Efficient photocatalyst formaldehyde scavenger and preparation method thereof

Abstract

The invention relates to the technical field of formaldehyde removal, in particular to an efficient photocatalyst formaldehyde scavenger and a preparation method thereof. The problems that a photocatalyst scavenging agent is limited by light, is prone to agglomeration, low in stability, low in formaldehyde scavenging efficiency and not environmentally friendly enough are solved. The efficient photocatalyst formaldehyde scavenger is prepared by taking a photocatalyst, a trapping agent, a plant pigment and a dispersion stabilizer as main raw materials. By doping titanium dioxide to form a heterojunction, the effect of catalytic degradation of formaldehyde by titanium dioxide in a dark environment is improved. By controlling the conditions of the preparation process of the doped titanium dioxide, the doped titanium dioxide is loaded on the MOFs material, so that the specific surface area in contact with formaldehyde is increased, and the efficient photocatalyst formaldehyde scavenger is prevented from being gathered. Through synthesis, different types of formaldehyde trapping agents are added and cooperate with the photocatalyst, so that the formaldehyde removal effect is improved. By adding the plant pigment, the obtained scavenging agent has a good formaldehyde scavenging effect, is green and environment-friendly, and smells fresh.

Description

Technical Field

[0001] The invention relates to the technical field of formaldehyde removal, in particular to a high-efficiency photocatalyst formaldehyde scavenger and a preparation method thereof. Background Art

[0002] Formaldehyde is a colorless, soluble, irritating gas that is teratogenic and carcinogenic to humans. When inhaled through the respiratory tract, it damages the skin and mucous membranes of the human body, reduces the body's immunity, and also has varying degrees of damage to human organs and tissues. However, formaldehyde is very common in daily life, especially in the field of decoration. After a new house is decorated, formaldehyde will be released from artificial boards, wallpapers, adhesives, wall coverings, and a variety of paint and decoration materials. Especially under high temperature conditions, the amount of formaldehyde released will increase further.

[0003] Therefore, it is very important to reduce and remove the formaldehyde that releases high concentration. The simplest way to remove formaldehyde is ventilation, but the time of removal is long. There are also ways to remove formaldehyde by physical or chemical means, such as physical methods using activated carbon, diatomaceous earth, bamboo charcoal, etc. for adsorption, but the adsorption capacity is limited, which easily causes secondary pollution. Chemical methods remove formaldehyde and have high efficiency, such as the shell inorganic functional coating of patent CN116554747B anti-formaldehyde and its preparation method, by using functional formaldehyde removal emulsion and shell powder, titanium dioxide as raw materials to prepare functional coating, the preparation process is simple, the raw materials are easy to obtain, and the removal effect of formaldehyde is obvious. However, the functional formaldehyde removal emulsion contains hydrazide compounds, and long-term use can cause damage to human health, and the product does not have environmental protection.

[0004] Photocatalytic removal of formaldehyde is also an effective method in chemical removal methods, but it has certain limitations. It can only achieve good formaldehyde removal within a small range of visible light. In actual application, such as at night in the dark, the formaldehyde removal effect decreases. To solve this problem, patent CN114471146B discloses a green and odorless formaldehyde scavenger and its preparation method. The formaldehyde scavenger is prepared by synthesizing zeolite-silver / bismuth oxychloride / carbon nitride / titanium dioxide as a photocatalyst, and a dispersing stabilizer, flavor and buffer, which effectively expands the utilization of titanium dioxide for visible light and improves the removal effect of formaldehyde. In addition to using carbon nitride to dope carbon dioxide, patent CN112121791B discloses a photocatalytic formaldehyde removal catalyst based on titanium dioxide / platinum atomic clusters, its preparation method and application. The photocatalytic formaldehyde removal catalyst is prepared by using chloroplatinic acid, titanium dioxide, polyvinyl pyrrolidone and sodium borohydride as raw materials. The preparation method is simple, and the formaldehyde removal rate is high after 180 days of continuous use and the stability is good.

[0005] Patent CN112107998B discloses an environmentally friendly composite nano-photocatalyst formaldehyde scavenger and its preparation method, which uses deionized water, photocatalyst, dispersant, formaldehyde inducer and modified diatomaceous earth as raw materials. The formaldehyde inducer contains tea polyphenols and plant extracts, and the polyphenols therein can capture formaldehyde, and has a good formaldehyde removal effect and is green and environmentally friendly. However, modified diatomaceous earth is used as a carrier, and is physically mixed with the photocatalyst and other substances. The photocatalyst is unevenly distributed on the modified diatomaceous earth, and the contact area with formaldehyde is reduced.

[0006] Although certain progress has been made in the prior art for removing formaldehyde, there are still problems such as formaldehyde removal being limited by light, photocatalyst formaldehyde scavengers being prone to agglomeration, low formaldehyde capture and removal rates, instability, and poor durability.

