A gold nanoparticle / manganese oxide composite sub-micron macroporous fiber membrane and a preparation method thereof

Abstract

The application relates to a gold nanoparticle / manganese oxide composite submicron macroporous fiber membrane and a preparation method thereof. The submicron macroporous fiber membrane is characterized in that PMAA microspheres loaded with gold nanoparticles and manganese oxide nanoparticles are uniformly dispersed in an amino-modified polyvinyl butyral resin (PVB), the PMAA microspheres are etched by a template removal method, and a submicron fiber membrane with a uniform macroporous structure is obtained, which is applied to removal of formaldehyde in indoor air, and the formaldehyde removal rate can reach 92.6% within 1.5 hours, and the removal effect is good. The application has the characteristics of simple process, controllable operation, high porosity of the product, small pore size, large specific surface area and the like; and the submicron fiber membrane prepared by the application has a macroporous structure.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of gold nanoparticle / manganese oxide composite submicron macroporous fiber membrane and its preparation method, belong to transition metal oxide composite material technical field. BACKGROUND

[0002] In the existing formaldehyde removal technology, catalytic oxidation method is widely concerned due to mild reaction conditions, and product is CO2 and H2O without secondary pollution.Catalyst materials of catalytic oxidation method mainly include noble metal and excessive metal oxide catalyst system, supported noble metal catalyst has excellent formaldehyde room temperature catalytic activity, but its excessively high cost limits its wide application to some extent, manganese oxide (MnOx) catalyst is widely studied due to its excellent catalytic activity for formaldehyde oxidation, and can completely oxidize formaldehyde at lower temperature (about 100 DEG C), but the catalytic efficiency at room temperature still needs to be improved. SUMMARY

[0003] In view of the existing technical deficiencies, the technical problem to be solved by the present application is that gold nanoparticles are prone to agglomeration due to small particle size, difficult to be uniformly distributed, catalyst material has low porosity and small specific surface area, and cannot be fully contacted with air, so that the catalytic efficiency is difficult to improve, and the removal capacity of formaldehyde and VOCs in air is low.

[0004] To solve the above technical problems, the technical scheme provided by the present application is as follows:

[0005] The present application provides a kind of gold nanoparticle / manganese oxide composite submicron macroporous fiber membrane, the gold nanoparticle / manganese oxide composite fiber membrane is that gold nanoparticle and manganese oxide nanoparticles are supported in poly (methacrylic acid) (PMAA) microsphere is uniformly dispersed in amino modified polyvinyl butyral resin (PVB), PMAA microsphere is etched by template removal method, obtain the submicron macroporous fiber membrane with uniformly distributed macropore, gold nanoparticle and manganese oxide nanoparticles are uniformly distributed on macropore.It has the advantages of high porosity, small pore size, large specific surface area, large air contact area, etc.

[0006] The present application discloses the following technical effects:

[0007] (1) The Au / MnOx / mPVB sub-micron macroporous fiber membrane synthesized by the application has the characteristics of small pore size, high porosity and large specific surface area, the PMAA microspheres loaded with gold nanoparticles and manganese oxide nanoparticles are uniformly dispersed on the nanofiber, the PMAA microspheres are etched by using a template removal method, and a uniform macroporous fiber is obtained. The catalyst is uniformly loaded on the inner wall of the macropore, which improves the stability of the nanoparticles fixed on the carrier, and the fiber modified by the amino functional group has good formaldehyde adsorption performance, which forms a synergistic effect with catalysis, improves the catalytic degradation activity, and shows good catalytic performance for the removal of low-concentration formaldehyde in the indoor environment. The process preparation route of the application is simple, and the reaction conditions are mild.

[0008] (2) The Au / MnOx / mPVB sub-micron macroporous fiber membrane catalyst material synthesized by the application has good removal capacity for formaldehyde in the indoor environment. When the initial concentration is 0.8 ppm, the temperature is 25℃, and the relative humidity is 50%, the formaldehyde concentration can be reduced to below 0.08 ppm within 90 minutes, and after at least 6 consecutive cycles, the formaldehyde removal efficiency can still be positioned above 90%. The results show that the Au / MnOx / mPVB sub-micron macroporous fiber membrane has excellent formaldehyde catalytic activity and is a formaldehyde catalytic oxidation material with good application prospect.

[0009] (3) The reaction process of the application has strong controllability, and different properties can be obtained according to the needs by changing the reaction conditions, experimental variables. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 The transmission electron microscope image of the PMAA microspheres prepared in Examples 1-4 of the application;

[0011] Figure 2 The transmission electron microscope image of the Au@PMAA microspheres prepared in Examples 1-4 of the application;

[0012] Figures 3-6 The transmission electron microscope image of the Au / MnOx@PMAA microspheres prepared in Examples 1-4 of the application;

[0013] Figure 7 The transmission electron microscope image of the Au / MnOx@PMAA / mPVB composite fiber membrane prepared in Examples 1-4 of the application;

[0014] Figure 8 The transmission electron microscope image of the Au / MnOx / mPVB porous composite fiber membrane prepared in Examples 1-4 of the application;

[0015] Figure 9 The XRD spectrum of some samples prepared in Examples 1-4 and Comparative Examples 1-3 of the application;

[0016] Figures 10-11 Catalytic test spectrum of the composite fiber membrane sample prepared in the application; DETAILED DESCRIPTION

[0017] The specific embodiments of the application are given below. The specific embodiments are only used to further illustrate the application, and do not limit the protection scope of the claims of the application.

[0018] The application provides a gold nanoparticle manganese oxide composite submicron macroporous fiber membrane and a preparation method thereof (referred to as the method).

[0019] (1) Preparation of Au@PMAA composite microspheres

[0020] Monodisperse PMAA microspheres are prepared by distillation-precipitation polymerization with methacrylic acid (MAA) as a monomer and azobisisobutyronitrile (AIBN) as an initiator. Appropriate PMAA microspheres are taken into a round-bottom flask containing acetonitrile, stirred and mixed, and then HAuCl4 acetone solution is added. After stirring in the dark, NaBH4 aqueous solution is added, and then centrifugal washing is continued. The Au@PMAA composite microspheres are obtained by sealing and storing in appropriate acetonitrile in the dark.

[0021] (2) Preparation of Au / MnOx@PMAA microspheres

[0022] The Au@PMAA in step (1) is taken into a round-bottom flask containing appropriate acetonitrile, stirred and mixed, and then a certain amount of KMnO4 is added. After stirring in the dark, appropriate methanol is added, and then centrifugal washing is continued for 4 times. The Au / MnOx@PMAA microspheres are obtained by sealing and storing in appropriate acetonitrile in the dark.

[0023] (3) Preparation of amino-modified polyvinyl butyral resin (mPVB)

[0024] Amino-modified polyvinyl butyral resin (mPVB) is prepared by dehydration condensation with 3-aminopropyl triethoxysilane (ATPES) as a crosslinking agent. Appropriate polyvinyl butyral (PVB) is added to a mixed solution of ethanol and water, heated and stirred until completely dissolved, degassed and cooled to 30°C, and then a certain proportion of ATPES is added. After stirring, an aqueous HCl solution is added, and then excess ultrapure water is added. The PVB is precipitated, and the solid product is recovered by filtration, washed with ethanol for 2 times, and then the amino-modified polyvinyl butyral resin (mPVB) is obtained.

