Photocatalytic fiber fabric, preparation method and application thereof

Abstract

The present invention discloses a photocatalytic fiber fabric, a preparation method and an application thereof, and belongs to the field of photocatalytic technology. The photocatalytic fiber fabric is prepared by the following method: a fiber fabric containing carboxylic acid group, amine group and hydroxyl functional group is prepared by chemical grafting method; photocatalyst powder A is prepared by hydrothermal method using sodium bismuthate, metal salt and polyvinyl alcohol as raw materials, photocatalyst powder B is prepared by anoxic pyrolysis method using at least one of urea, melamine and melamine as raw materials, and a mixed dispersion of photocatalyst powder A and photocatalyst B is prepared by ultrasonic dispersion method; the photocatalyst dispersion is evenly coated on the surface of the fiber fabric to obtain the photocatalytic fiber fabric. The present invention is simple to operate, green and environmentally friendly, suitable for industrial production and use, and the prepared photocatalytic fiber fabric can achieve the dual effects of pollutant purification and antibacterial sterilization in the environment under the drive of ultra-low power LED white light.

Description

Technical Field

[0001] The present invention belongs to the technical field of photocatalytic environmental purification, and specifically relates to a photocatalytic fiber fabric, a preparation method and an application thereof in realizing photocatalytic antibacterial and environmental purification under the driving of LED white light. Background Art

[0002] Sunlight-driven photocatalysis has the advantages of low cost, high efficiency, and environmental friendliness, and has gradually been widely studied in the fields of environmental purification and antibacterial sterilization. Designing a photocatalyst with a suitable energy band structure is a key factor in determining the efficiency of photocatalysis. Existing photocatalysts such as TiO2, ZnO, and g-C3N4 usually have problems such as difficulty in effectively utilizing sunlight (especially visible light and infrared light, which account for more than 90%), easy occurrence of hole-electron pair recombination, and poor photocatalytic performance. Constructing oxygen vacancies and heterogeneous structures is considered to be the main means to improve photocatalytic performance. In recent years, photocatalysts with abundant oxygen vacancies and the coexistence of multivalent ions (Bi 3+ and Bi 5+ ) has aroused great interest among researchers. This type of photocatalyst has significant advantages such as abundant bismuth reserves, non-toxicity, multiphase structure, narrow band gap (<2eV) and absorption of the entire solar spectrum. The oxygen vacancies in the structure of bismuth oxides are mainly introduced by the hydrothermal reaction of sodium bismuthate in aqueous sodium hydroxide solution, which usually requires high temperature (>180℃) and long reaction time (>12 hours). By adjusting the hydrothermal reaction conditions (such as hydrothermal temperature, sodium hydroxide concentration, reaction time), it is helpful to form a variety of bismuth oxides (such as BiO 2-x 、Bi2O4、Bi4O7、Bi2O 2.75 However, the photocatalytic performance of these photocatalysts still cannot meet practical needs, especially under the illumination of ultra-low-power LEDs that can be found everywhere, it is difficult to play the role of photocatalytic antibacterial and environmental purification.

[0003] In practical applications, powder photocatalysts have defects such as easy agglomeration, difficult separation, and easy to cause secondary pollution. Introducing powder photocatalysts into fiber fabric structures to produce photocatalytic fiber fabrics is one of the effective measures to solve the defects of powder photocatalysts. Usually, photocatalyst powders are bonded to the base fiber fabric using a binder to form a photocatalyst coating, or photocatalyst powders are dispersed in a polymer spinning solution for spinning to obtain photocatalytic fiber fabrics. However, the former has problems such as uneven loading, easy detachment of the coating, and the influence of the binder on the photocatalytic activity. The latter has problems such as the need for complex spinning equipment and the easy encapsulation or covering of the photocatalytic active sites by the polymer. Summary of the invention

[0004] In view of the above-mentioned defects, the purpose of the present invention is to provide a photocatalytic fiber fabric, a preparation method and its application in realizing catalytic antibacterial and environmental purification under the driving of LED white light, aiming to solve the technical problem that conventional photocatalysts are difficult to play antibacterial and environmental purification roles under ultra-low power LED white light, and at the same time solve the technical problem that powder photocatalysts are difficult to stably load on the surface of fiber fabrics and efficiently play a photocatalytic role. The preparation method provided by the present invention is simple to operate, green and environmentally friendly, suitable for industrial production, and the prepared photocatalytic fiber fabric can achieve the dual effects of pollutant purification and antibacterial sterilization in the environment under the driving of ultra-low power LED white light.