[0007] Therefore, a high-efficiency photocatalyst formaldehyde scavenger and a preparation method thereof are proposed. Summary of the invention

[0008] The object of the present invention is to provide a high-efficiency photocatalyst formaldehyde scavenger and a preparation method thereof. The present invention mixes a pigment, a photocatalyst, a trapping agent, a dispersion stabilizer and water to obtain a high-efficiency photocatalyst formaldehyde scavenger. By using a powder material to dope titanium dioxide and changing the preparation conditions of the doped titanium dioxide, the obtained high-efficiency photocatalyst formaldehyde scavenger can remove formaldehyde without being restricted by light conditions. By loading the doped titanium dioxide on an in-situ generated MOFs material, the specific surface area of ​​the high-efficiency photocatalyst formaldehyde scavenger in contact with formaldehyde is increased, formaldehyde is captured and the photocatalyst is prevented from agglomerating. By synthesizing a trapping agent one and using it in combination with a trapping agent two and a trapping agent three, the formaldehyde removal rate is improved. By adding a plant pigment and using it in combination with each component, the photocatalyst's photocatalytic activity in removing formaldehyde is improved, and it is green and environmentally friendly.

[0009] In one aspect, the present invention provides a method for preparing a high-efficiency photocatalyst formaldehyde scavenger, comprising the following steps:

[0010] Dissolve 0-0.7 parts of pigment in water, add 5.5-9 parts of photocatalyst, 0-14 parts of trapping agent and 0-3 parts of dispersion stabilizer, stir and homogenize by ultrasonication to obtain a high-efficiency photocatalyst formaldehyde scavenger; the trapping agent includes trapping agent 1, trapping agent 2 and trapping agent 3;

[0011] The powder material is dispersed in anhydrous ethanol to obtain a powder liquid; the anhydrous ethanol, hydrochloric acid, water and 0-7.8 parts of the powder liquid are added to a tetrabutyl titanate solution, stirred for 30-48 hours, dried and ground into a gel powder; the gel powder is put into a tubular furnace, roasted at a roasting temperature of 400-550° C. for 2-7 hours, and cooled to obtain doped titanium dioxide;

[0012] Add 1.2-2.0 parts of the doped titanium dioxide to a cobalt nitrate solution, stir, ultrasonicate, then add a polyacrylonitrile solution, stir to obtain a spinning solution; electrospin the spinning solution to obtain nano-doped titanium dioxide-cobalt fibers; dissolve 3.8-4.4 parts of 2-methylpyrazole and N,N-dimethylethylenediamine in the anhydrous ethanol to obtain a mixed solution; immerse the nano-doped titanium dioxide-cobalt fibers in the mixed solution, grow in situ for 22-30 hours, wash, dry, crush and grind, and obtain the photocatalyst;

[0013] Cobalt nitrate and doped titanium dioxide are first uniformly mixed, and then electrospun. The doped titanium dioxide is uniformly dispersed in the fiber containing cobalt nitrate and polyacrylonitrile. Under immersion conditions, N,N-dimethylethylenediamine is used as a template, and 2-methylpyrazole is coordinated with cobalt metal to form ZIF-67MOFs materials coordinated with organic compounds and metals. MOFs materials have a large specific surface area, and doped titanium dioxide is uniformly distributed in them. MOFs materials play a role in capturing formaldehyde, and also have the function of uniformly dispersing doped titanium dioxide, avoiding the agglomeration of doped titanium dioxide, thereby improving the removal effect of high-efficiency photocatalyst formaldehyde scavengers on formaldehyde.

[0014] Disperse carboxymethyl cellulose in water, add 11.0-11.8 parts of diethylenetriamine and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride after heating, adjust the pH of the system to 3, and react to obtain a diethylenetriamine grafted cellulose solution; add 29.0-45.9 parts of the capture agent three to the diethylenetriamine grafted cellulose solution, adjust the pH to 10.5, stir the reaction, filter, wash, and dry to obtain the capture agent one.

[0015] Carboxymethyl cellulose is modified. In the presence of a condensation agent and heating, the carboxyl group in the carboxymethyl cellulose is connected to diethylenetriamine through an amide bond. Then, the unreacted amino group in the diethylenetriamine reacts with the phenolic hydroxyl group in the scavenger three, thereby forming a composite structure of carboxymethyl cellulose-diethylenetriamine-scavenger three.

[0016] Carboxymethyl cellulose has a water-retaining effect, and the presence of diethylenetriamine increases the compatibility with the structure of the second capture agent. The second capture agent is a compound containing an enol-ketone structure, which can capture formaldehyde and react with it to remove formaldehyde. The third capture agent is a compound containing an ortho-phenolic hydroxyl structure. On the one hand, it has an antioxidant effect and maintains the activity of each component of the high-efficiency photocatalyst formaldehyde scavenger. On the other hand, it also has the effect of capturing formaldehyde and reacting chemically with it.

[0017] Preferably, the pigment is used in an amount of 0.3-0.7 parts; the capture agent is used in an amount of 10-14 parts.

[0018] Preferably, the dispersion stabilizer is zinc stearate; the amount of zinc stearate is 1-3 parts.

[0019] Preferably, the total amount of the pigment, the photocatalyst, the trapping agent and the dispersion stabilizer in the high-efficiency photocatalyst formaldehyde scavenger is 100 parts; the ratio of the trapping agent 1, the trapping agent 2 and the trapping agent 3 is 1:3:1.

[0020] Preferably, the preparation method of the pigment is as follows: use gauze to wipe off the dirt on the surface of the spider plant, use scissors to avoid the main vein to sample the leaves, and obtain square leaves with a side length of 0.5 cm; add the square leaves into a mortar and grind them to obtain leaf pulp; transfer the leaf pulp to an ethanol-water solution, ultrasonically stir for 6 hours to obtain an extract; filter the extract, and rotary evaporate to dryness to obtain the pigment; the ratio of ethanol to water in the ethanol-water solution is 19:1.