[0025] (4) Preparation of Au / MnOx@PMAA / mPVB composite fiber membrane

[0026] The Au / MnOx@PMAA / mPVB composite fiber membrane is prepared by electrospinning. The mPVB resin prepared in step 4) and the Au / MnOx@PMAA composite microspheres in step (3) are respectively ultrasonically dispersed in propyl formate, and an appropriate amount of N-hexyl pyridine hexafluorophosphate is added. After stirring to completely dissolve, the spinning solution is prepared. The spinning is carried out by setting the voltage, injection flow rate, receiving distance, temperature and other parameters on the spinning machine by using electrospinning technology, to prepare the Au / MnOx@PMAA / mPVB composite fiber membrane.

[0027] (5) Preparation of Au / MnOx / mPVB composite sub-micron macroporous fiber membrane

[0028] The porous composite fiber membrane Au / MnOx / mPVB is prepared by template removal method. The specific steps are as follows: a sodium hydroxide solution with pH=10 is prepared, the Au / MnOx@PMAA / mPVB composite fiber membrane is immersed in the sodium hydroxide solution, the PMAA microspheres are selectively removed to prepare a macroporous structure, the AuNPs are loaded on the inner pore wall of the fiber, and vacuum drying is performed to obtain the Au / MnOx / mPVB porous composite fiber membrane.

[0029] Further, the particle size of the PMAA microspheres in step (1) is between 160 nm and 190 nm, the polydispersity index PDI=1.008<1.05, and the dispersibility is good.

[0030] Further, the molar ratio of PMAA to Au in step (1) is 40:1.

[0031] Further, the amount-of-substance ratio of PMAA:Mn: Au in step (2) is 40:4:1, 40:8:1, 40:12:1 or 40:16:1.

[0032] Further, the mass fraction of APTES in step (3) is 10% to 50%, and the concentration of HCl is 2 mol / L.

[0033] Further, the mass fraction of the mPVB resin in step (4) is 12 wt%, the mass fraction of N-hexyl pyridine hexafluorophosphate is 1.5%, the spinning voltage is 8-10 kV, the injection speed is 0.06-0.1 mm / min, the receiving distance is 10-20 cm, and the temperature is 20-25°C.

[0034] Further, the mass fraction of Au / MnOx@PMAA in step (4) can be between 1 wt% and 5 wt%.

[0035] In the embodiment of the present application, the formaldehyde removal effect test analysis is as follows: under the condition of temperature 25℃ and relative humidity 50%, 0.1 g of prepared gold nanoparticle / manganese oxide composite sub-micron macroporous fiber membrane is weighed and fixed in a 0.18 m 3 The small airtight box in the formaldehyde static test experiment cabin is immediately closed, 5 μL of 37-40% formaldehyde solution diluted 2.5 times is injected by using a microsyringe, the formaldehyde concentration in the experiment cabin at different times is detected by using a PPM htv-m formaldehyde detector of PPM-technology company in the United Kingdom, and the formaldehyde removal rate is calculated. Formaldehyde removal rate = (C0-C t )*100% / C0(C0 is the initial concentration of formaldehyde, and C t is the concentration after formaldehyde reaction).

[0036] Morphology and structure characterization test method of composite sub-micron macroporous fiber membrane:

[0037] 1. Morphology test: the morphology structure of the product is observed by using a transmission electron microscope (TEM), and TEM images with magnifications of 200000x and 30000x are obtained.

[0038] 2. Structure characterization: the sample is analyzed and tested by using a Fourier transform infrared spectrometer, and the chemical composition and chemical structure of the sample are obtained.

[0039] 3. Structure characterization: the sample is analyzed and tested by using an XRD ray diffractometer, and the crystal face property and crystal form structure of the sample are obtained.

[0040] Catalytic test: the formaldehyde catalytic performance of the sample is tested by using a complete mixing batch mode static removal test device.

[0041] Example 1

[0042] (1) 2 mL of MAA and 0.04 g of AIBN are taken and dispersed into a 100 mL round-bottom flask containing 80 mL of acetonitrile. After ultrasonic mixing, three zeolites are added, and distillation is heated at a voltage of 80 V. The reaction boils within 15 min, and the color gradually changes from milky white to white within 30 min, and the first drop of solvent is evaporated. After 1 h of reaction, the heating is stopped when about 40 mL of acetonitrile is evaporated, and after cooling to room temperature, it is transferred to a centrifuge tube, the rotation speed is set to 11000 r / min, and centrifugation is performed for 15 min, and the supernatant is discarded. The solid sample is weighed. Disperse in an appropriate amount of acetonitrile, seal and dry, and obtain monodisperse polymer microspheres PMAA.

[0043] (2) Take 3 mL PMAA in step (1) into a 100 mL dry round bottom flask containing 70 mL acetonitrile, stir and mix well, then add 1 mL 0.02943 mol / L HAuCl4 acetone solution (molar ratio of PMAA: Au is 40:1), the solution changes from milky white to light yellow. After stirring at low speed for 12 h in the dark, increase the speed and quickly add 0.1 mL 0.2943 mol / L NaBH4 aqueous solution under the liquid surface (molar ratio of NaBH4: Au is 10:1), the solution changes from light yellow to brick red. Continue to stir in the dark for 6 h, then transfer to a centrifuge tube, centrifuge at 10000 r / min for 15 min, wash with acetonitrile for 4 times, disperse in a proper amount of acetonitrile, seal and store in the dark, and Au@PMAA composite microspheres are obtained.

[0044] (3) Take Au@PMAA in step (2) into a 100 mL round bottom flask containing 70 mL acetonitrile, stir and mix well, then add a certain amount of KMnO4 (molar ratio of PMAA: Mn: Au is 40:12:1), the solution changes from brick red to purple, stir at low speed for 1 h in the dark, then slowly add 0.9 mL methanol, the solution changes from purple to brown slowly. Continue to stir in the dark for 23 h, then transfer to a centrifuge tube, centrifuge at 10000 r / min for 15 min, wash with acetonitrile for 4 times, disperse in a proper amount of acetonitrile, seal and store in the dark, and Au / MnOx@PMAA composite microspheres are obtained.

[0045] (4) Add 2 g PVB into a mixed solution of 90 mL ethanol and 10 mL water, stir until completely dissolved at 80-90°C, stabilize for 1 h, then degas and cool to 30°C; add 10%, 20%, 30%, 40% and 50% of APTES based on the mass of PVB respectively, stir for 10 min, add 1 mL 2 mol / L HCL aqueous solution, continue to stir for 6 h; slowly add excess ultrapure water, precipitate PVB, filter the solid product, wash with ethanol for 2 times to remove unbound APTES, and obtain amino-modified polyvinyl butyral resin (mPVB).