[0005] The technical solution for achieving the purpose of the present invention is:

[0006] (1) introducing carboxylic acid groups, amine groups, and hydroxyl groups into the structure of the base fiber fabric by chemical grafting to obtain fiber fabrics containing the above functional groups;

[0007] (2) dispersing a certain amount of sodium bismuthate, metal salt, and polyvinyl alcohol in a 1 mol / L sodium hydroxide solution, stirring evenly at room temperature, and then transferring to a polytetrafluoroethylene-lined reactor, hydrothermally reacting at 100-180° C. for 10-60 minutes, cooling, separating the solid and liquid, washing with water to neutrality, and drying to obtain a photocatalyst powder A; pyrolyzing at least one of urea, melamine, and melamine under anaerobic conditions to obtain a photocatalyst powder B; dispersing the photocatalyst powder A and the photocatalyst powder B in a mixed solvent in a certain proportion, exfoliating the photocatalyst under ultrasonic conditions, and self-assembling and compounding to obtain a photocatalyst dispersion;

[0008] (3) The photocatalyst dispersion is evenly coated on the surface of the multifunctional fiber fabric, and aged at a certain temperature to cause the fiber fabric to swell and form a stable chemical bond between the photocatalyst and the functional group. After washing and drying, the photocatalytic fiber fabric is obtained.

[0009] Preferably, the base fiber fabric described in step (1) is polyacrylonitrile fiber, cotton fiber, or activated carbon fiber.

[0010] Preferably, the metal salt described in step (2) is at least one of the nitrates, chlorides or acetates of iron, manganese, cerium or bismuth, the mass ratio of the metal salt (in terms of metal element) to sodium bismuthate (in terms of bismuth element) is 0.1 to 10:100, the mass ratio of the photocatalyst powders A and B is 100:0.1 to 20, and the mixed solvent is a mixture of an alcohol (at least one of methanol, ethanol and ethylene glycol) and an ionic liquid (at least one of 1-ethyl-3-methylimidazolium chloride, 1-butyl-3-methylimidazolium chloride and 1-allyl-3-methylimidazolium chloride), and the mixing volume ratio is 100:1-10.

[0011] Preferably, the coating method in step (3) includes but is not limited to scraping, spraying, dipping, roller coating and brushing, etc., the aging temperature is 60-120°C, and the coating amount of the photocatalyst under the preferred conditions is 1-10 mg / cm 2 Fiber fabric.

[0012] The fiber fabric prepared by the above method is used for LED-driven catalytic antibacterial and environmental purification. The specific application method is: directly add the photocatalytic fiber fabric into the water body contaminated by organic matter or pathogenic bacteria, react in a dark environment for 1 hour until adsorption-desorption equilibrium, and then turn on the LED light source (power 3-5W, wavelength 380-760nm) for photocatalytic degradation or sterilization reaction.

[0013] The innovation of the present invention is as follows: (1) In order to achieve the excellent photocatalytic activity of the photocatalyst under ultra-low power LED white light irradiation, the present invention introduces metal salts and polyvinyl alcohol in the hydrothermal reaction, significantly shortens the hydrothermal preparation time of the powder photocatalyst A, and constructs a polycrystalline structure photocatalyst with rich oxygen vacancies. On the other hand, it is ultrasonically compounded with the powder photocatalyst B to further enrich the oxygen vacancies and construct a heterogeneous structure. (2) In order to achieve stable and efficient loading of the powder photocatalyst in the matrix fiber fabric structure, the present invention introduces a variety of functional groups into the matrix fiber structure, and introduces an ionic liquid with excellent swelling effect on the matrix fiber into the dispersion solvent, which helps the powder catalyst to form a stable chemical bond with the matrix fiber.