[0021] The main components of the pigment are chlorophyll a, chlorophyll b and anthocyanin. The excited state potential of the pigment is more negative than the energy level of titanium dioxide. Adsorption on the surface of titanium dioxide can promote the transfer of photogenerated electrons to the surface of titanium dioxide and improve the utilization rate of photons. The pigment is dispersed in the system and contacts with the doped titanium dioxide of the photocatalyst, and the catalytic activity is improved, which is conducive to the decomposition of formaldehyde.

[0022] Preferably, the powder material includes component one and component two; component one is one of tin telluride, lead telluride, lead selenide, mercury selenide, mercury telluride and indium antimonide; component two is tungsten oxide; the powder material is a mixture of component one and component two in a ratio of 4:1.

[0023] The impurity metal element tungsten is introduced into the anatase phase of titanium dioxide. Tungsten occupies the position of titanium atoms in the crystal phase. Further under light conditions, titanium dioxide produces electron hole-photogenerated electron pairs. The photogenerated electrons capture oxygen in the air to generate oxygen anions. The surface of titanium dioxide that has lost electrons captures water to form titanium dioxide, hydroxyl radicals and hydrogen ions. The hydroxyl radicals react with formaldehyde to form formaldehyde radicals, which further react with oxygen anions, hydrogen ions and water, thereby decomposing the formaldehyde into carbon dioxide and water.

[0024] Due to the large band gap of titanium dioxide, the generated electrons need to absorb a large amount of energy to migrate from the valence band to the conduction band, and then migrate to the surface of titanium dioxide to remove formaldehyde. Therefore, a good formaldehyde removal effect can be achieved in the ultraviolet and visible light regions. However, in the infrared light region, under the condition of no light, the photocatalyst's ability to remove formaldehyde is greatly reduced.

[0025] The band gaps of tin telluride and these powder materials decrease in turn, among which the band gap of carbon nitride is 3.06eV and the band gap of indium antimonide is only 0.18eV. They form heterojunctions with tungsten and titanium dioxide, and defects are formed on the surface of titanium dioxide. At the same time, the band gap is reduced to prevent the recombination of electron holes and photogenerated electrons. The prepared photocatalyst formaldehyde scavenger can achieve good formaldehyde removal in a dark environment.

[0026] Preferably, the powder liquid is used in an amount of 0.5-7.8 parts; the tetrabutyl titanate solution is obtained by dissolving tetrabutyl titanate in the anhydrous ethanol.

[0027] Preferably, the calcination temperature is 400-500° C. and the calcination time is 2.5-7 hours.

[0028] Preferably, the second capture agent is one of glycolic anhydride diacetate, methoxyacetic anhydride, ethoxy guaiacol acetate, and acetoethyl acetate; the third capture agent is one of quercetin, catechin, epicatechin gallate, and epigallocatechin gallate.

[0029] On the other hand, the present invention provides a high-efficiency photocatalyst formaldehyde scavenger, which comprises a pigment, a photocatalyst, a capture agent 1, a capture agent 2, a capture agent 3, a dispersion stabilizer and water; the high-efficiency photocatalyst formaldehyde scavenger is obtained by any one of the preparation methods described above; by changing the preparation conditions of doped titanium dioxide, the high-efficiency photocatalyst formaldehyde scavenger has a formaldehyde removal rate of 76.0%-99.8% in 24 hours under light conditions, and a formaldehyde removal rate of 52.8%-95.6% in 24 hours under dark conditions; the high-efficiency photocatalyst formaldehyde scavenger has a formaldehyde removal rate of 31.6%-57.1% in 0.5 hours, a formaldehyde removal rate of 68.0%-99.9% in 8 hours, and a formaldehyde removal rate of 68.0%-99.9% in 24 hours under light conditions. The formaldehyde removal rate is 77.3%-99.9%; by changing the preparation conditions of the photocatalyst, the formaldehyde removal rate of the high-efficiency photocatalyst formaldehyde scavenger is 47.8%-58.2% in 0.5h, 85.9%-99.9% in 8h, and 91.3%-99.9% in 24h; by changing the preparation conditions of the capture agent, the formaldehyde removal rate of the high-efficiency photocatalyst formaldehyde scavenger under the illumination conditions is 94.7%-99.9% in 24h; by changing the dosage of the preparation components of the high-efficiency photocatalyst formaldehyde scavenger, the formaldehyde removal rate of the high-efficiency photocatalyst formaldehyde scavenger under the illumination conditions after 0-month storage is 73.1%-99.4%, and the formaldehyde removal rate of the high-efficiency photocatalyst formaldehyde scavenger under the illumination conditions after 1-month storage is 64.6%-98.1%.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] 1. The present invention forms doped titanium dioxide by doping with powder materials, changes the type and amount of powder used, and controls the reaction conditions for preparing doped titanium dioxide. The bandgap width of doped titanium dioxide is reduced, and the prepared high-efficiency photocatalyst formaldehyde scavenger can achieve good formaldehyde removal in both light and dark environments, and the formaldehyde removal rate in a dark environment is lower than that in light conditions.