[0046] (5) Take 0.738 g (12 wt%) of mPVB resin prepared in step (4) and 0.073 g (1.5 wt%) of N-hexylpyridine hexafluorophosphate into 6 mL propyl formate solution, stir until completely dissolved and no bubbles are generated. Take 2 wt% Au / MnOx@PMAA composite microspheres based on the mass into the above solution, stir uniformly. Place the mixed solution in an electrospinning machine, adjust the voltage to 9 kV, the injection speed to 0.09 mm / min, the receiving speed to 40 r / min, the receiving distance to 15 cm, the humidity to 50%, and the temperature to room temperature, and spin to obtain Au / MnOx@PMAA / mPVB composite fiber membrane.

[0047] (6) The Au / MnOx@PMAA / mPVB composite fiber membrane in step (5) is immersed in a sodium hydroxide solution (PH = 10) to selectively remove the PMAA microspheres, prepare a macroporous structure, load the AuNPs on the inner pore wall of the fiber, and dry under vacuum to obtain an Au / MnOx / mPVB porous composite fiber membrane.

[0048] Effect experiment:

[0049] The prepared gold nanoparticle / manganese oxide composite submicron macroporous fiber membrane is placed in the experimental cabin, and the formaldehyde removal rate is 92.6% after 1.5 hours, which can prove that the gold nanoparticle / manganese oxide composite submicron macroporous fiber membrane of the application can efficiently remove low-concentration formaldehyde in the air.

[0050] Example 2

[0051] (1) Take 2 mL of MAA and 0.04 g of AIBN, and disperse them into a 100 mL round-bottom flask containing 80 mL of acetonitrile. After ultrasonic mixing, add three zeolites, and heat and distill under a voltage of 80 V. The reaction boils within 15 min, and the color gradually changes from milky white to white within 30 min, and the first drop of solvent is evaporated. After 1 h of reaction, stop heating when about 40 mL of acetonitrile is evaporated, and cool to room temperature. Transfer to a centrifuge tube, set the speed to 11000 r / min, and centrifuge for 15 min. Discard the supernatant. Wash the solid sample with acetonitrile 4 times. Weigh the solid sample. Disperse in an appropriate amount of acetonitrile, seal and dry, and obtain monodisperse polymer microspheres PMAA.

[0052] (2) Take 3 mL of PMAA in step (1) and add it to a 100 mL dry round-bottom flask containing 70 mL of acetonitrile. Mix well, then add 1 mL of 0.02943 mol / L HAuCl4 acetone solution (molar ratio of PMAA:Au is 40:1). The solution changes from milky white to light yellow. After low-speed stirring in the dark for 12 h, increase the speed and quickly add 0.1 mL of 0.2943 mol / L NaBH4 aqueous solution under the liquid surface (molar ratio of NaBH4:Au is 10:1). The solution changes from light yellow to brick red. Continue to stir in the dark for 6 h, then transfer to a centrifuge tube, centrifuge at 10000 r / min for 15 min, wash with acetonitrile 4 times, disperse in an appropriate amount of acetonitrile, seal and store in the dark, and obtain Au@PMAA composite microspheres.

[0053] (3) Take the Au@PMAA from step (2) and add it to a 100mL round-bottom flask containing 70mL of acetonitrile. After stirring and mixing, add a certain amount of KMnO4 (the molar ratio of PMAA:Mn:Au is 40:4:1). The solution changes from brick red to purple. After stirring at low speed in the dark for 1 hour, slowly add 0.7mL of methanol. The solution slowly changes from purple to brown. Continue stirring in the dark for 23 hours. Transfer to a centrifuge tube and centrifuge at 10000r / min for 15min. Wash 4 times with acetonitrile and disperse in an appropriate amount of acetonitrile. Seal and store in the dark to obtain Au / MnOx@PMAA composite microspheres.

[0054] (4) Add 2g PVB to a mixed solution of 90mL ethanol and 10mL water, stir at 80-90℃ until completely dissolved, stabilize for 1h, degas and cool to 30℃; add 10%, 20%, 30%, 40% and 50% APTES by mass of PVB respectively, stir for 10min, add 1mL of 2mol / L HCl aqueous solution, and continue stirring for 6h; slowly add excess ultrapure water to precipitate PVB, filter to recover the solid product, wash twice with ethanol to remove unbonded APTES, and obtain amino-modified polyvinyl butyral resin (mPVB).

[0055] (5) Weigh 0.738 g (12 wt%) of the mPVB resin prepared in step (4) and 0.073 g (1.5 wt%) of N-hexylpyridine hexafluorophosphate, add them to 6 mL of propyl formate solution, and stir until completely dissolved and no bubbles are generated. Place the mixed solution in an electrospinning machine, adjust the voltage to 9 kV, the injection speed to 0.09 mm / min, the receiving speed to 40 r / min, the receiving distance to 15 cm, the humidity to 50%, and the temperature to room temperature, and spin to obtain Au / MnOx@PMAA / mPVB composite fiber membrane.

[0056] (6) The Au / MnOx@PMAA / mPVB composite fiber membrane from step (5) is immersed in sodium hydroxide solution (pH=10) to selectively remove PMAA microspheres and prepare a macroporous structure so that AuNPs are loaded on the inner pore wall of the fiber. The membrane is then dried under vacuum to obtain Au / MnOx / mPVB porous composite fiber membrane.

[0057] Effect Experiment:

[0058] The prepared gold nanoparticle / manganese oxide composite submicron macroporous fiber membrane was placed in the experimental chamber. After 1.5 hours, the formaldehyde removal rate was measured to be 71.3%, which proves that the gold nanoparticle / manganese oxide composite submicron macroporous fiber membrane of the present invention can efficiently remove low concentrations of formaldehyde from the air.

[0059] Example 3

[0060] (1) Take 2 mL of MAA, 0.04 g of AIBN, and disperse them into a 100 mL round-bottom flask containing 80 mL of acetonitrile. After ultrasonic mixing, add three zeolites, and heat and distill under a voltage of 80 V. The reaction boils within 15 min, and within 30 min, the solution gradually changes from milky white to white, and the first drop of solvent is distilled off. After 1 h of reaction, stop heating when about 40 mL of acetonitrile has been distilled off, and cool to room temperature. Then transfer to a centrifuge tube, set the rotation speed to 11,000 r / min, and centrifuge for 15 min. Discard the supernatant. Wash the solid sample with acetonitrile four times by centrifugation. Weigh the solid sample. Disperse it in an appropriate amount of acetonitrile, seal, and store to obtain monodisperse polymer microspheres PMAA.

[0061] (2) Take 3 mL of PMAA from step (1) and add it to a 100 mL dry round-bottom flask containing 70 mL of acetonitrile. After stirring and mixing, add 1 mL of 0.02943 mol / L HAuCl4 acetone solution (molar ratio of PMAA: Au is 40:1). The solution changes from milky white to light yellow. After low-speed stirring in the dark for 12 h, increase the rotation speed and quickly add 0.1 mL of 0.2943 mol / L NaBH4 aqueous solution under the liquid surface (molar ratio of NaBH4: Au is 10:1). The solution changes from light yellow to brick red. Continue to stir in the dark for 6 h, then transfer to a centrifuge tube, centrifuge at 10,000 r / min for 15 min, wash with acetonitrile four times, disperse in an appropriate amount of acetonitrile, seal, and store in the dark to obtain Au@PMAA composite microspheres.

