalytic degradation of volatile organic pollutants, the volatile organic pollutants include formaldehyde, toluene, ammonia, nitric oxide, nitrogen-containing gas exhaust, sulfur-containing waste gas pollutants, carbon oxides or organic hydrocarbon waste pollutants.

[0020] Preferably, the concentration of the volatile organic pollutants is 5 to 40 ppm.

[0021] Based on the above application of the flexible electronic fabric with interdigitated electrode structure for photoelectrocatalytic degradation of volatile organic pollutants in the degradation of bioaerosols, the bioaerosols are microbial aerosols, and the microbial aerosols are bacteria, fungi or viruses.

[0022] The forming principle of the present invention is as follows: the present invention adopts a filter screen with a mesh size of 10 to 400 as the bottom fabric to be embroidered, and adopts conductive fibers with excellent conductive properties for embroidery, with a single-filament resistance of 0.1 Ω to 1 kΩ per centimeter; an embroidery machine is used to embroider the conductive fibers on the bottom filter screen to form an interdigital electrode structure, and the shape, length, width, number of interdigital fingers and the distance between the interdigital electrodes can be selected according to actual needs; a photocatalytic material or a photocatalytic material mixed with a polyurethane adhesive is sprayed onto the surface of the nylon mesh embroidered with the interdigital electrode structure by a spray gun, or the filter screen embroidered with the interdigital electrode structure can be dipped into the filter screen. Soaked in a photocatalytic material solution of a catalyst material or a mixed polyurethane adhesive, the number of spraying and soaking times can be selected according to the required loaded photocatalytic material content. It should be noted that before the next spraying or soaking of the photocatalytic material, the photocatalytic material sprayed or soaked last time must be completely dry to prevent the fabric surface from being in a saturated state, resulting in repeated spraying or dipping without achieving a cumulative coating effect; the positive and negative poles of the external DC power supply are directly applied to the two ends of the fabric embroidered with interdigital electrodes, and the DC power switch and the external light source switch are turned on at the same time, so that the photoelectric catalytic effect can synergistically degrade volatile organic pollutants.

[0023] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages:

[0024] (1) The present invention is based on an interdigitated electrode fabric embroidered on a filter screen, and can achieve the purpose of degrading volatile organic pollutants by coating different photocatalytic materials and applying additional voltage and light to the prepared fabric simultaneously;

[0025] (2) The present invention provides a method for preparing flexible electronic fabrics with photoelectrocatalytic degradation of volatile organic pollutants suitable for large-scale, automated production. Flexible electronic fabrics with interdigital electrode structures of different sizes can be produced according to the minimum to maximum embroidery size of an embroidery machine to achieve the purpose of degrading volatile organic pollutants of different concentrations. In addition, multiple pieces of the same flexible electronic fabrics can be placed simultaneously to achieve the purpose of rapidly degrading volatile organic pollutants, which has important practicality.

[0026] (3) The flexible electronic fabric for photoelectrocatalytic degradation of volatile organic pollutants of the present invention has low production cost and simple operation. The fabric with interdigital electrodes coated with photocatalytic materials can also degrade volatile organic pollutants by simply using electrocatalysis or photocatalysis, and has broad application prospects.

[0027] BRIEF DESCRIPTION OF THE DRAWINGS

[0028] FIG1 is a schematic diagram of a flexible electronic fabric embroidered with different interdigital electrode structures according to the present invention, wherein (a) is an embroidered linear interdigital electrode structure; (b) is an embroidered wavy interdigital electrode structure;

[0029] FIG2 is a schematic diagram showing the principle of degradation of volatile organic pollutants by a flexible electronic fabric with an embroidered linear interdigitated electrode structure coated with a photocatalytic layer;

[0030] Figure 3 shows a linear interdigitated electrode structure embroidered with 316L stainless steel fibers, which is actually processed into a flexible electronic fabric structure with interdigitated electrodes of different spacings: (a) electrode spacing d = 3 mm, (b) electrode spacing d = 5 mm, and (c) electrode spacing d = 7 mm.

[0031] FIG4 is a graph showing (a) ultraviolet absorption spectra and (b) fluorescence spectra of polyurethane mixed photocatalytic materials with different concentrations;

[0032] FIG5 is a graph showing the time-dependent photoelectrocatalytic degradation of 40 ppm formaldehyde at different voltages by embroidering linear interdigitated electrodes with spacings of (a) 3 mm, (b) 5 mm, and (c) 7 mm, coated three times with photocatalytic layers;

[0033] FIG6 shows the removal efficiency of 40 ppm of photocatalytic degradation by applying a voltage of 30 V for 3 hours on a linear interdigitated electrode structure with an embroidered electrode spacing of 5 mm and coated with different numbers of photocatalytic material layers on top;

[0034] Figure 7 shows the time required for photoelectrocatalytic complete degradation of formaldehyde at different concentrations by applying a voltage of 30V when the embroidered linear interdigitated electrode structure with an electrode spacing of 5 mm is coated with three photocatalytic layers.