[0032] 2. The present invention obtains doped titanium dioxide by doping, controls the calcination temperature and time in the preparation process, and obtains a high-efficiency photocatalyst formaldehyde scavenger, which has a high formaldehyde removal rate after being used for 0.5h, 8h and 24h. As time goes by, the formaldehyde removal effect is further increased.

[0033] 3. The present invention spins a spinning solution containing cobalt nitrate, doped titanium dioxide and polyacrylonitrile, and then reacts with 2-methylpyrazole to in-situ grow MOFs fibers loaded with doped titanium dioxide, and further grinds to obtain a photocatalyst. Through electrostatic spinning and MOFs material loading doped titanium dioxide, the specific surface area of ​​the high-efficiency photocatalyst formaldehyde scavenger in contact with formaldehyde is increased, formaldehyde is captured and photocatalyst agglomeration is prevented, and the formaldehyde removal rate is high.

[0034] 4. The present invention uses the capture agent 2 and the capture agent 3 as raw materials of the high-efficiency photocatalyst formaldehyde scavenger, and simultaneously grafts the capture agent 3 and diethylenetriamine onto carboxymethyl cellulose to obtain the capture agent 1, thereby improving the compatibility and water retention of the components. The capture agent components are used in combination with the MOFs material in the photocatalyst to capture and remove formaldehyde, thereby improving the formaldehyde removal rate.

[0035] 5. The present invention prepares a pigment, adjusts the dosage of a photocatalyst, a trapping agent, a pigment and a dispersion stabilizer, and obtains a highly efficient photocatalyst formaldehyde scavenger that removes formaldehyde after being stored for 1 month, and the reduction value of the removal rate is small. The trapping agent captures and removes formaldehyde, the photocatalyst and the trapping agent act synergistically, and the use of the pigment improves the photocatalytic activity of the photocatalyst. In addition, the highly efficient photocatalyst formaldehyde scavenger prepared by the present invention has the fragrance of plants, is green and environmentally friendly, and is suitable for daily use. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a graph showing the formaldehyde removal rate results at 0.5h, 8h and 24h of Example 32 of the present invention;

[0037] Figure 2 This is a graph showing the formaldehyde removal rate results of Example 42 of the present invention. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] See also Figure 1 to Figure 2 The present invention provides a high-efficiency photocatalyst formaldehyde scavenger and a preparation method thereof, and the technical scheme is as follows:

[0040] The substance information involved in the present invention is as follows:

[0041] Indium antimonide CAS: 5593-70-4; Mercury telluride CAS: 1312-41-0; Mercury selenide CAS: 20601-83-6; Lead selenide CAS: 12069-00-0; Lead telluride CAS: 1314-91-6; Tin telluride CAS: 12040-02-7; Quercetin CAS: 117-39-5; Catechin CAS: 7295-85-4; Epigallocatechin gallate CAS: 1257-08-5; (-)-Epigallocatechin gallate CAS: 989-51-5.

[0042] Example 1

[0043] 0.5 parts of pigment are dissolved in water, and then 8 parts of photocatalyst and 12 parts of trapping agent are added thereto, and finally 1 part of dispersing stabilizer zinc stearate is added, and ultrasonic homogenization is performed after stirring to obtain a high-efficiency photocatalyst formaldehyde scavenger; the total amount of each component of the high-efficiency photocatalyst formaldehyde scavenger is 100 parts. The trapping agent includes trapping agent 1, trapping agent 2 and trapping agent 3; the ratio of the number of parts of trapping agent 1, trapping agent 2 and trapping agent 3 is 1:3:1; trapping agent 2 is ethyl acetate; and trapping agent 3 is quercetin.

[0044] The preparation method of the photocatalyst is as follows: 69 parts of tetrabutyl titanate are dissolved in 1000 parts of anhydrous ethanol to obtain a tetrabutyl titanate solution; 40 parts of anhydrous ethanol, 25 parts of hydrochloric acid and 35 parts of water are mixed to obtain a mixed liquid; 2 parts of powder material are dispersed in 58 parts of anhydrous ethanol to obtain a powder liquid; the powder material is a component of tin telluride and a component of tungsten dioxide mixed in a ratio of 4:1; under stirring, 50 parts of the mixed liquid and 0.5 parts of the powder liquid are added to 250 parts of the tetrabutyl titanate solution, and stirring is continued at room temperature for 36 hours to obtain a gel material; the gel material is dried and ground into a gel powder; the gel powder is put into a tubular furnace, roasted at 450°C for 4 hours, and cooled to obtain doped titanium dioxide.

[0045] 2.6 parts of cobalt nitrate are added to 35 parts of DMF, and stirred to dissolve to obtain a cobalt nitrate solution; 1.5 parts of doped titanium dioxide are added to the cobalt nitrate solution, and the mixture is stirred for 2 hours and then ultrasonically treated to obtain a doped titanium dioxide-cobalt mixed solution; 4.8 parts of polyacrylonitrile are dissolved in an organic solution of 40 parts of DMF and 10 parts of anhydrous ethanol to obtain a polyacrylonitrile solution; the polyacrylonitrile solution is added to the titanium-cobalt mixed solution, and the mixture is stirred for 12 hours to obtain a spinning solution; the spinning solution is electrostatically spun to obtain nano-doped titanium dioxide-cobalt fibers; 4 parts of 2-methylpyrazole and 0.5 parts of N,N-dimethylethylenediamine are dissolved in 120 parts of anhydrous ethanol to obtain a mixed solution; the nano-doped titanium dioxide-cobalt fibers are immersed in the mixed solution, and grown in situ for 24 hours to obtain MOFs-nano-doped titanium dioxide fibers; the nano-doped titanium dioxide is washed, dried at 80°C for 10 hours, and crushed and ground to an average particle size of 80 nm to obtain a photocatalyst.

