Activated carbon fiber capable of efficiently removing formaldehyde and preparation method of activated carbon fiber

Abstract

The invention provides an activated carbon fiber capable of efficiently removing formaldehyde and a preparation method thereof, the activated carbon fiber is of a composite material fiber structure of porous TiO2 derived from activated carbon and a metal organic framework (MOF), and the preparation method of the composite material comprises pretreatment of activated carbon, preparation of a Ti-MOF precursor and preparation of TiO2 / activated carbon fiber. According to the invention, the MOF-derived porous TiO2 / activated carbon composite fiber structure is constructed, physical adsorption and photocatalytic degradation functions are cooperated, and the limitation of single adsorption capacity is broken through; the interface bonding problem of the MOF derivative and the activated carbon is solved, and high-dispersion loading and stable and firm compounding of the active components are realized; a process path capable of realizing large-scale preparation is provided, and continuous production of the composite fiber is realized through an electrostatic spinning technology.

Description

Technical Field

[0001] The present invention relates to the technical field of activated carbon materials, and in particular to a functionalized activated carbon fiber material for efficiently removing formaldehyde and a preparation method thereof, and is particularly suitable for the treatment of indoor formaldehyde pollution. Background Art

[0002] Activated carbon is widely used for indoor formaldehyde adsorption due to its high specific surface area and rich pore structure. Chang et al. (Chem. Phys. Lett. 2020, 757, 137864) used an impregnation hydrothermal method to coat silver and silver oxide on the surface of activated carbon. By modifying the activated carbon to increase the specific surface area and surface oxygen functional groups, the ability of activated carbon to remove formaldehyde was enhanced. Jiao et al. (Appl. Surf. Sci. 2024, 670, 160686) modified activated carbon by nitrogen doping to improve the non-bonded interaction between formaldehyde molecules and activated carbon, thereby enhancing the adsorption of formaldehyde molecules. Fang et al. (Chem. Eng. J. 2018, 334,2050-2057) prepared MnOx / activated carbon by in situ redox reaction, which showed excellent catalytic activity and stability for formaldehyde oxidation at room temperature. Zhu et al. (Adsorpt. Sci. Technol. 2021, 8790974) summarized in detail the factors affecting the removal of formaldehyde by activated carbon and TiO2 / activated carbon. By loading TiO2 on activated carbon, its formaldehyde removal rate can be effectively improved. Chinese patent CN119500085A discloses a method for preparing modified activated carbon for removing formaldehyde, and efficient formaldehyde removal is achieved by impregnating modified activated carbon. Chinese patent CN117414800A discloses a process for long-term purification of formaldehyde using TiO2-modified activated carbon fibers. By reacting a cross-linking agent, a composite solution and the activated carbon fibers, a thin shell of nano-TiO2 photocatalyst can be formed on the activated carbon fibers, thereby realizing in-situ regeneration of the activated carbon fibers. However, traditional activated carbon has the following inherent defects: ① Physical adsorption limitations: Relying solely on physical adsorption, the formaldehyde adsorption capacity is limited (usually ≤10 mg / g), and desorption is prone to occur when the temperature rises or the humidity increases, causing secondary pollution; ② No degradation ability: It cannot decompose formaldehyde molecules, and after adsorption saturation, it needs to be frequently replaced or regenerated at high temperature, which has high cost and low efficiency; ③ Modification technology bottleneck: Existing loaded modified activated carbon (such as loaded TiO2) often has insufficient exposure of active sites due to nanoparticle agglomeration, and traditional impregnation methods make it difficult to achieve uniform dispersion and firm bonding of active components in activated carbon, resulting in low photocatalytic efficiency.