[0062] (3) Take Au@PMAA from step (2) and add it to a 100 mL round-bottom flask containing 70 mL of acetonitrile. After stirring and mixing, add a certain amount of KMnO4 (molar ratio of PMAA: Mn: Au is 40:8:1). The solution changes from brick red to purple. After low-speed stirring in the dark for 1 h, slowly add 0.8 mL of methanol. The solution slowly changes from purple to brown. Continue to stir in the dark for 23 h, then transfer to a centrifuge tube, centrifuge at 10,000 r / min for 15 min, wash with acetonitrile four times, disperse in an appropriate amount of acetonitrile, seal, and store in the dark to obtain Au / MnOx@PMAA composite microspheres.

[0063] (4) Add 2 g of PVB to a mixture of 90 mL of ethanol and 10 mL of water, and stir at 80-90°C until completely dissolved. After stabilizing for 1 h, degas and cool to 30°C. Add 10%, 20%, 30%, 40%, and 50% of the mass of PVB of APTES, respectively, and stir for 10 min. Add 1 mL of 2 mol / L HCL aqueous solution, and continue to stir for 6 h. Slowly add excess ultrapure water, and precipitate PVB. Filter the solid product, wash with ethanol twice to remove unbound APTES, and obtain amino-modified polyvinyl butyral resin (mPVB).

[0064] (5) Weigh 0.738 g (12 wt%) of the mPVB resin prepared in step (4), 0.073 g (1.5 wt%) of N-hexylpyridine hexafluorophosphate, and add them to 6 mL of propyl formate solution, stir until completely dissolved, and no bubbles are generated. Weigh 1 wt% of Au / MnOx@PMAA composite microspheres and add them to the above solution, stir uniformly. Place the mixed solution in an electrospinning machine, adjust the voltage to 9 kV, the injection speed to 0.09 mm / min, the receiving speed to 40 r / min, the receiving distance to 15 cm, the humidity to 50%, and the temperature to room temperature, and spin to obtain Au / MnOx@PMAA / mPVB composite fiber membrane.

[0065] (6) Soak the Au / MnOx@PMAA / mPVB composite fiber membrane in step (5) in a sodium hydroxide solution (PH = 10), selectively remove the PMAA microspheres, prepare a macroporous structure, load the AuNPs on the inner pore wall of the fiber, and dry under vacuum conditions to obtain an Au / MnOx / mPVB porous composite fiber membrane.

[0066] Effect experiment:

[0067] Place the prepared gold nanoparticle / manganese oxide composite submicron macroporous fiber membrane in the experimental chamber, and measure the formaldehyde removal rate to be 84.5% after 1.5 h, which can prove that the gold nanoparticle / manganese oxide composite submicron macroporous fiber membrane of the present application can efficiently remove low-concentration formaldehyde in the air.

[0068] Example 4

[0069] (1) Take 2 mL of MAA and 0.04 g of AIBN, and disperse them in a 100 mL round-bottom flask containing 80 mL of acetonitrile. After ultrasonic mixing, add three zeolites, and heat and distill under a voltage of 80 V. The reaction boils within 15 min, and the color gradually changes from milky white to white within 30 min, and the first drop of solvent is evaporated. After 1 h of reaction, stop heating when about 40 mL of acetonitrile is evaporated, and cool to room temperature, then transfer to a centrifuge tube, set the rotation speed to 11000 r / min, and centrifuge for 15 min, then discard the supernatant. Wash the solid sample with acetonitrile 4 times. Weigh the solid sample. Disperse it in an appropriate amount of acetonitrile, seal and dry, and obtain monodisperse polymer microspheres PMAA.

[0070] (2) Take 3 mL PMAA in step (1) into a 100 mL dry round bottom flask containing 70 mL acetonitrile, stir and mix well, then add 1 mL 0.02943 mol / L HAuCl4 acetone solution (molar ratio of PMAA: Au is 40:1), the solution changes from milky white to light yellow. After stirring at low speed for 12 h in the dark, increase the stirring speed and quickly add 0.1 mL 0.2943 mol / L NaBH4 aqueous solution under the liquid surface (molar ratio of NaBH4: Au is 10:1), the solution changes from light yellow to brick red. Continue to stir in the dark for 6 h, then transfer to a centrifuge tube, centrifuge at 10000 r / min for 15 min, wash with acetonitrile for 4 times, disperse in a proper amount of acetonitrile, seal and store in the dark, and Au@PMAA composite microspheres are obtained.

[0071] (3) Take Au@PMAA in step (2) into a 100 mL round bottom flask containing 70 mL acetonitrile, stir and mix well, then add a certain amount of KMnO4 (molar ratio of PMAA: Mn: Au is 40:16:1), the solution changes from brick red to purple, stir at low speed for 1 h in the dark, then slowly add 1.0 mL methanol, the solution slowly changes from purple to brown. Continue to stir in the dark for 23 h, then transfer to a centrifuge tube, centrifuge at 10000 r / min for 15 min, wash with acetonitrile for 4 times, disperse in a proper amount of acetonitrile, seal and store in the dark, and Au / MnOx@PMAA composite microspheres are obtained.

[0072] (4) Add 2 g PVB into a mixed solution of 90 mL ethanol and 10 mL water, stir until completely dissolved at 80-90°C, stabilize for 1 h, then degas and cool to 30°C; add 10%, 20%, 30%, 40% and 50% of APTES based on the mass of PVB respectively, stir for 10 min, add 1 mL 2 mol / L HCL aqueous solution, continue to stir for 6 h; slowly add excess ultrapure water, precipitate PVB, filter the solid product, wash with ethanol for 2 times to remove unbound APTES, and obtain amino-modified polyvinyl butyral resin (mPVB).

[0073] (5) Take 0.738 g (12 wt%) of mPVB resin prepared in step (4) and 0.073 g (1.5 wt%) of N-hexylpyridine hexafluorophosphate into 6 mL propyl formate solution, stir until completely dissolved and no bubbles are generated. Take 3 wt% Au / MnOx@PMAA composite microspheres into the above solution and stir uniformly. Place the mixed solution in an electrospinning machine, adjust the voltage to 9 kV, the injection speed to 0.09 mm / min, the receiving speed to 40 r / min, the receiving distance to 15 cm, the humidity to 50%, and the temperature to room temperature, and spin to obtain Au / MnOx@PMAA / mPVB composite fiber membrane.

[0074] (6) Soaking the Au / MnOx@PMAA / mPVB composite fiber membrane in step (5) in a sodium hydroxide solution (PH = 10), selectively removing the PMAA microspheres, preparing a macroporous structure, loading the AuNPs on the inner pore wall of the fiber, and drying under vacuum to obtain an Au / MnOx / mPVB porous composite fiber membrane.

[0075] Effect experiment:

[0076] The prepared gold nanoparticle / manganese oxide composite submicron macroporous fiber membrane is placed in the experimental chamber, and the formaldehyde removal rate is 87.3% after 1.5 hours, which can prove that the gold nanoparticle / manganese oxide composite submicron macroporous fiber membrane of the present application can efficiently remove low-concentration formaldehyde in the air.