[0046] The electrospinning conditions were as follows: the positive electrode voltage was 20 kV, the drum speed was 140 rpm, the receiving distance was 20 cm, the ambient temperature was 25 °C, the humidity was 27%, and the injection speed was 0.08 mm / min.

[0047] The preparation method of the pigment is as follows: use gauze to wipe off the dirt on the surface of the spider plant, use scissors to sample the leaves avoiding the main veins, and cut them into square leaves with a side length of 0.5 cm; add 30 parts of the square leaves into a mortar and grind them to obtain leaf pulp; transfer the leaf pulp to 1000 parts of ethanol aqueous solution (the ratio of ethanol to water is 19:1), ultrasonically stir for 6 hours to obtain an extract; filter the extract, and rotary evaporate to dryness to obtain the pigment.

[0048] The preparation method of capture agent one is as follows: 24.2 parts of carboxymethyl cellulose are dispersed in 300 parts of water to obtain a carboxymethyl cellulose solution; the carboxymethyl cellulose solution is heated to 60°C, and 11.4 parts of diethylenetriamine and 0.04 parts of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride are added thereto under stirring, and the pH of the system is adjusted to 3 with hydrochloric acid to obtain a reaction solution; the reaction solution is stirred for 12 hours to obtain a diethylenetriamine grafted cellulose solution; 36.3 parts of capture agent triquercetin are added to the diethylenetriamine grafted cellulose solution, the pH is adjusted to 10.5 with potassium hydroxide, the reaction is stirred for 6 hours, filtered, washed, and dried to obtain capture agent one.

[0049] Example 2-13

[0050] Comparative Examples 1-4

[0051] Different from Example 1, the conditions of the preparation process of doped titanium dioxide are changed, as shown in Table 1.

[0052] Table 1 Specific conditions of the preparation method of doped titanium dioxide

[0053]

[0054]

[0055] Embodiment 14

[0056] The high-efficiency photocatalyst formaldehyde scavengers prepared in Examples 1-13 and Comparative Examples 1-4 were subjected to formaldehyde removal tests. The specific test method is as follows: 3 In a sealed glass reaction device, 2 portions of high-efficiency photocatalyst formaldehyde scavenger were evenly sprayed on the four walls and upper and lower surfaces of the reaction device, and the initial degradation concentration was 1.05 mg / m 3 The formaldehyde removal rate was determined by using the PPM-400ST formaldehyde analyzer to test the concentration of formaldehyde in the sealed glass after 24 hours. The calculation formula for the removal rate is as follows: The effects of removing formaldehyde under light and dark conditions were tested respectively, and the test results are shown in Table 2.

[0057] Table 2 Formaldehyde removal effect under light and dark conditions

[0058]

[0059]

[0060] The high-efficiency photocatalyst formaldehyde scavenger prepared in the embodiments of the present invention and the comparative examples has a 24-hour formaldehyde scavenging rate of 76.0%-99.8% under light conditions, and a 24-hour formaldehyde scavenging rate of 52.8%-95.6% under dark conditions. In Examples 1-6, the scavenging ability of the scavenger to formaldehyde is changed by changing the type of powder material doped with titanium dioxide. In Example 6, indium antimonide and tungsten oxide are used as doping raw materials, and the scavenger obtained has the highest formaldehyde scavenging rate, which is 98.8% under light conditions and 94.1% under dark conditions. In Examples 6-11, by increasing the amount of powder liquid, the effect of removing formaldehyde changes accordingly, and the formaldehyde scavenging rate shows a trend of first increasing and then decreasing. In Example 10, the scavenging rate reaches the highest. When the amount of powder liquid is too high, titanium dioxide cannot form a good anatase phase. As shown in Comparative Example 1, the photocatalytic effect of removing formaldehyde decreases. The results of Examples 11-13 show that the prepared high-efficiency photocatalyst formaldehyde scavenger has a good formaldehyde scavenging effect when the stirring time is controlled within the range of 30-36h. When the stirring time is increased to 48h, due to the long stirring time, the components in the powder gradually precipitate to the surface of the gel material, and the uniformity between the components is reduced. In Comparative Example 2, no powder liquid is added, and the obtained scavenger has the lowest efficiency in removing formaldehyde. Comparative Example 4 uses carbon nitride to modify titanium dioxide, and the formaldehyde removal rate under light and dark conditions is lower than that of the high-efficiency photocatalyst formaldehyde scavenger prepared in the embodiment. In summary, the high-efficiency photocatalyst formaldehyde scavenger prepared by the present invention can achieve a good formaldehyde removal effect in the visible light region, and can also achieve formaldehyde removal in the infrared light region of a dark environment. The formaldehyde removal rate in a dark environment is lower than the formaldehyde removal effect under light conditions, but the scavenger of the embodiment has a minimum formaldehyde removal rate of more than 80% in the dark.

[0061] Examples 15-20

[0062] Different from Example 10, the calcination conditions of doped titanium dioxide are changed, as shown in Table 3.