[0003] In recent years, porous TiO2 derived from metal organic frameworks (MOFs) has shown potential in the field of photocatalytic degradation of formaldehyde due to its high specific surface area and tunable active sites. Wei et al. (Colloid. Surface. A. 2025, 717,136824) achieved photodegradation of formaldehyde under visible light by modifying waterborne polyurethane coatings with TiO2 loaded MIL-125. Chinese patent CN115282995A discloses a CuO x / TiO2@CN photocatalyst and its preparation method and application, CuO x / TiO2@CN photocatalysts increase formaldehyde adsorption by pyrolyzing MOF. Chinese patent CN119775580A discloses a defective titanium-based metal-organic framework material, its preparation method and application, a method for photocatalytic degradation of formaldehyde, and a coating composite. By creating structural defects in TiO2@NMX, it is used for efficient and stable photocatalytic oxidation of formaldehyde. However, the composite of MOF-derived TiO2 with activated carbon still faces key challenges: ① Poor structural compatibility: The interface between MOF derivatives and activated carbon is weak, and the composite material is prone to delamination; ② Insufficient process adaptability: Conventional composite methods (such as coating and blending) cannot simultaneously achieve high dispersion of activated carbon, uniform loading of MOF derivatives, and continuity of the activated carbon structure, significantly restricting the improvement of material performance. Summary of the Invention

[0004] In order to overcome the above-mentioned defects, the present invention provides an activated carbon fiber with high efficiency in removing formaldehyde and a preparation method thereof. The core purposes are: 1. By constructing a MOF-derived porous TiO2 / activated carbon composite fiber structure, the physical adsorption and photocatalytic degradation functions are coordinated to break through the limitation of single adsorption capacity; 2. Solve the interfacial bonding problem between MOF derivatives and activated carbon, and realize high dispersion loading and stable and firm composite of active components; 3. Develop a process path that can be prepared on a large scale, and realize the continuous production of composite fibers through electrospinning technology.

[0005] To achieve the above objectives, the technical solution of the present invention is implemented through the following technical solutions: An activated carbon fiber for efficient formaldehyde removal, characterized in that the activated carbon fiber is a composite fiber structure of activated carbon and porous TiO2 derived from a metal organic framework (MOF), and the preparation method of the composite material comprises the following steps: 1) Pretreatment of activated carbon Polyvinyl pyrrolidone (PVP) was added to ethanol and the PVP was completely dissolved by ultrasound to form solution A. A molten salt with a specific surface area of ​​1000-1500 m 2 / g of activated carbon, the weight ratio of activated carbon to PVP was 100:1, to form a mixture B; then the mixture B was planetary ball milled at a ball-to-material ratio of 10:1 and a rotation speed of 300 rpm for 10 h to obtain pretreated activated carbon; 2) Preparation of Ti-MOF precursor A mixed solution C was prepared with a volume ratio of N,N-dimethylformamide and methanol of 2:1. 5 mmol of 2-aminoterephthalic acid was dissolved in the mixed solution C and stirred for 1 hour to form a solution D. 2.5 mmol of titanium (IV) isopropoxide was added to the solution D and stirred for 1 hour to form a solution E. Solution E was poured into a polytetrafluoroethylene-lined reactor and placed at 150°C for 16 hours. After natural cooling, the solution was washed twice with alcohol and dried in vacuum at 100°C for 12 hours to obtain a Ti-MOF precursor. 3) Preparation of TiO2 / activated carbon fiber The activated carbon obtained in step 1) and the Ti-MOF precursor obtained in step 2) were added to ethanol and ultrasonically dispersed for 30 minutes. Then, 1 g of PVP was added and magnetically stirred for 10 hours to obtain a viscous solution F. The viscous solution F was aspirated into a syringe with a 0.7 mm needle and electrospun at a feed rate of 0.01 to 0.05 ml / min and an applied voltage of 15 to 20 kV. The fibers were continuously collected on aluminum foil. The collected fibers were dried in a vacuum oven at 60°C for 10 hours. The fibers were then placed in a 100 ml crucible with a lid, covered with a crucible lid, and placed in a muffle furnace. The temperature was increased to 300 to 500°C at a heating rate of 2°C / min and maintained at this temperature for 3 to 6 hours. TiO2 / activated carbon fibers were obtained after natural cooling.