[0014] Compared with the prior art, the present invention has the following technical effects:

[0015] (1) The LED white light driven catalytic antibacterial and environmental purification fiber fabric constructed by the present invention has a wide light absorption range (covering the full spectrum of ultraviolet light, visible light, and near-infrared light), and can effectively utilize ultra-low power LED white light to achieve efficient removal of pathogenic bacteria and environmental pollutants;

[0016] (2) There is a chemical bond between the photocatalyst powder and the fiber fabric, which effectively avoids the problems of easy loss of photocatalyst powder, difficulty in recycling, and secondary pollution to the environment;

[0017] (3) The photocatalytic fiber fabric has flexible application forms. It can be directly added to water bodies, or made into filter beds, filter bags, etc., to purify polluted water bodies at a certain flow rate;

[0018] (4) The method for preparing LED white light driven catalytic antibacterial and environmental purification fiber fabric disclosed in the present invention has the advantages of simple operation, low cost, and green environmental protection. It is suitable for industrial production and has good industrial application prospects in the fields of environmental pollution purification and antibacterial sterilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1The ultraviolet-visible-near infrared light absorption spectrum of the powder photocatalyst prepared by the present invention;

[0020] Figure 2 The photocatalytic fiber fabric prepared in the present invention shows the removal effect of sulfonamide antibiotics (left) and Staphylococcus aureus (right) under the irradiation of ultra-low power LED white light;

[0021] Figure 3 Optical photograph (upper), scanning electron microscope photograph (lower left) and EDS element distribution photograph (lower right) of the photocatalytic fiber fabric prepared in the present invention after three cycles of use. DETAILED DESCRIPTION

[0022] In order to facilitate understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. Several embodiments of the present invention are given. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0023] In order to better describe the present invention in detail, the following embodiments are listed:

[0024] Embodiment 1:

[0025] Weigh 3.160g of sodium bismuthate dihydrate, 0.015g of ferric nitrate nonahydrate, and 5mL of polyvinyl alcohol and disperse them in a 1mol / L sodium hydroxide dilute solution, stir for 0.5 hours to form a uniform suspension; transfer the suspension into a 100mL polytetrafluoroethylene-lined reactor and perform hydrothermal reaction at 180°C for 10 minutes; separate, wash, and dry after the reaction to obtain powder photocatalyst A-1. Weigh 10g of urea and thermally polymerize it at 550°C in a muffle furnace for 2 hours to prepare powder photocatalyst B-1.

[0026] 1.000g of powdered photocatalyst A-1 and 0.001g of powdered photocatalyst B-1 were dispersed in a mixed solvent of methanol and 1-ethyl-3-methylimidazolium chloride (volume ratio 100:1), and ultrasonicated until an emulsion dispersion was formed to obtain a photocatalyst dispersion C-11 with a concentration of about 2mg / mL. 2mL of photocatalyst dispersion C-11 was taken and evenly coated on 1cm×1cm amino-modified acrylic fiber fabric in batches. After aging in an oven at 100℃, it was washed and dried to obtain a loading of about 3.7mg / cm 2 Photocatalytic fiber fabric 1.

[0027] The light absorption properties of powder photocatalysts A-1, B-1 and composite photocatalyst C-11 were analyzed by solid UV-visible-near infrared spectrometer. Figure 1As shown in the figure, the powder photocatalyst B-1 can only absorb ultraviolet light and visible light below 460nm, while the powder photocatalysts A-1 and C-11 can absorb the full spectrum LED including ultraviolet light, visible light and near infrared light. This shows that the powder photocatalyst prepared by the present invention has excellent full spectrum absorption ability.

[0028] Embodiment 2:

[0029] Weigh 3.160g of sodium bismuthate dihydrate, 0.075g of tetrahydrated manganese chloride, and 10mL of polyvinyl alcohol and disperse them in a 1mol / L sodium hydroxide dilute solution, stir for 0.5 hours to form a uniform suspension; transfer the suspension into a 100mL polytetrafluoroethylene-lined reactor and perform hydrothermal reaction at 160°C for 30 minutes; separate, wash, and dry after the reaction to obtain powder photocatalyst A-2. Weigh 10g of melamine and thermally polymerize it at 550°C in a muffle furnace for 2 hours to prepare powder photocatalyst B-2.