[0063] Embodiment 21

[0064] The formaldehyde removal effect of the high-efficiency photocatalyst formaldehyde scavenger prepared in Examples 10, 15-20 and Comparative Example 5 was tested to investigate the formaldehyde removal effect of the high-efficiency photocatalyst formaldehyde scavenger under light conditions for 0.5h, 8h and 24h. The test method was carried out with reference to Example 14. The final test results are shown in Table 3.

[0065] By changing the calcination temperature and time, the high-efficiency photocatalyst formaldehyde scavenger prepared by the present invention has a formaldehyde scavenging rate of 31.6%-57.1% in 0.5h, 68.0%-99.9% in 8h, and 77.3%-99.9% in 24h under light conditions. The results of Examples 10, 15-17, 19-20 show that by controlling the calcination temperature in the range of 400-500°C and the calcination time in 3-7h, the photocatalyst formaldehyde scavenger has a good scavenging effect on formaldehyde, but the calcination temperature and time exceed this range, as shown in Comparative Example 5, the scavenging rate of the scavenger on formaldehyde after 24h is only 77.3%. The results of Examples 17 and 18 show that the formaldehyde scavenging rate is reduced by shortening the calcination time at the same calcination temperature. It may be that with the shortening of the calcination time, the anatase phase cannot be formed, so the good scavenging effect of the photocatalyst cannot be achieved. The calcination temperature of Comparative Example 5 is too high, and the anatase phase of titanium dioxide has been completely transformed into the rutile phase. The lattice of the rutile phase is dense and cannot catalytically eliminate formaldehyde under light conditions.

[0066] Table 3 Calcination conditions of doped titanium dioxide

[0067]

[0068] Examples 22-31

[0069] Different from Example 17, the preparation process of the photocatalyst is changed, as shown in Table 4.

[0070] Table 4 Changes in conditions during the preparation of photocatalysts

[0071]

[0072]

[0073] Comparative Example 6

[0074] Different from Example 17, no electrospinning process was performed to prepare the photocatalyst, and other preparation conditions remained unchanged.

[0075] 2.6 parts of cobalt nitrate are added to 35 parts of DMF, and the mixture is stirred and dissolved to obtain a cobalt nitrate solution; 1.5 parts of doped titanium dioxide are added to the cobalt nitrate solution, and the mixture is stirred for 2 hours and then ultrasonicated to obtain a doped titanium dioxide-cobalt mixed solution; 4 parts of 2-methylpyrazole and 0.5 parts of N,N-dimethylethylenediamine are dissolved in 120 parts of anhydrous ethanol to obtain a mixed solution; the mixed solution is added to the doped titanium dioxide-cobalt mixed solution, and the stirring is continued for 10 hours. The product is filtered, washed, and dried to obtain a photocatalyst.

[0076] Embodiment 32

[0077] The high-efficiency photocatalyst formaldehyde scavengers prepared in Examples 22-31 and Comparative Example 6 were tested for formaldehyde removal performance. The specific test method was carried out according to the test method of Example 14. The formaldehyde removal rate test results under light conditions are shown in Tables 5 and Figure 1 shown.

[0078] Table 5 Effect of photocatalyst preparation conditions on formaldehyde removal effect

[0079]

[0080]

[0081] As shown in Table 5, the high-efficiency photocatalyst formaldehyde scavenger prepared by the present invention has a formaldehyde scavenging rate of 47.8%-58.2% in 0.5h, 85.9%-99.9% in 8h, and 91.3%-99.9% in 24h under light conditions. In the process of preparing the photocatalyst, by changing the amount of doped titanium dioxide and 2-methylpyrazole and the in-situ growth time, the high-efficiency photocatalyst formaldehyde scavenger obtained has a good formaldehyde scavenging effect. Figure 1 As a result, in Examples 22-25, with the increase in the amount of doped titanium dioxide, the formaldehyde removal rate showed a trend of first increasing and then decreasing. The loading sites in the MOFs material were certain. When the loading of doped titanium dioxide reached an appropriate range, such as Example 24, the catalytic effect was best when the amount of doped titanium dioxide was 1.6 parts. When the amount of doped titanium dioxide in Example 25 was further increased, the MOFs material might be blocked, so the catalytic removal of formaldehyde was reduced. The results of Examples 24, 26-28 show that controlling the amount of 2-methylpyrazole in the range of 3.8-4.2 parts is conducive to the complete formation of the MOFs material, thereby improving the formaldehyde removal effect. The results of Examples 26, 29-31 show that the in-situ growth time increases, and the formaldehyde removal first increases and then stabilizes. Comparative Example 6 does not use electrostatic spinning to prepare the photocatalyst, and the doped titanium dioxide is unevenly dispersed in the photocatalyst. The MOFs material loaded with doped titanium dioxide is prone to agglomeration, and the formaldehyde removal rate is reduced.

[0082] Examples 33-41

[0083] Different from Example 26, the following preparation conditions are changed, as shown in Table 6.

[0084] Table 6 Changes in conditions during the capture agent preparation process

[0085]

[0086] Embodiment 42

[0087] The high-efficiency photocatalyst formaldehyde scavenger prepared in Examples 33-41 was tested for its formaldehyde scavenging effect under light conditions. The test results are as follows: Figure 2 shown.