[0006] The present invention provides an activated carbon fiber with high efficiency in removing formaldehyde and a preparation method thereof, which has the following advantages over the prior art: The present invention provides a novel MOF-derived porous TiO2 / activated carbon composite fiber structure with high-efficiency formaldehyde removal activated carbon fiber, which synergizes physical adsorption and photocatalytic formaldehyde degradation functions and has a significant formaldehyde removal effect; the present invention utilizes an electrostatic spinning method to prepare activated carbon fibers, and its MOF-derived porous TiO2 can be uniformly dispersed in the activated carbon fibers, exposing more active sites, solving the problem of insufficient exposure of active sites due to agglomeration of nanoparticles; at the same time, the MOF-derived porous TiO2 can be firmly combined with the activated carbon fibers, solving the problem that the composite of nanoparticles and activated carbon is prone to desorption, resulting in failure in formaldehyde removal; compared with other formaldehyde-removing activated carbon composite materials, the preparation method of the present invention is simple, low-cost, and the entire preparation process has good process stability, and is suitable for large-scale continuous production of activated carbon composite fibers; the loaded effective substance components are stably loaded on the activated carbon fibers, and can continuously adsorb and degrade formaldehyde for a long time, avoiding secondary pollution. DETAILED DESCRIPTION

[0007] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention are clearly and completely described below in combination with the embodiments of the present invention and comparative examples. Obviously, the described embodiments are 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 making creative efforts are within the scope of protection of the present invention.

[0008] Example 1 1) Pretreatment of activated carbon 0.01 g PVP was added to 20 ml ethanol and ultrasonicated to completely dissolve PVP to form solution A. 1 g of ethanol with a specific surface area of ​​1500 m 2 / g of activated carbon to form a mixed solution B; then the mixed solution B was planetarily ball milled for 10 h at a ball-to-material ratio of 10:1 and a rotation speed of 300 rpm to obtain pretreated activated carbon; 2) Preparation of Ti-MOF precursor A mixed solution C was prepared with a volume ratio of N,N-dimethylformamide and methanol of 2:1. 5 mmol of 2-aminoterephthalic acid was dissolved in the mixed solution C and stirred for 1 hour to form a solution D. 2.5 mmol of titanium (IV) isopropoxide was added to the solution D and stirred for 1 hour to form a solution E. Solution E was poured into a polytetrafluoroethylene-lined reactor and placed at 150°C for 16 hours. After natural cooling, the solution was washed twice with alcohol and dried in vacuum at 100°C for 12 hours to obtain a Ti-MOF precursor. 3) Preparation of TiO2 / activated carbon fiber The activated carbon obtained in step 1) and the Ti-MOF precursor obtained in step 2) were added to ethanol and ultrasonically dispersed for 30 min, and then 1 g of PVP was added and magnetically stirred for 10 h to obtain a viscous solution F; the viscous solution F was aspirated into a syringe with a 0.7 mm needle and electrospun at a feed rate of 0.01 ml / min and an applied voltage of 15 kV, and the fibers were continuously collected on aluminum foil; the collected fibers were dried in a vacuum oven at 60°C for 10 h, and then placed in a 100 ml crucible with a lid, covered with the crucible lid, and placed in a muffle furnace, heated to 400°C at a heating rate of 2°C / min and kept warm for 3 h, and then naturally cooled to obtain TiO2 / activated carbon fibers.

[0009] Example 2 1) Pretreatment of activated carbon 0.01 g PVP was added to 20 ml ethanol and ultrasonicated to completely dissolve PVP to form solution A. 1 g of ethanol with a specific surface area of ​​1500 m 2 / g of activated carbon to form a mixed solution B; then the mixed solution B was planetarily ball milled for 10 h at a ball-to-material ratio of 10:1 and a rotation speed of 300 rpm to obtain pretreated activated carbon; 2) Preparation of Ti-MOF precursor A mixed solution C was prepared with a volume ratio of N,N-dimethylformamide and methanol of 2:1. 5 mmol of 2-aminoterephthalic acid was dissolved in the mixed solution C and stirred for 1 hour to form a solution D. 2.5 mmol of titanium (IV) isopropoxide was added to the solution D and stirred for 1 hour to form a solution E. Solution E was poured into a polytetrafluoroethylene-lined reactor and placed at 150°C for 16 hours. After natural cooling, the solution was washed twice with alcohol and dried in vacuum at 100°C for 12 hours to obtain a Ti-MOF precursor. 3) Preparation of TiO2 / activated carbon fiber The activated carbon obtained in step 1) and the Ti-MOF precursor obtained in step 2) were added to ethanol and ultrasonically dispersed for 30 min, and then 1 g of PVP was added and magnetically stirred for 10 h to obtain a viscous solution F; the viscous solution F was aspirated into a syringe with a 0.7 mm needle and electrospun at a feed rate of 0.05 ml / min and an applied voltage of 20 kV, and the fibers were continuously collected on aluminum foil; the collected fibers were dried in a vacuum oven at 60°C for 10 h, and then placed in a 100 ml crucible with a lid, covered with the crucible lid, and placed in a muffle furnace, heated to 500°C at a heating rate of 2°C / min and kept warm for 3 h, and then naturally cooled to obtain TiO2 / activated carbon fibers.