[0030] 1.000g of powdered photocatalyst A-2 and 0.010g of powdered photocatalyst B-2 were dispersed in a mixed solvent of ethanol and 1-butyl-3-methylimidazolium chloride (volume ratio 100:5), and ultrasonicated until an emulsion dispersion was formed to obtain a photocatalyst dispersion C-22 with a concentration of about 2mg / mL. 2mL of photocatalyst dispersion C-22 was taken and evenly coated on a 1cm×1cm carboxylic acid-modified acrylic fiber fabric in batches. After aging in an oven at 120°C, it was washed and dried to obtain a loading of about 3.5mg / cm 2 Photocatalytic fiber fabric 2.

[0031] Embodiment 3:

[0032] Weigh 3.160g of sodium bismuthate dihydrate, 0.243g of bismuth nitrate pentahydrate, and 10mL of polyvinyl alcohol and disperse them in a 1mol / L sodium hydroxide solution, stir for 0.5 hours to form a uniform suspension; transfer the suspension into a 100mL polytetrafluoroethylene-lined reactor and perform hydrothermal reaction at 140°C for 60 minutes; separate, wash, and dry after the reaction to obtain powder photocatalyst A-3. Weigh 10g of melamine and thermally polymerize it at 550°C in a muffle furnace for 2 hours to prepare powder photocatalyst B-3.

[0033] 1.000g of powdered photocatalyst A-3 and 0.100g of powdered photocatalyst B-3 were dispersed in a mixed solvent of ethanol and 1-allyl-3-methylimidazolium chloride (volume ratio 100:10), and ultrasonicated until an emulsion dispersion was formed to obtain a photocatalyst dispersion C-3 with a concentration of about 2mg / mL. 1mL of photocatalyst dispersion C-33 was taken and evenly coated on a quaternary ammonium modified cotton fiber fabric of 1cm×1cm in batches, aged in an oven at 60℃, washed and dried, and a loading of about 1.2mg / cm was obtained. 2 Photocatalytic fiber fabric 3.

[0034] Embodiment 4:

[0035] Weigh 3.160g of sodium bismuthate dihydrate, 0.473g of cerium acetate, and 20mL of polyvinyl alcohol and disperse them in a 1mol / L sodium hydroxide solution, stir for 0.5 hours to form a uniform suspension; transfer the suspension into a 100mL polytetrafluoroethylene-lined reactor, and perform a hydrothermal reaction at 120°C for 30 minutes; after the reaction, separate, wash, and dry to obtain a powder photocatalyst A-4. The preparation method of the powder photocatalyst B-1 is the same as in Example 1.

[0036] 1.000g of powdered photocatalyst A-4 and 0.200g of powdered photocatalyst B-1 were dispersed in a mixed solvent of ethanol and 1-butyl-3-methylimidazolium chloride (volume ratio 100:5), and ultrasonicated until an emulsion dispersion was formed to obtain a photocatalyst dispersion D-41 with a concentration of about 2mg / mL. 5mL of photocatalyst dispersion D-41 was taken and evenly coated on a 1cm×1cm hydroxyl-modified activated carbon fiber fabric in batches. After aging in an oven at 120°C, it was washed and dried to obtain a loading of about 9.8mg / cm 2 Photocatalytic fiber fabric 4.

[0037] Application Example 1:

[0038] The photocatalytic fiber fabrics 1-4 prepared in Examples 1-4 were dispersed in a sulfonamide antibiotic (sulfadimethoxine 0.05mmol / L) solution, with the dosage of the photocatalytic fiber fabric being 0.2g / L. The reaction was conducted for 1 hour in the dark to ensure that the adsorption-desorption equilibrium was reached. Then, the LED white light source was turned on, and samples were taken and filtered after a certain reaction time. The pollutant concentration after the reaction was tested using a high performance liquid chromatograph. The sulfadimethoxine solution without fiber fabric was used as a blank control. The experimental results are shown in FIG. Figure 2 (Left) shown.