[0088] Figure 2 It shows that the high-efficiency photocatalyst formaldehyde scavenger prepared by the present invention has a formaldehyde scavenging rate of 94.7%-99.9% under light conditions for 24 hours. The results of Examples 33-37 show that the formaldehyde scavenging rate changes by changing the type and dosage of the second capture agent. Among them, Example 37 uses ethyl acetate, and the formaldehyde scavenging rate is the lowest, only 94.2%; Example 34 uses glycolic anhydride diacetate as the formaldehyde capture agent, and the dosage is controlled to be 11.8 parts, and the formaldehyde scavenging rate is the highest. Examples 38-41, by changing the type of capture agent three and the dosage of capture agent three in capture agent one, the formaldehyde scavenging rate of the obtained high-efficiency photocatalyst formaldehyde scavenger is 99.5%-99.9%; Example 41 uses epigallocatechin gallate as the capture agent three, the dosage is 45.9 parts, and it is grafted to carboxymethyl cellulose through diethylenetriamine, and the formaldehyde scavenging rate is the highest. In summary, the present invention achieves the capture and removal effect of formaldehyde by adding different types of capture agents.

[0089] Embodiment 43

[0090] The doped titanium dioxide was prepared using the parameters of Example 17; the photocatalyst was prepared using the parameters of Example 26; the capture agent was prepared using the parameters of Example 41;

[0091] 0.5 parts of pigment are dissolved in water, and then 7 parts of photocatalyst and 12 parts of capture agent are added thereto, and finally 1 part of dispersant stabilizer zinc stearate is added, and after stirring, ultrasonic homogenization is performed to obtain a high-efficiency photocatalyst formaldehyde scavenger; the total amount of each component of the high-efficiency photocatalyst formaldehyde scavenger is 100 parts.

[0092] Examples 44-54

[0093] Different from Example 43, the component dosage of the high-efficiency photocatalyst formaldehyde scavenger is changed, as shown in Table 7.

[0094] Table 7 Component dosage of high-efficiency photocatalyst formaldehyde scavenger

[0095]

[0096]

[0097] Embodiment 55

[0098] The high-efficiency photocatalyst formaldehyde scavengers prepared in Examples 43-54 and Comparative Examples 7-9 were tested for stability and formaldehyde removal rate. The formaldehyde removal rate method was carried out with reference to Example 14; after the high-efficiency photocatalyst formaldehyde scavenger was stored for 1 month, the formaldehyde removal rate was tested again. The smaller the formaldehyde removal rate reduction value under the light condition, the higher the formaldehyde removal rate, indicating that its stability is better. The final test results are shown in Table 8.

[0099] Table 8 Stability and formaldehyde removal results

[0100]

[0101] The high-efficiency photocatalyst formaldehyde scavenger prepared by the present invention is used after storage for 0 month, and the formaldehyde scavenging rate under illumination conditions is 73.1%-99.4%, and the formaldehyde scavenging rate after storage for 1 month is 64.6%-98.1%. In Examples 43-47, with the increase of the amount of photocatalyst, the formaldehyde scavenging rate after direct use shows a trend of first increasing, then decreasing, and then increasing. After storage for 1 month, the decrease value of the formaldehyde scavenging rate shows a decreasing trend. The formaldehyde scavenging rate decrease value of Example 47 is the smallest, which is 1.3%. The results of Examples 46-49 show that when the amount of the trapping agent is the highest, as shown in Example 49, the formaldehyde scavenging rate is the highest, and the formaldehyde scavenging rate decreases after storage for 1 month, and the scavenging rate is 97.5%. Without adding the trapping agent, the formaldehyde scavenging rate decreases, as shown in Comparative Example 7, the formaldehyde scavenging rates after storage for 0 month and 1 month are 73.1% and 64.6%, respectively. The results of Examples 47, 50, and 51 show that as the amount of pigment increases, the formaldehyde removal effect gradually increases. Comparative Example 8 does not add pigment, and the formaldehyde removal effect decreases. The results of Examples 51-54 show that as the amount of dispersion stabilizer increases, the formaldehyde removal rate does not change significantly after 0 month of storage, but after long-term storage and reuse, the formaldehyde removal rate decreases slightly. Comparative Example 9 does not add dispersion stabilizer, and the formaldehyde removal rate decreases by 11.3% after 1 month of storage.

[0102] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a highly efficient photocatalyst formaldehyde scavenger, characterized in that: The following steps are involved: Dissolve 0-0.7 parts of pigment in water, add 5.5-9 parts of photocatalyst, 0-14 parts of trapping agent and 0-3 parts of dispersion stabilizer, stir and homogenize by ultrasonication to obtain a high-efficiency photocatalyst formaldehyde scavenger; the trapping agent includes trapping agent 1, trapping agent 2 and trapping agent 3; The powder material is dispersed in anhydrous ethanol to obtain a powder liquid; the anhydrous ethanol, hydrochloric acid, water and 0-7.8 parts of the powder liquid are added to a tetrabutyl titanate solution, stirred for 30-48 hours, dried and ground into a gel powder; the gel powder is put into a tubular furnace, roasted at a roasting temperature of 400-550° C. for 2-7 hours, and cooled to obtain doped titanium dioxide; Add 1.2-2.0 parts of the doped titanium dioxide to a cobalt nitrate solution, stir, ultrasonicate, then add a polyacrylonitrile solution, stir to obtain a spinning solution; electrospin the spinning solution to obtain nano-doped titanium dioxide-cobalt fibers; dissolve 3.8-4.4 parts of 2-methylpyrazole and N,N-dimethylethylenediamine in the anhydrous ethanol to obtain a mixed solution; immerse the nano-doped titanium dioxide-cobalt fibers in the mixed solution, grow in situ for 22-30 hours, wash, dry, crush and grind, and obtain the photocatalyst; Disperse carboxymethyl cellulose in water, add 11.0-11.8 parts of diethylenetriamine and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride after heating, adjust the pH of the system to 3, and react to obtain a diethylenetriamine grafted cellulose solution; add 29.0-45.9 parts of the capture agent three to the diethylenetriamine grafted cellulose solution, adjust the pH to 10.5, stir the reaction, filter, wash, and dry to obtain the capture agent one.