[0077] Example 5

[0078] (1) Take 2 mL of MAA and 0.04 g of AIBN, and disperse them in a 100 mL round-bottom flask containing 80 mL of acetonitrile. After ultrasonic mixing, add three zeolites, and heat and distill under a voltage of 80V. The reaction boils within 15 minutes, and the color gradually changes from milky white to white within 30 minutes, and the first drop of solvent is evaporated. After 1 hour of reaction, stop heating when about 40 mL of acetonitrile is evaporated, and cool to room temperature. Transfer to a centrifuge tube, set the speed to 11000 r / min, and centrifuge for 15 minutes. Discard the supernatant. Wash the solid sample with acetonitrile 4 times. Weigh the solid sample. Disperse in an appropriate amount of acetonitrile, seal and dry, and obtain monodisperse polymer microspheres PMAA.

[0079] (2) Take 3 mL of PMAA in step (1) and add it to a 100 mL dry round-bottom flask containing 70 mL of acetonitrile. Mix well, then add 1 mL of 0.02943 mol / L HAuCl4 acetone solution (molar ratio of PMAA to Au is 40:1). The solution changes from milky white to light yellow. After low-speed stirring in the dark for 12 hours, increase the speed and quickly add 0.1 mL of 0.2943 mol / L NaBH4 aqueous solution under the liquid surface (molar ratio of NaBH4 to Au is 10:1). The solution changes from light yellow to brick red. Continue to stir in the dark for 6 hours, then transfer to a centrifuge tube, centrifuge at 10000 r / min for 15 minutes, wash with acetonitrile 4 times, disperse in an appropriate amount of acetonitrile, seal and store in the dark, and obtain Au@PMAA composite microspheres.

[0080] (3) Take the Au@PMAA in step (2) into a 100 mL round-bottom flask containing 70 mL of acetonitrile, stir and mix well, then add a certain amount of KMnO4 (the molar ratio of PMAA:Mn: Au is 40:16:1), the solution changes from brick red to purple, stir at low speed in the dark for 1 h, then slowly add 1.0 mL of methanol, the solution slowly changes from purple to brown. Continue to stir in the dark for 23 h, then transfer to a centrifuge tube, centrifuge at 10,000 r / min for 15 min, wash with acetonitrile 4 times, disperse in a proper amount of acetonitrile, seal and store in the dark, and Au / MnOx@PMAA composite microspheres are obtained.

[0081] (4) 2 g of PVB is added to a mixed solution of 90 mL of ethanol and 10 mL of water, and stirred at 80-90°C until completely dissolved. After stabilizing for 1 h, degas and cool to 30°C; 10%, 20%, 30%, 40% and 50% of the mass of APTES is added respectively, stirred for 10 min, 1 mL of 2 mol / L HCL aqueous solution is added, and stirring is continued for 6 h; an excess of ultrapure water is slowly added, PVB is precipitated, the solid product is recovered by filtration, washed with ethanol twice to remove unbound APTES, and an amino-modified polyvinyl butyral resin (mPVB) is obtained.

[0082] (5) 0.738 g (12 wt%) of the mPVB resin prepared in step (4) and 0.073 g (1.5 wt%) of N-hexylpyridine hexafluorophosphate are weighed and added to 6 mL of propyl formate solution, and stirred until completely dissolved without generating bubbles. Au / MnOx@PMAA composite microspheres with a mass fraction of 5 wt% are weighed and added to the above solution, and stirred uniformly. The mixed solution is placed in an electrospinning machine, the voltage is adjusted to 9 kV, the injection speed is 0.09 mm / min, the receiving speed is 40 r / min, the receiving distance is 15 cm, the humidity is 50%, and the temperature is room temperature, and Au / MnOx@PMAA / mPVB composite fiber membrane is spun.

[0083] (6) The Au / MnOx@PMAA / mPVB composite fiber membrane in step (5) is soaked in a sodium hydroxide solution (PH = 10) to selectively remove the PMAA microspheres, prepare a macroporous structure, and load the AuNPs on the inner pore wall of the fiber, and a Au / MnOx / mPVB porous composite fiber membrane is obtained after drying under vacuum conditions.

[0084] Effect experiment:

[0085] The prepared gold nanoparticle / manganese oxide composite submicron macroporous fiber membrane is placed in the experimental cabin, and the formaldehyde removal rate is 79.6% after 1.5 h, which can prove that the gold nanoparticle / manganese oxide composite submicron macroporous fiber membrane of the application can efficiently remove low-concentration formaldehyde in the air.

[0086] Comparative Example 1

[0087] (1) Take 2 mL of MAA, 0.04 g of AIBN, and disperse into a 100 mL round-bottom flask containing 80 mL of acetonitrile. After ultrasonic mixing, add three zeolites, and heat distillation at a voltage of 80 V. The reaction boils within 15 min, and gradually changes from milky white to white within 30 min, and the first drop of solvent is evaporated. After 1 h of reaction, stop heating when about 40 mL of acetonitrile is evaporated, and cool to room temperature, then transfer to a centrifuge tube, set the speed to 11000 r / min, centrifuge for 15 min, and discard the supernatant. Wash with acetonitrile for 4 times. Weigh the solid sample. Disperse in an appropriate amount of acetonitrile, seal and store dry, to obtain monodisperse polymer microspheres PMAA.

[0088] (2) Take 3 mL of PMAA in step (1) and add to a 100 mL dry round-bottom flask containing 70 mL of acetonitrile, mix well after stirring, then add 1 mL of 0.02943 mol / L HAuCl4 acetone solution (molar ratio of PMAA: Au is 40:1), the solution changes from milky white to light yellow. After low-speed stirring in the dark for 12 h, increase the speed, and quickly add 0.1 mL of 0.2943 mol / L NaBH4 aqueous solution under the liquid surface (molar ratio of NaBH4: Au is 10:1), the solution changes from light yellow to brick red. Continue to stir in the dark for 6 h, then transfer to a centrifuge tube, centrifuge at 10000 r / min for 15 min, wash with acetonitrile for 4 times, disperse in an appropriate amount of acetonitrile, seal and store in the dark, to obtain Au@PMAA composite microspheres.

[0089] (3) Take Au@PMAA in step (2) and add to a 100 mL round-bottom flask containing 70 mL of acetonitrile, mix well after stirring, then add a certain amount of KMnO4 (molar ratio of PMAA: Mn: Au is 40:8:1), the solution changes from brick red to purple, low-speed stirring in the dark for 1 h, then slowly add 0.8 mL of methanol, the solution changes from purple to brown slowly. Continue to stir in the dark for 23 h, then transfer to a centrifuge tube, centrifuge at 10000 r / min for 15 min, wash with acetonitrile for 4 times, disperse in an appropriate amount of acetonitrile, seal and store in the dark, to obtain Au / MnOx@PMAA composite microspheres.