[0039] Application Example 2:

[0040] The photocatalytic fiber fabric 1 prepared in Example 1 and its corresponding base fiber fabric (i.e., amine-modified acrylic fiber fabric) were dispersed in a solution having a concentration of about 107 CFU / mL, and in the logarithmic growth phase of Staphylococcus aureus solution, turn on the LED white light source, take samples after a certain reaction time, and use the bacterial plate culture experiment to test the bacterial concentration after the reaction. The bacterial solution without fiber fabric (LED white light alone) is used as the blank control, and the bacterial solution without fiber fabric and without light is used as the dark control. The experimental results are shown in Figure 2 (right) shown.

[0041] The results showed that except for photocatalytic fiber fabric 3, after 6 hours of LED white light irradiation, the removal rates of sulfonamide antibiotics by the other photocatalytic fiber fabrics were all above 95%, especially photocatalytic fiber fabric 4, which had the fastest rate; after 1 hour of LED white light irradiation, photocatalytic fiber fabric 1 could completely inactivate Staphylococcus aureus, which was much faster than the LED white light alone (complete inactivation required 4 hours) and the synergistic effect of LED white light and corresponding matrix fiber (complete inactivation required 3 hours).

[0042] Figure 3 The optical photographs (upper) of the photocatalytic fiber fabrics 1-4 prepared in Examples 1-4 after three cycles of use, the scanning electron microscope photograph (lower left) and EDS element distribution photograph (lower right) of the photocatalytic fiber fabric 2 prepared in Example 2 after three cycles of use. It can be seen that the powdered photocatalyst is evenly and stably distributed on the surface of the fiber fabric and can be recycled many times.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention is described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a photocatalytic fiber fabric, characterized in that: Prepared by the following method: (1) Introducing carboxylic acid groups, amine groups or hydroxyl groups into the structure of the base fiber fabric by chemical grafting to obtain fiber fabrics containing carboxylic acid groups, amine groups or hydroxyl functional groups; (2) dispersing a certain amount of sodium bismuthate, metal salt and polyvinyl alcohol in a 1 mol / L sodium hydroxide solution, stirring evenly at room temperature, then transferring to a polytetrafluoroethylene-lined reactor, hydrothermally reacting at 100-180°C for 10-60 minutes, cooling and separating the solid and liquid, washing with water until neutral, and drying to obtain a photocatalyst powder A; pyrolyzing at least one of urea and melamine under anaerobic conditions to obtain a photocatalyst powder B; dispersing the photocatalyst powder A and the photocatalyst powder B in a mixed solvent in a certain proportion, exfoliating the photocatalyst under ultrasonic conditions and self-assembling and compounding to obtain a photocatalyst dispersion C; wherein the metal salt is at least one of nitrate, chloride or acetate of iron, manganese or cerium, and the mixed solvent is a mixture of alcohol and ionic liquid; (3) uniformly coating the photocatalyst dispersion C on the surface of the fiber fabric obtained in step (1), aging the fiber fabric at a certain temperature to cause the fiber fabric to swell and form a stable chemical bond between the photocatalyst and the functional group, and washing and drying to obtain a photocatalytic fiber fabric; The base fiber fabric in step (1) is polyacrylonitrile fiber or activated carbon fiber; The alcohol in step (2) is at least one of methanol, ethanol and ethylene glycol; the ionic liquid is at least one of 1-ethyl-3-methylimidazolium chloride and 1-butyl-3-methylimidazolium chloride; and the mixed volume ratio of the two is 100:1-10.

2. The preparation method according to claim 1, characterized in that: The mass ratio of the metal salt and sodium bismuthate in step (2) is 0.1-10:100, calculated as metal element and bismuth element respectively, and the mass ratio of photocatalyst powder A to photocatalyst powder B is 100:0.1-20.

3. The preparation method according to claim 1, characterized in that: The coating in step (3) is performed by one or more of scraping, spraying, dipping or roller coating, the aging temperature is 60-120°C, and the photocatalyst coating amount is 1-10 mg / cm 2 Fiber fabric.

4. The photocatalytic fiber fabric prepared according to the preparation method according to any one of claims 1 to 3.

5. Application of the photocatalytic fiber fabric according to claim 4 to achieve photocatalytic antibacterial and environmental purification under the drive of LED white light.

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