[0035] DETAILED DESCRIPTION

[0036] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0037] Example 1

[0038] The present embodiment provides a flexible electronic fabric with an interdigitated electrode structure for photoelectrocatalytic degradation of volatile organic pollutants, comprising a bottom filter layer, an interdigitated electrode layer embroidered on the filter, and a photocatalytic material layer attached to the top of the interdigitated electrode layer, as well as an external DC power supply for powering and an external light source for providing illumination. The positive and negative electrodes of the external DC power supply are connected to the two ends of the interdigitated electrode layer via alligator clips to provide power and electrocatalytic conditions, and the external light source is placed above the attached photocatalytic material layer to illuminate the fabric and provide photocatalytic conditions, as shown in FIG2 .

[0039] The specific preparation process is as follows:

[0040] (1) A nylon mesh with a mesh size of 60 mesh and a length and width of 20cm*20cm was selected as the bottom embroidery layer, and 316L stainless steel fiber with a centimeter resistance of 0.9Ω was embroidered into a flexible electronic fabric in the form of a forked electrode. First, a linear forked electrode structure embroidery layout was generated using the Wilcom program, as shown in FIG1(a) (it can also be replaced with a wavy forked electrode structure, as shown in FIG1(b)), and imported into the embroidery machine through a flash drive. Then, the 316L SSF was inserted into the embroidery machine and the bottom fabric to be embroidered was placed at the embroidery needle. Finally, the machine was started for embroidery operation. The distance between the embroidered forked electrodes was 5mm for degrading 40ppm formaldehyde, as shown in FIG3(b);

[0041] (2) 1 wt% platinum-loaded titanium dioxide was selected as the photocatalyst material, and 5 wt% polyurethane was added to the 1 wt% platinum-loaded titanium dioxide solution as an adhesive. The polyurethane was completely dispersed in the titanium dioxide solution by ultrasonic vibration for ten minutes;

[0042] (3) Pour the prepared mixed solution into the spray bottle of a spray gun with a mouth diameter of 0.6mm. It should be noted that the two ends of the flexible electronic fabric connected to the DC power supply cannot be sprayed with the titanium dioxide mixed solution, otherwise it will affect the conductivity and thus reduce the photoelectrocatalytic effect. You can directly wrap the two ends of the embroidered interdigital electrodes with tin foil. Finally, turn on the spray gun and spray from top to bottom until the fabric surface is completely wetted, and move it to an 80℃ oven for about 20 minutes to ensure that the surface of the flexible electronic fabric is dry. The above spraying-drying operation can be repeated to increase the amount of photocatalytic material attached to the surface of the interdigital electrode. Here, a flexible electronic fabric with an interdigital electrode structure based on photoelectrocatalytic degradation of volatile organic pollutants was prepared by repeating the spraying three times.

[0043] (4) Here, a polyurethane adhesive material (PU) with a concentration of 0 to 10 wt% can be added to the 1 wt% metal platinum-loaded titanium dioxide solution in step (2). The absorbance and intensity of the mixed photocatalytic solution measured by ultraviolet spectrometer and fluorescence spectrophotometer are shown in Figures 4(a) and 4(b), respectively. It can be seen that as the concentration of polyurethane increases, the overall performance of the photocatalytic material decreases. As a preferred embodiment, combined with the auxiliary effect of electrocatalysis in practice, the subsequent embodiments all use a polyurethane concentration of 5 wt% as the most suitable adhesion material addition concentration.

[0044] Example 2

[0045] Same as Example 1, except that a 60-mesh screen is selected as the bottom embroidery layer in step (1).

[0046] Example 3

[0047] The same as Example 1, except that in step (1), an 80-mesh nylon mesh is selected as the bottom embroidery layer.

[0048] Example 4

[0049] The same as Example 1, except that in step (1), carbon fiber is selected as the conductive fiber for embroidery.

[0050] Example 5

[0051] The same as Example 1, except that the overall size of the interdigital electrodes embroidered in step (1) is 20 cm*20 cm, and the distance between the electrodes is 3 mm, as shown in Figure 3(a).

[0052] Example 6

[0053] The same as Example 1, except that the overall size of the interdigital electrodes embroidered in step (1) is 20 cm*20 cm, and the distance between the electrodes is 7 mm, as shown in Figure 3(c).

[0054] The products prepared in Examples 1, 5 and 6, which were embroidered into straight interdigitated electrodes with spacings of 3 mm, 5 mm and 7 mm and coated with a photocatalytic layer three times, were tested for performance of photoelectrocatalytic degradation of 40 ppm formaldehyde at different voltages over time. As shown in Figures 5 (ac), it can be seen that within the same time range, the external applied voltage required to achieve the highest degradation efficiency at different electrode spacings is different. Preferably, the voltage can be reasonably selected according to the embroidery electrode spacing.

[0055] Example 7

[0056] The same as Example 1, except that the overall size of the interdigital electrodes embroidered in step (1) is 40 cm*40 cm, and the number of interdigital electrodes can be increased proportionally.

[0057] Example 8

[0058] Same as Example 1, except that g-C3N4 is selected as the photocatalyst material in step (2).