2. The method for preparing a high-efficiency photocatalyst formaldehyde scavenger according to claim 1, characterized in that: The pigment is used in an amount of 0.3-0.7 parts; the capture agent is used in an amount of 10-14 parts.

3. The method for preparing a high-efficiency photocatalyst formaldehyde scavenger according to claim 1, characterized in that: The dispersion stabilizer is zinc stearate; the amount of zinc stearate is 1-3 parts.

4. The method for preparing a high-efficiency photocatalyst formaldehyde scavenger according to claim 1, characterized in that: The total amount of the pigment, the photocatalyst, the trapping agent and the dispersion stabilizer in the high-efficiency photocatalyst formaldehyde scavenger is 100 parts; the ratio of the first trapping agent, the second trapping agent and the third trapping agent is 1:3:

1.

5. The method for preparing a high-efficiency photocatalyst formaldehyde scavenger according to claim 1, characterized in that: The preparation method of the pigment is as follows: using gauze to wipe off the dirt on the surface of the spider plant, using scissors to avoid the main vein to sample the leaves, and obtaining square leaves with a side length of 0.5 cm; adding the square leaves into a mortar and grinding them to obtain leaf pulp; transferring the leaf pulp to an ethanol-water solution, ultrasonically stirring for 6 hours to obtain an extract; filtering the extract, and rotary evaporating to dryness to obtain the pigment; the ratio of ethanol to water in the ethanol-water solution is 19:

1.

6. The method for preparing a high-efficiency photocatalyst formaldehyde scavenger according to claim 1, characterized in that: The powder material includes component one and component two; the component one is one of tin telluride, lead telluride, lead selenide, mercury selenide, mercury telluride and indium antimonide; the component two is tungsten oxide; the powder material is a mixture of component one and component two in a ratio of 4:

1.

7. The method for preparing a high-efficiency photocatalyst formaldehyde scavenger according to claim 1, characterized in that: The powder liquid is used in an amount of 0.5-7.8 parts; the tetrabutyl titanate solution is obtained by dissolving tetrabutyl titanate in the anhydrous ethanol.

8. The method for preparing a high-efficiency photocatalyst formaldehyde scavenger according to claim 1, characterized in that: The calcination temperature is 400-500° C. and the calcination time is 2.5-7 hours.

9. The method for preparing a high-efficiency photocatalyst formaldehyde scavenger according to claim 1, characterized in that: The second capture agent is one of glycolic anhydride diacetate, methoxyacetic anhydride, ethoxy guaiacol acetate, and acetoethyl acetate; the third capture agent is one of quercetin, catechin, epicatechin gallate, and epigallocatechin gallate.

10. A highly efficient photocatalyst formaldehyde scavenger, characterized in that: The high-efficiency photocatalyst formaldehyde scavenger comprises a pigment, a photocatalyst, a capture agent 1, a capture agent 2, a capture agent 3, a dispersing stabilizer and water; the high-efficiency photocatalyst formaldehyde scavenger is obtained by the preparation method according to any one of claims 1 to 9; the preparation conditions of doped titanium dioxide are changed, and the formaldehyde removal rate of the high-efficiency photocatalyst formaldehyde scavenger in 24 hours under light conditions is 76.0%-99.8%, and the formaldehyde removal rate in 24 hours under dark conditions is 52.8%-95.6%; the formaldehyde removal rate of the high-efficiency photocatalyst formaldehyde scavenger in 0.5 hours under light conditions is 31.6%-57.1%, the formaldehyde removal rate in 8 hours is 68.0%-99.9%, and the formaldehyde removal rate in 24 hours is 77. 3%-99.9%; by changing the preparation conditions of the photocatalyst, the formaldehyde removal rate of the high-efficiency photocatalyst formaldehyde scavenger is 47.8%-58.2% in 0.5h, 85.9%-99.9% in 8h, and 91.3%-99.9% in 24h; by changing the preparation conditions of the capture agent, the formaldehyde removal rate of the high-efficiency photocatalyst formaldehyde scavenger under the illumination conditions is 94.7%-99.9% in 24h; by changing the dosage of the preparation components of the high-efficiency photocatalyst formaldehyde scavenger, the formaldehyde removal rate of the high-efficiency photocatalyst formaldehyde scavenger under the illumination conditions is 73.1%-99.4% in 0-month storage, and the formaldehyde removal rate of the high-efficiency photocatalyst formaldehyde scavenger under the illumination conditions is 64.6%-98.1% in 1-month storage.

Images