[0010] Example 3 1) Pretreatment of activated carbon 0.01 g PVP was added to 20 ml ethanol and ultrasonicated to completely dissolve PVP to form solution A. 1 g of ethanol with a specific surface area of ​​1500 m 2 / g of activated carbon to form a mixed solution B; then the mixed solution B was planetarily ball milled for 10 h at a ball-to-material ratio of 10:1 and a rotation speed of 300 rpm to obtain pretreated activated carbon; 2) Preparation of Ti-MOF precursor A mixed solution C was prepared with a volume ratio of N,N-dimethylformamide and methanol of 2:1. 5 mmol of 2-aminoterephthalic acid was dissolved in the mixed solution C and stirred for 1 hour to form a solution D. 2.5 mmol of titanium (IV) isopropoxide was added to the solution D and stirred for 1 hour to form a solution E. Solution E was poured into a polytetrafluoroethylene-lined reactor and placed at 150°C for 16 hours. After natural cooling, the solution was washed twice with alcohol and dried in vacuum at 100°C for 12 hours to obtain a Ti-MOF precursor. 3) Preparation of TiO2 / activated carbon fiber The activated carbon obtained in step 1) and the Ti-MOF precursor obtained in step 2) were added to ethanol and ultrasonically dispersed for 30 min, and then 1 g of PVP was added and magnetically stirred for 10 h to obtain a viscous solution F; the viscous solution F was aspirated into a syringe with a 0.7 mm needle and electrospun at a feed rate of 0.02 ml / min and an applied voltage of 18 kV, and the fibers were continuously collected on aluminum foil; the collected fibers were dried in a vacuum oven at 60°C for 10 h, and then placed in a 100 ml crucible with a lid, covered with the crucible lid, and placed in a muffle furnace, heated to 300°C at a heating rate of 2°C / min and kept warm for 6 h, and then naturally cooled to obtain TiO2 / activated carbon fibers.

[0011] Example 4 1) Pretreatment of activated carbon 0.01 g PVP was added to 20 ml ethanol and ultrasonicated to completely dissolve PVP to form solution A. 1 g of a soluble solid with a specific surface area of ​​1000 m 2 / g of activated carbon to form a mixed solution B; then the mixed solution B was planetarily ball milled for 10 h at a ball-to-material ratio of 10:1 and a rotation speed of 300 rpm to obtain pretreated activated carbon; 2) Preparation of Ti-MOF precursor A mixed solution C was prepared with a volume ratio of N,N-dimethylformamide and methanol of 2:1. 5 mmol of 2-aminoterephthalic acid was dissolved in the mixed solution C and stirred for 1 hour to form a solution D. 2.5 mmol of titanium (IV) isopropoxide was added to the solution D and stirred for 1 hour to form a solution E. Solution E was poured into a polytetrafluoroethylene-lined reactor and placed at 150°C for 16 hours. After natural cooling, the solution was washed twice with alcohol and dried in vacuum at 100°C for 12 hours to obtain a Ti-MOF precursor. 3) Preparation of TiO2 / activated carbon fiber The activated carbon obtained in step 1) and the Ti-MOF precursor obtained in step 2) were added to ethanol and ultrasonically dispersed for 30 min, and then 1 g of PVP was added and magnetically stirred for 10 h to obtain a viscous solution F; the viscous solution F was aspirated into a syringe with a 0.7 mm needle and electrospun at a feed rate of 0.01 ml / min and an applied voltage of 20 kV, and the fibers were continuously collected on aluminum foil; the collected fibers were dried in a vacuum oven at 60°C for 10 h, and then the fibers were placed in a 100 ml crucible with a lid, covered with the crucible lid, and placed in a muffle furnace, heated to 400°C at a heating rate of 2°C / min and kept warm for 4 h, and then naturally cooled to obtain TiO2 / activated carbon fibers.