[0059] Example 9

[0060] The same as Example 1, except that in step (3), the photocatalytic material is coated on the flexible electronic fabric embroidered with interdigitated electrodes by dipping, and the end of the flexible electronic fabric connected to the DC power supply cannot be dipped into the titanium dioxide mixed solution, otherwise it will affect the conductivity and thus reduce the photoelectrocatalytic effect. The two ends of the flexible electronic fabric embroidered with interdigitated electrodes can be directly slightly raised to expose the liquid surface, and the dipping is repeated 3 times.

[0061] Example 10

[0062] The same as Example 1, except that the number of spraying times in step (3) is 1 time, and can also be 2 times, 4 times, or 5 times.

[0063] The photocatalytic material layer coated different times on the top of the embroidered linear interdigitated electrode structure with an electrode spacing of 5 mm prepared in Example 1 and Example 10 was subjected to a performance test on the removal efficiency of 40 ppm of photoelectrocatalytic degradation by applying a voltage of 30 V within 3 hours. As shown in Figure 6, it can be seen that too few or too many coating times cannot achieve the optimal degradation effect. Preferably, the photocatalytic material is coated 3 times.

[0064] Example 11

[0065] The same as Example 1, except that the formaldehyde of different concentrations is degraded in step (1), ranging from 5 to 40 ppm.

[0066] The time required for photoelectrocatalytic complete degradation of formaldehyde at different concentrations by applying a voltage of 30 V to the linear interdigitated electrode structure with an electrode spacing of 5 mm embroidered in Example 1 after coating three photocatalytic layers is shown in FIG7 . It can be seen that as the concentration increases, the time required for complete degradation of formaldehyde also increases.

Claims

1. A flexible electronic fabric with an interdigitated electrode structure based on photoelectrocatalytic degradation of volatile organic pollutants, characterized in that: It includes a bottom filter layer, an interdigital electrode layer embroidered on the filter, a photocatalytic material layer attached to the top of the interdigital electrode layer, an external DC power supply for powering and an external light source for providing illumination, wherein the positive and negative poles of the external DC power supply are connected to both ends of the interdigital electrode layer through crocodile clips, and the external light source is placed above the attached photocatalytic material layer.

2. The flexible electronic fabric with interdigital electrode structure based on photoelectrocatalytic degradation of volatile organic pollutants according to claim 1, characterized in that: The filter screen layer is a nylon mesh, a gauze cloth or a screen filter cloth, the gap size of the filter screen is 10-400 meshes, and has insulation and air permeability.

3. The flexible electronic fabric with interdigital electrode structure based on photoelectrocatalytic degradation of volatile organic pollutants according to claim 1, characterized in that: The interdigital electrode layer is embroidered with conductive fibers having excellent conductivity, and the conductive fibers include metal fibers, carbon black fibers, conductive metal compound fibers or conductive polymer fibers.

4. The flexible electronic fabric with interdigital electrode structure based on photoelectrocatalytic degradation of volatile organic pollutants according to claim 3, characterized in that: The distance between the interdigital electrodes is 3-7 mm.

5. The flexible electronic fabric with interdigital electrode structure based on photoelectrocatalytic degradation of volatile organic pollutants according to claim 1, characterized in that: The photocatalytic material in the photocatalytic material layer is a photocatalyst material.

6. The flexible electronic fabric with interdigital electrode structure based on photoelectrocatalytic degradation of volatile organic pollutants according to claim 5, characterized in that: The photocatalytic material in the photocatalytic material layer is a mixture of a photocatalyst material and a polyurethane adhesive material.

7. A method for preparing a flexible electronic fabric with an interdigitated electrode structure based on photoelectrocatalytic degradation of volatile organic pollutants according to claim 1, characterized in that: The steps are as follows: embroider a forked electrode layer on the filter layer, then spray or dip-coat the photocatalytic material layer on the forked electrode layer, then connect an external DC power supply to both ends of the forked electrode layer through an alligator clip, use ultraviolet light or visible light as an external light source, and place it above the coated photocatalytic material layer.

8. The use of the flexible electronic fabric with interdigital electrode structure based on photoelectrocatalytic degradation of volatile organic pollutants according to claim 1 in photocatalytic degradation of volatile organic pollutants, characterized in that: The volatile organic pollutants include formaldehyde, toluene, ammonia, nitric oxide, nitrogen-containing gas waste gas, sulfur-containing waste gas pollutants, carbon oxides or organic hydrocarbon waste pollutants.

9. The use of the flexible electronic fabric with interdigital electrode structure based on photoelectrocatalytic degradation of volatile organic pollutants according to claim 1 in photocatalytic degradation of volatile organic pollutants, characterized in that: The concentration of the volatile organic pollutants is 5 to 40 ppm.

10. The use of a flexible electronic fabric with an interdigitated electrode structure based on photoelectrocatalytic degradation of volatile organic pollutants according to claim 1 in the degradation of bioaerosols, characterized in that: The bioaerosol is a microbial aerosol, and the microbial aerosol is bacteria, fungi or viruses.

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