[0090] (4) 2 g PVB was added into a mixed solution of 90 mL ethanol and 10 mL water, and stirred at 80-90 °C until completely dissolved, and then degassed and cooled to 30 °C after being stabilized for 1 h; 10%, 20%, 30%, 40% and 50% of the mass of PVB of APTES was added respectively, and stirred for 10 min, 1 mL of 2 mol / L HCL aqueous solution was added, and stirring was continued for 6 h; an excess of ultrapure water was slowly added, and PVB was precipitated, and the solid product was recovered by filtration, washed twice with ethanol to remove unbound APTES, and an amino-modified polyvinyl butylal resin (mPVB) was obtained.

[0091] (5) 0.738 g (12 wt%) of the mPVB resin prepared in step (4) and 0.073 g (1.5 wt%) of N-hexylpyridine hexafluorophosphate were weighed and added to 6 mL of propyl formate solution, and stirred until completely dissolved without generating bubbles. Au / MnOx@PMAA composite microspheres with a mass fraction of 1 wt% were weighed and added to the above solution and stirred uniformly. The mixed solution was placed in an electrospinning machine, the voltage was adjusted to 9 kV, the injection speed was 0.09 mm / min, the receiving speed was 40 r / min, the receiving distance was 15 cm, the humidity was 50%, and the temperature was room temperature, and the Au / MnOx@PMAA / mPVB composite fiber membrane was spun.

[0092] Effect experiment:

[0093] The prepared Au / MnOx@PMAA / mPVB composite fiber membrane was placed in the experimental cabin, and the formaldehyde removal rate was 76.5% after 1.5 h, which proved that the gold nanoparticle / manganese oxide composite submicron macroporous fiber membrane with a large pore structure after etching could efficiently remove low-concentration formaldehyde in the air compared with the fiber membrane without etching.

[0094] Comparative example 2

[0095] (1) 2 mL of MAA and 0.04 g of AIBN were taken and dispersed in a 100 mL round-bottom flask containing 80 mL of acetonitrile. After ultrasonic mixing, three zeolites were added, and distillation was carried out under a voltage of 80 V. The reaction boiled within 15 min, and the color gradually changed from milky white to white within 30 min, and the first drop of solvent was evaporated. After 1 h of reaction, the heating was stopped when about 40 mL of acetonitrile was evaporated, and after cooling to room temperature, it was transferred to a centrifuge tube with a rotation speed of 11000 r / min, and centrifuged for 15 min, and the supernatant was discarded. The solid sample was weighed and dispersed in an appropriate amount of acetonitrile, sealed and dried to obtain monodisperse polymer microspheres PMAA.

[0096] (2) Take 3 mL PMAA in step (1) into a 100 mL dry round bottom flask containing 70 mL acetonitrile, stir and mix, then add 1 mL 0.02943 mol / L HAuCl4 acetone solution (molar ratio of PMAA: Au is 40:1), the solution changes from milky white to light yellow. After stirring at low speed for 12 h in the dark, increase the speed and quickly add 0.1 mL 0.2943 mol / L NaBH4 aqueous solution under the liquid surface (molar ratio of NaBH4: Au is 10:1), the solution changes from light yellow to brick red. Continue to stir in the dark for 6 h, then transfer to a centrifuge tube, centrifuge at 10000 r / min for 15 min, wash with acetonitrile for 4 times, disperse in a proper amount of acetonitrile, seal and store in the dark, and Au@PMAA composite microspheres are obtained.

[0097] (3) Take Au@PMAA in step (2) into a 100 mL round bottom flask containing 70 mL acetonitrile, stir and mix, then add a certain amount of KMnO4 (molar ratio of PMAA: Mn: Au is 40:12:1), the solution changes from brick red to purple, stir at low speed for 1 h in the dark, then slowly add 0.9 mL methanol, the solution changes from purple to brown slowly. Continue to stir in the dark for 23 h, then transfer to a centrifuge tube, centrifuge at 10000 r / min for 15 min, wash with acetonitrile for 4 times, disperse in a proper amount of acetonitrile, seal and store in the dark, and Au / MnOx@PMAA composite microspheres are obtained.

[0098] (4) Add 2 g PVB into a mixed solution of 90 mL ethanol and 10 mL water, stir until completely dissolved at 80-90°C, stabilize for 1 h, then degas and cool to 30°C; add 10%, 20%, 30%, 40% and 50% of APTES based on the mass of PVB respectively, stir for 10 min, add 1 mL 2 mol / L HCL aqueous solution, continue to stir for 6 h; slowly add excess ultrapure water, precipitate PVB, filter the solid product, wash with ethanol for 2 times to remove unbound APTES, and obtain amino-modified polyvinyl butyral resin (mPVB).

[0099] (5) Take 0.738 g (12 wt%) of mPVB resin prepared in step (4) and 0.073 g (1.5 wt%) of N-hexylpyridine hexafluorophosphate into 6 mL propyl formate solution, stir until completely dissolved and no bubbles are generated. Take 2 wt% Au / MnOx@PMAA composite microspheres based on the mass into the above solution, stir uniformly. Place the mixed solution in an electrospinning machine, adjust the voltage to 9 kV, the injection speed to 0.09 mm / min, the receiving speed to 40 r / min, the receiving distance to 15 cm, the humidity to 50%, and the temperature to room temperature, and spin to obtain Au / MnOx@PMAA / mPVB composite fiber membrane.

[0100] Effect experiment:

[0101] The prepared Au / MnOx@PMAA / mPVB composite fiber membrane is placed in the experimental cabin, and the formaldehyde removal rate is 81.2% after 1.5 hours, which can prove that the gold nanoparticle / manganese oxide composite submicron macroporous fiber membrane with large pore structure after etching in the application can efficiently remove low-concentration formaldehyde in the air compared with the fiber membrane without etching.

[0102] Comparative example 3

[0103] (1) Take 2 mL of MAA and 0.04 g of AIBN, and disperse them into a 100 mL round-bottom flask containing 80 mL of acetonitrile. After ultrasonic mixing, add three zeolites, and heat and distill under a voltage of 80 V. The reaction boils within 15 min, and the solution gradually changes from milky white to white within 30 min, and the first drop of solvent is evaporated. After 1 h of reaction, stop heating when about 40 mL of acetonitrile is evaporated, and cool to room temperature. Then transfer to a centrifuge tube, set the rotation speed to 11000 r / min, and centrifuge for 15 min. Discard the supernatant. Wash the solid sample with acetonitrile for 4 times. Weigh the solid sample. Disperse it in an appropriate amount of acetonitrile, seal and dry, and obtain monodisperse polymer microspheres PMAA.

[0104] (2) Take 3 mL of PMAA in step (1) and add it to a 100 mL dry round-bottom flask containing 70 mL of acetonitrile. After stirring and mixing, add 1 mL of 0.02943 mol / L HAuCl4 acetone solution (molar ratio of PMAA:Au is 40:1), and the solution changes from milky white to light yellow. After low-speed stirring in the dark for 12 h, increase the rotation speed and quickly add 0.1 mL of 0.2943 mol / L NaBH4 aqueous solution under the liquid surface (molar ratio of NaBH4:Au is 10:1), and the solution changes from light yellow to brick red. Continue to stir in the dark for 6 h, then transfer to a centrifuge tube, centrifuge at 10000 r / min for 15 min, wash with acetonitrile for 4 times, disperse in an appropriate amount of acetonitrile, seal and store in the dark, and obtain Au@PMAA composite microspheres.