[0012] Comparative Example 1 1) Preparation of Ti-MOF precursor A mixed solution C was prepared with a volume ratio of N,N-dimethylformamide and methanol of 2:1. 5 mmol of 2-aminoterephthalic acid was dissolved in the mixed solution C and stirred for 1 hour to form a solution D. 2.5 mmol of titanium (IV) isopropoxide was added to the solution D and stirred for 1 hour to form a solution E. Solution E was poured into a polytetrafluoroethylene-lined reactor and placed at 150°C for 16 hours. After natural cooling, the solution was washed twice with alcohol and dried in vacuum at 100°C for 12 hours to obtain a Ti-MOF precursor. 2) Preparation of TiO2 / activated carbon fiber The specific surface area of ​​1 g is 1500 m 2 / g activated carbon and the Ti-MOF precursor obtained in step 1) were added to ethanol and ultrasonically dispersed for 30 min, then 1 g of PVP was added and magnetically stirred for 10 h to obtain a viscous solution F; the viscous solution F was sucked into a syringe with a 0.7 mm needle and electrospun at a feed rate of 0.01 ml / min and an applied voltage of 15 kV, and the fibers were continuously collected on aluminum foil; the collected fibers were dried in a vacuum oven at 60°C for 10 h, and then the fibers were placed in a 100 ml crucible with a lid, covered with the crucible lid, and placed in a muffle furnace, heated to 400°C at a heating rate of 2°C / min and kept warm for 3 h, and then naturally cooled to obtain TiO2 / activated carbon fibers.

[0013] Comparative Example 2 1) Pretreatment of activated carbon 0.01 g PVP was added to 20 ml ethanol and ultrasonicated to completely dissolve PVP to form solution A. 1 g of ethanol with a specific surface area of ​​1500 m 2 / g of activated carbon to form a mixed solution B; then the mixed solution B was planetarily ball milled for 10 h at a ball-to-material ratio of 10:1 and a rotation speed of 300 rpm to obtain pretreated activated carbon; 2) Preparation of Ti precursor A mixed solution C with a volume ratio of N,N-dimethylformamide and methanol of 2:1 was prepared; 2.5 mmol of titanium (IV) isopropoxide was added to solution C and stirred for 1 h to form solution E; solution E was poured into a polytetrafluoroethylene-lined reactor and placed at 150°C for 16 h; after natural cooling, the mixture was washed twice with alcohol and vacuum dried at 100°C for 12 h to obtain a Ti precursor; 3) Preparation of TiO2 / activated carbon fiber The activated carbon obtained in step 1) and the Ti precursor obtained in step 2) were added to ethanol and ultrasonically dispersed for 30 min. 1 g of PVP was then added and magnetically stirred for 10 h to obtain a viscous solution F. The viscous solution F was aspirated into a syringe with a 0.7 mm needle and electrospun at a feed rate of 0.01 ml / min and an applied voltage of 15 kV. The fibers were continuously collected on aluminum foil. The collected fibers were dried in a vacuum oven at 60°C for 10 h. The fibers were then placed in a 100 ml crucible with a lid, covered with the crucible lid, and placed in a muffle furnace, heated to 400°C at a heating rate of 2°C / min and kept at that temperature for 3 h. TiO2 / activated carbon fibers were obtained after natural cooling.

[0014] Comparative Example 3 1) Pretreatment of activated carbon 0.01 g PVP was added to 20 ml ethanol and ultrasonicated to completely dissolve PVP to form solution A. 1 g of ethanol with a specific surface area of ​​1500 m 2 / g of activated carbon to form a mixed solution B; then the mixed solution B was planetarily ball milled for 10 h at a ball-to-material ratio of 10:1 and a rotation speed of 300 rpm to obtain pretreated activated carbon; 2) Preparation of Ti-MOF precursor A mixed solution C was prepared with a volume ratio of N,N-dimethylformamide and methanol of 2:1. 5 mmol of 2-aminoterephthalic acid was dissolved in the mixed solution C and stirred for 1 hour to form a solution D. 2.5 mmol of titanium (IV) isopropoxide was added to the solution D and stirred for 1 hour to form a solution E. Solution E was poured into a polytetrafluoroethylene-lined reactor and placed at 150°C for 16 hours. After natural cooling, the solution was washed twice with alcohol and dried in vacuum at 100°C for 12 hours to obtain a Ti-MOF precursor. 3) Preparation of TiO2 / activated carbon The activated carbon obtained in step 1) and the Ti-MOF precursor obtained in step 2) were added to ethanol and ultrasonically dispersed for 30 min. Then, 1 g of PVP was added and magnetically stirred for 10 h to obtain a viscous solution F. The viscous solution F was then dried and placed in a 100 ml crucible with a lid. The crucible was covered and placed in a muffle furnace, heated to 400°C at a heating rate of 2°C / min and kept warm for 3 h. After natural cooling, TiO2 / activated carbon was obtained.

[0015] Comparative Example 4 1) Pretreatment of activated carbon 0.01 g PVP was added to 20 ml ethanol and ultrasonicated to completely dissolve PVP to form solution A. 1 g of ethanol with a specific surface area of ​​1500 m 2 / g of activated carbon to form a mixed solution B; then the mixed solution B was planetarily ball milled for 10 h at a ball-to-material ratio of 10:1 and a rotation speed of 300 rpm to obtain pretreated activated carbon; 2) Preparation of Ti-MOF precursor A mixed solution C was prepared with a volume ratio of N,N-dimethylformamide and methanol of 2:1. 5 mmol of 2-aminoterephthalic acid was dissolved in the mixed solution C and stirred for 1 hour to form a solution D. 2.5 mmol of titanium (IV) isopropoxide was added to the solution D and stirred for 1 hour to form a solution E. Solution E was poured into a polytetrafluoroethylene-lined reactor and placed at 150°C for 16 hours. After natural cooling, the solution was washed twice with alcohol and dried in vacuum at 100°C for 12 hours to obtain a Ti-MOF precursor. 3) Preparation of TiO2 / activated carbon fiber The activated carbon obtained in step 1) and the Ti-MOF precursor obtained in step 2) were added to ethanol and ultrasonically dispersed for 30 min, and then 1 g of PVP was added and magnetically stirred for 10 h to obtain a viscous solution F; the viscous solution F was aspirated into a syringe with a 0.7 mm needle and electrospun at a feed rate of 0.01 ml / min and an applied voltage of 15 kV, and the fibers were continuously collected on aluminum foil; the collected fibers were dried in a vacuum oven at 60°C for 10 h, and then the fibers were placed in a 100 ml uncovered crucible, placed in a muffle furnace, heated to 400°C at a heating rate of 2°C / min, and kept warm for 3 h, and then naturally cooled to obtain TiO2 / activated carbon fibers.

[0016] Comparative Example 5 1) Pretreatment of activated carbon 0.01 g PVP was added to 20 ml ethanol and ultrasonicated to completely dissolve PVP to form solution A. 1 g of ethanol with a specific surface area of ​​1500 m 2 / g of activated carbon to form a mixed solution B; then the mixed solution B was planetarily ball milled for 10 h at a ball-to-material ratio of 10:1 and a rotation speed of 300 rpm to obtain pretreated activated carbon; 2) Preparation of Ti-MOF precursor A mixed solution C was prepared with a volume ratio of N,N-dimethylformamide and methanol of 2:1. 5 mmol of 2-aminoterephthalic acid was dissolved in the mixed solution C and stirred for 1 hour to form a solution D. 2.5 mmol of titanium (IV) isopropoxide was added to the solution D and stirred for 1 hour to form a solution E. Solution E was poured into a polytetrafluoroethylene-lined reactor and placed at 150°C for 16 hours. After natural cooling, the solution was washed twice with alcohol and dried in vacuum at 100°C for 12 hours to obtain a Ti-MOF precursor. 3) Preparation of Ti-MOF / activated carbon fiber The activated carbon obtained in step 1) and the Ti-MOF precursor obtained in step 2) were added to ethanol and ultrasonically dispersed for 30 min. Then, 1 g of PVP was added and magnetically stirred for 10 h to obtain a viscous solution F. The viscous solution F was aspirated into a syringe with a 0.7 mm needle and electrospun at a feed rate of 0.01 ml / min and an applied voltage of 15 kV. The fibers were continuously collected on aluminum foil. The collected fibers were dried in a vacuum oven at 60°C for 10 h and naturally cooled to obtain Ti-MOF / activated carbon fibers.