[0105] (3) Take Au@PMAA in step 2) and add it to a 100 mL round-bottom flask containing 70 mL of acetonitrile. After stirring and mixing, add a certain amount of KMnO4 (molar ratio of PMAA:Mn:Au is 40:16:1), and the solution changes from brick red to purple. After low-speed stirring in the dark for 1 h, slowly add 1.0 mL of methanol, and the solution slowly changes from purple to brown. Continue to stir in the dark for 23 h, then transfer to a centrifuge tube, centrifuge at 10000 r / min for 15 min, wash with acetonitrile for 4 times, disperse in an appropriate amount of acetonitrile, seal and store in the dark, and obtain Au / MnOx@PMAA composite microspheres.

[0106] (4) 2 g PVB was added into a mixed solution of 90 mL ethanol and 10 mL water, and stirred at 80-90 °C until completely dissolved, and then degassed and cooled to 30 °C after being stabilized for 1 h; 10%, 20%, 30%, 40% and 50% of the mass of PVB of APTES was added respectively, and stirred for 10 min, 1 mL of 2 mol / L HCL aqueous solution was added, and stirring was continued for 6 h; an excess of ultrapure water was slowly added, and PVB was precipitated, and the solid product was recovered by filtration, washed twice with ethanol to remove unbound APTES, and an amino-modified polyvinyl butylal resin (mPVB) was obtained.

[0107] (5) 0.738 g (12 wt%) of the mPVB resin prepared in step (4) and 0.073 g (1.5 wt%) of N-hexylpyridine hexafluorophosphate were weighed and added to 6 mL of propyl formate solution, and stirred until completely dissolved without generating bubbles. 3 wt% of Au / MnOx@PMAA composite microspheres were weighed and added to the above solution and stirred uniformly. The mixed solution was placed in an electrospinning machine, the voltage was adjusted to 9 kV, the injection speed was 0.09 mm / min, the receiving speed was 40 r / min, the receiving distance was 15 cm, the humidity was 50%, and the temperature was room temperature, and the Au / MnOx@PMAA / mPVB composite fiber membrane was spun.

[0108] Effect experiment:

[0109] The prepared Au / MnOx@PMAA / mPVB composite fiber membrane was placed in the experimental cabin, and the formaldehyde removal rate was 79.4% after 1.5 h, which proved that the gold nanoparticle / manganese oxide composite submicron macroporous fiber membrane with macroporous structure after etching of the application could efficiently remove low-concentration formaldehyde in the air compared with the fiber membrane without etching.

[0110] Comparative example 4

[0111] (1) 2 mL of MAA and 0.04 g of AIBN were taken and dispersed in a 100 mL round-bottom flask containing 80 mL of acetonitrile. After ultrasonic mixing, three zeolites were added, and distillation was carried out under a voltage of 80 V. The reaction boiled within 15 min, and the color gradually changed from milky white to white within 30 min, and the first drop of solvent was evaporated. After 1 h of reaction, the heating was stopped when about 40 mL of acetonitrile was evaporated, and after cooling to room temperature, it was transferred to a centrifuge tube with a rotation speed of 11000 r / min, and centrifuged for 15 min, and the supernatant was discarded. The solid sample was weighed and dispersed in an appropriate amount of acetonitrile, sealed and dried to obtain monodisperse polymer microspheres PMAA.

[0112] (2) Take 3 mL of PMAA in step (1) into a 100 mL dry round-bottom flask containing 70 mL of acetonitrile, stir and mix, then add 1 mL of 0.02943 mol / L HAuCl4 acetone solution (molar ratio of PMAA: Au is 40:1), the solution changes from milky white to light yellow. After stirring at low speed in the dark for 12 h, increase the speed and quickly add 0.1 mL of 0.2943 mol / L NaBH4 aqueous solution under the liquid surface (molar ratio of NaBH4: Au is 10:1), the solution changes from light yellow to brick red. Continue to stir in the dark for 6 h, then transfer to a centrifuge tube, centrifuge at 10000 r / min for 15 min, wash with acetonitrile 4 times, disperse in an appropriate amount of acetonitrile, seal and store in the dark, and obtain Au@PMAA composite microspheres.

[0113] (3) Take the Au@PMAA in step (2) into a 100 mL round-bottom flask containing 70 mL of acetonitrile, stir and mix, then add a certain amount of KMnO4 (molar ratio of PMAA: Mn: Au is 40:16:1), the solution changes from brick red to purple, stir at low speed in the dark for 1 h, then slowly add 1.0 mL of methanol, the solution slowly changes from purple to brown. Continue to stir in the dark for 23 h, then transfer to a centrifuge tube, centrifuge at 10000 r / min for 15 min, wash with acetonitrile 4 times, disperse in an appropriate amount of acetonitrile, seal and store in the dark, and obtain Au / MnOx@PMAA composite microspheres.

[0114] (4) Add 2 g of PVB into a mixed solution of 90 mL of ethanol and 10 mL of water, stir until completely dissolved at 80-90°C, stabilize for 1 h, then degas and cool to 30°C; add 10%, 20%, 30%, 40% and 50% of APTES based on the mass of PVB respectively, stir for 10 min, add 1 mL of 2 mol / L HCL aqueous solution, continue to stir for 6 h; slowly add excess ultrapure water, precipitate PVB, filter the solid product, wash with ethanol 2 times to remove unbound APTES, and obtain amino-modified polyvinyl butyral resin (mPVB).

[0115] (5) Take 0.738 g (12 wt%) of mPVB resin prepared in step (4) and 0.073 g (1.5 wt%) of N-hexylpyridine hexafluorophosphate into 6 mL of propyl formate solution, stir until completely dissolved and no bubbles are generated. Take 5 wt% of Au / MnOx@PMAA composite microspheres based on the mass into the above solution, stir uniformly. Place the mixed solution in an electrospinning machine, adjust the voltage to 9 kV, the injection speed to 0.09 mm / min, the receiving speed to 40 r / min, the receiving distance to 15 cm, the humidity to 50%, and the temperature to room temperature, and spin to obtain Au / MnOx@PMAA / mPVB composite fiber membrane.

[0116] Effect experiment:

[0117] The prepared Au / MnOx@PMAA / mPVB composite fiber membrane is placed in the experimental cabin, and the formaldehyde removal rate is 74.0% after 1.5 hours, which proves that the gold nanoparticle / manganese oxide composite submicron macroporous fiber membrane with large pore structure after etching in the application can efficiently remove low-concentration formaldehyde in the air compared with the fiber membrane without etching.

[0118] By Figure 1 It can be seen that the prepared PMAA microspheres have smooth edges, regular shape, uniform size, clear boundaries, and an average particle size of about 175 nm, and are well dispersed.

[0119] By Figure 2 It can be seen that the prepared Au@PMAA composite microspheres still maintain good dispersibility, uniform size, and complete structure, and the AuNPs are uniformly distributed and well loaded, without aggregation.