[0017] The differences between the comparative example and Example 1 are as follows: Comparative Example 1 does not have an activated carbon pretreatment step; Comparative Example 2 is a Ti precursor without a MOF structure; Comparative Example 3 does not have an electrospinning step; Comparative Example 4 is calcined in an uncovered crucible; Comparative Example 5 does not have a calcination step to obtain Ti-MOF / activated carbon fiber.

[0018] The samples obtained in the above examples and comparative examples were tested for formaldehyde removal rate according to "JC / T 2188-2013 Purification Performance of Indoor Air Purification Adsorption Materials". The results are shown in the following table: time Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 1h removal rate% 97.8 96.2 96.8 95.4 88.2 90.4 72.4 69.1 82.5 6h removal rate% 99.4 98.9 99.1 98.7 92.4 92.6 78.9 73.3 88.6 12h removal rate% 99.6 99.1 99.2 99.0 86.1 87.3 70.8 70.8 90.2 24h removal rate% 99.6 99.0 99.2 99.1 78.4 82.5 61.2 60.8 86.4

Claims

1. An activated carbon fiber with high efficiency in removing formaldehyde, characterized in that: The activated carbon fiber is a composite fiber structure of activated carbon and porous TiO2 derived from a metal organic framework (MOF). The preparation method of the composite material includes the following steps: 1) Pretreatment of activated carbon Polyvinyl pyrrolidone (PVP) was added to ethanol and the PVP was completely dissolved by ultrasound to form solution A. A molten salt with a specific surface area of ​​1000-1500 m 2 / g of activated carbon, the weight ratio of activated carbon to PVP was 100:1, to form a mixture B; then the mixture B was planetary ball milled at a ball-to-material ratio of 10:1 and a rotation speed of 300 rpm for 10 h to obtain pretreated activated carbon; 2) Preparation of Ti-MOF precursor A mixed solution C was prepared with a volume ratio of N,N-dimethylformamide and methanol of 2:

1. 5 mmol of 2-aminoterephthalic acid was dissolved in the mixed solution C and stirred for 1 hour to form a solution D. 2.5 mmol of titanium (IV) isopropoxide was added to the solution D and stirred for 1 hour to form a solution E. Solution E was poured into a polytetrafluoroethylene-lined reactor and placed at 150°C for 16 hours. After natural cooling, the solution was washed twice with alcohol and dried in vacuum at 100°C for 12 hours to obtain a Ti-MOF precursor. 3) Preparation of TiO2 / activated carbon fiber The activated carbon obtained in step 1) and the Ti-MOF precursor obtained in step 2) were added to ethanol and ultrasonically dispersed for 30 min. 1 g of PVP was then added and magnetically stirred for 10 h to obtain a viscous solution F. The viscous solution F was aspirated into a syringe with a 0.7 mm needle and electrospun at a feed rate of 0.01 to 0.05 ml / min and an applied voltage of 15 to 20 kV. The fibers were continuously collected on aluminum foil. The collected fibers were dried in a vacuum oven at 60°C for 10 h. The fibers were then placed in a 100 ml crucible with a lid, covered with the crucible lid, and placed in a muffle furnace, heated to 300 to 500°C at a heating rate of 2°C / min and kept at that temperature for 3 to 6 h. TiO2 / activated carbon fibers were obtained after natural cooling.