[0120] By Figures 3-6 It can be seen that as the content of manganese oxide increases, the light transmittance of the composite microsphere surface gradually decreases, the thickness of the manganese oxide layer gradually increases, and the Au NPs are gradually obscured by the manganese oxide layer and become less obvious. In the two-dimensional image, the microspheres are uniformly distributed, the edges are rough, and they are similar to spherical particles.

[0121] By Figure 7 It can be seen that the Au / MnOx@PMAA composite microspheres are successfully electrospun into mPVB fibers, and are uniformly dispersed in the fiber interior. The composite fiber appears spherical protrusions, and the two-dimensional morphology of the Au / MnOx@PMAA composite microspheres is clearly visible in the fiber interior.

[0122] By Figure 8 It can be seen that after etching the PMAA microspheres, the macroporous structure appears in the electrospun fiber interior, and the Au / MnOx nanoparticles are retained in the fiber interior without falling off.

[0123] By Figure 9 It can be seen that the XRD spectrum of the sample is basically consistent with the diffraction peak position in the standard card, which proves that the prepared Au / MnOx@PMAA composite microspheres have both Au and δ-MnOx crystal faces.

[0124] By Figures 10-11 It can be seen that the removal efficiency of the prepared Au / MnOx / mPVB composite fiber membrane for formaldehyde can reach 92.6%, and after repeated experiments (6 times), the removal efficiency is still above 90%.

[0125] The unmentioned parts of the application are applicable to the prior art.

Claims

1. A gold nanoparticle / manganese oxide composite sub-micrometer macroporous fiber membrane, characterized in that, The sub-micron fiber membrane is prepared by electrospinning after blending of the amino-modified polyvinyl butyral as the fiber main body and the polymer microspheres (Au / MnOx@PMAA) loaded with gold nanoparticles and manganese oxide particles, and the macroporous structure of the sub-micron fiber membrane is formed by selective removal of the polymethyl methacrylate (PMAA) microspheres by a template removal method, and the prepared gold nanoparticle / manganese oxide composite sub-micron fiber membrane is used for purifying formaldehyde in indoor air; the preparation method comprises the following steps: (1) preparation of the polymethyl methacrylate composite microspheres (Au@PMAA) loaded with gold nanoparticles The monodisperse polymethyl methacrylate (PMAA) microspheres are prepared by distillation-precipitation polymerization with methyl methacrylate (MAA) as a monomer and azobisisobutyronitrile (AIBN) as an initiator, a proper amount of the polymethyl methacrylate (PMAA) microspheres are added into a round-bottom flask containing acetonitrile, stirred and mixed uniformly, then HAuCl4 acetone solution is added, NaBH4 aqueous solution is added after stirring in the dark, centrifugal washing is continued, and the polymethyl methacrylate composite microspheres (Au@PMAA) loaded with gold nanoparticles are obtained by sealing and storing in acetonitrile in the dark; (2) preparation of the polymer microspheres (Au / MnOx@PMAA) loaded with gold nanoparticles and manganese oxide particles The polymethyl methacrylate composite microspheres (Au@PMAA) loaded with gold nanoparticles in step (1) are added into a round-bottom flask containing a proper amount of acetonitrile, stirred and mixed uniformly, then a certain amount of KMnO4 is added, methanol is added after continued stirring in the dark, the mixture is transferred to a centrifugal tube after continued stirring in the dark, centrifugal washing is carried out for 4 times, and the polymer microspheres (Au / MnOx@PMAA) loaded with gold nanoparticles and manganese oxide particles are obtained by sealing and storing in acetonitrile in the dark, wherein the molar ratio of PMAA:Mn: Au is one of 40:4:1, 40:8:1, 40:12:1 and 40:16:1; (3) preparation of the amino-modified polyvinyl butyral resin (mPVB) A proper amount of polyvinyl butyral (PVB) is added into a mixed solution of ethanol and water, heated and stirred until completely dissolved, degassed and cooled to 30℃, a certain proportion of 3-aminopropyl triethoxysilane (ATPES) is added, stirred, HCl aqueous solution is added, continued stirring is carried out, and excess ultrapure water is added, and the polyvinyl butyral (PVB) is precipitated, the solid product is recovered by filtration, washed with ethanol for 2 times, and the amino-modified polyvinyl butyral resin (mPVB) is obtained; (4) preparation of the amino-modified polyvinyl butyral composite fiber membrane (Au / MnOx@PMAA / mPVB) blended with the polymer microspheres loaded with gold nanoparticles and manganese oxide particles The preparation of the Au / MnOx@PMAA / mPVB composite fiber membrane is as follows: a proper amount of the amino-modified polyvinyl butyral resin prepared in step (4) and the Au / MnOx@PMAA polymer microspheres loaded with gold nanoparticles and manganese oxide particles in step (2) are respectively ultrasonically dispersed in propyl formate, and a proper amount of N-hexylpyridine hexafluorophosphate is added to each of the dispersions, which are then mixed after stirring until completely dissolved to prepare a spinning solution; the Au / MnOx@PMAA / mPVB composite fiber membrane is prepared by electrospinning on a spinning machine with the following parameters: voltage, injection flow rate, receiving distance and temperature; and the mass fraction of the Au / MnOx@PMAA polymer microspheres loaded with gold nanoparticles and manganese oxide particles is between 1wt% and 5wt%. (5) Preparation of Au / MnOx composite sub-micron macroporous fiber membrane (Au / MnOx / mPVB) The Au / MnOx composite sub-micron macroporous fiber membrane (Au / MnOx / mPVB) is prepared by a template removal method, and the specific steps are as follows: a sodium hydroxide solution with a pH of 10 is prepared, and the Au / MnOx@PMAA / mPVB composite fiber membrane is immersed in the sodium hydroxide solution to selectively remove the PMAA microspheres, thereby preparing a macroporous structure and loading the Au nanoparticles (AuNPs) on the inner pore wall of the fiber, and vacuum drying to obtain the Au / MnOx composite sub-micron macroporous fiber membrane (Au / MnOx / mPVB).

2. The gold nanoparticle / manganese oxide composite sub-micrometer macroporous fiber membrane according to claim 1, characterized in that, In step (3), the amino-modified polyvinyl butyral is prepared by dehydration condensation of polyvinyl butyral (PVB) monomers and a crosslinking agent 3-aminopropyl triethoxysilane (ATPES). 3.The gold nanoparticle / manganese oxide composite sub-micrometer macroporous fiber membrane according to claim 1, characterized in that, In step (1), the particle size of the PMAA microspheres is between 160 nm and 190 nm, and the polydispersity index PDI is 1.008<1.

05.

4. The gold nanoparticle / manganese oxide composite sub-micrometer macroporous fiber membrane according to claim 1, characterized in that, In step (1), the molar ratio of PMAA to Au is 40:

1.

5. The gold nanoparticle / manganese oxide composite sub-micrometer macroporous fiber membrane according to claim 1, characterized in that, In step (4), the mass fraction of the 3-aminopropyl triethoxysilane (ATPES) is 10% to 50%, and the concentration of HCl is 2 mol / L.

Images