A gas sensor based on metal organic framework and cellulose and a preparation method thereof

Abstract

This invention belongs to the field of gas analysis and detection, and relates to a gas sensor based on metal-organic frameworks and cellulose, as well as its preparation method. First, HKUST-1 is synthesized via a solvothermal method. Then, silanized modified nanocellulose is blended with HKUST-1, followed by vacuum filtration to form a membrane. After drying, a composite membrane is obtained, which is then used to fabricate the gas sensor. The composite membrane prepared by this invention exhibits excellent performance in energy harvesting, gas sensing, and ethylene adsorption. Furthermore, the preparation method of this invention is simple, easy to operate, and low in cost.

Description

Technical Field

[0001] This invention belongs to the field of gas analysis and detection technology, and relates to a gas sensor based on metal-organic framework and cellulose and its preparation method. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] With technological advancements, cellulose nanomaterials such as cellulose nanocrystals (CNC), cellulose nanofibers (CNF), and lignin-containing cellulose nanofibers (LCNF) have been developed. Due to their abundant hydroxyl groups and high specific surface area, cellulose nanocomposites exhibit unique advantages in fields such as medical dressings, food packaging, and flexible electronics.

[0004] Triboelectric nanogenerators (TENGs) are devices that harvest frictional energy from the environment and convert it into electrical energy based on electrostatic induction and triboelectric coupling. They currently have numerous applications in gas sensors. Integrating metal-organic frameworks (MOFs) as gas-sensitive materials into TENGs can create TENG-based gas sensors. Some studies have grown metal-organic frameworks by placing carboxyl-containing flexible carbon nanofiber membranes in a precursor solution of metal-organic frameworks, obtaining metal-organic framework / carbon nanofiber composite membrane materials for gas adsorption and separation. However, in-situ synthesis methods are prone to pore blockage, affecting subsequent gas detection performance.

[0005] On the other hand, fruits and vegetables continuously release endogenous ethylene during their growth, promoting fruit ripening. However, fruits and vegetables continue to release ethylene after harvesting, which is detrimental to their transportation and storage. Common methods for ethylene detection include gas chromatography, optical sensors, and colorimetric sensors, but none of these can achieve low-cost, convenient, and rapid detection.

[0006] Therefore, some studies have found that HKUST-1 has ethylene absorption capacity. However, HKUST-1 is difficult to form a film. Its film-forming properties are often improved by introducing high molecular polymers. However, no MOF membrane that can directly detect the ethylene concentration by voltage has been developed yet.

[0007] Therefore, there is an urgent need to develop a gas sensor that combines real-time monitoring and ethylene adsorption functions. Summary of the Invention

[0008] To address the aforementioned problems, this invention provides a gas sensor based on a metal-organic framework and cellulose, along with its preparation method. This invention reveals that a composite membrane prepared by blending a copper-based metal-organic framework material with silanized modified nanocellulose can determine the concentration of ethylene by measuring the open-circuit voltage under an ethylene atmosphere, achieving real-time and highly sensitive detection of ethylene concentration.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] In a first aspect, the present invention provides a method for fabricating a gas sensor based on a metal-organic framework and cellulose, comprising:

[0011] A copper-based metal-organic framework material and a silanized modified cellulose nanoparticle solution were mixed uniformly at a preset temperature to obtain a mixed solution.

[0012] The mixed solution was filtered into a membrane and dried to obtain a composite membrane;

[0013] The composite membrane is used as an electrode to assemble a gas sensor;

[0014] The mass ratio of the silanized modified nanocellulose to the copper-based metal-organic framework material is 5-30:1;

[0015] The copper-based metal-organic framework material is HKUST-1.

[0016] In a second aspect, the present invention provides a gas sensor based on a metal-organic framework and cellulose prepared by the above-described method.

[0017] Beneficial effects of the present invention

[0018] (1) The present invention uses copper-based metal-organic framework material and silanized modified nanocellulose to prepare a composite membrane. The concentration of ethylene can be determined by measuring the open circuit voltage under ethylene atmosphere, thus realizing real-time and high-sensitivity detection of ethylene concentration.

[0019] (2) The present invention modifies lignin-containing cellulose nanofibers with silane, which effectively improves the hydrophilicity of the composite membrane and enhances its durability under extreme conditions.

[0020] (3) The composite membrane prepared by the present invention can be used for the detection and adsorption of ethylene gas.

[0021] (4) The preparation method of the present invention is simple and the raw materials are widely available, which can effectively reduce the preparation cost of gas sensors.

[0022] (5) The present invention adopts a stepwise synthesis strategy to synthesize MOFs by solvothermal means, which can achieve precise control of their morphology and size, and avoid problems such as pore blockage caused by in-situ synthesis, which is beneficial to the subsequent gas detection process. Attached Figure Description

[0023] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. Exemplary embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0024] Figure 1 The image shows a scanning electron microscope (SEM) image of HKUST-1 prepared in Example 3.

[0025] Figure 2 The image shows the infrared spectra of HKUST-1 prepared in Example 3 and the cellulose composite membranes synthesized in Examples 1-4. The inset shows the characteristic peaks related to the silanization modification of LCNF.

[0026] Figure 3 The nitrogen adsorption / desorption curves are for the cellulose composite membrane synthesized in Example 3.

[0027] Figure 4 This is the voltage response of Example 3 at different ethylene concentrations. Detailed Implementation

[0028] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of skill in the art. The reagents and raw materials used in this invention are readily available through conventional means, and unless otherwise specified, they are used in accordance with conventional methods in the art or product instructions. Similarly, unless otherwise specified, the test methods of this invention are performed in accordance with conventional methods in the art or industry-standard methods or practices. Furthermore, any methods and materials similar to or equivalent to those described herein may be applied to the methods of this invention. The preferred embodiments and materials described herein are for illustrative purposes only.

[0030] This invention provides a method for fabricating a gas sensor based on a metal-organic framework and cellulose, comprising:

[0031] A copper-based metal-organic framework material and a silanized modified cellulose nanoparticle solution were mixed uniformly at a preset temperature to obtain a mixed solution.

[0032] The mixed solution was filtered into a membrane and dried to obtain a composite membrane;

[0033] The composite membrane is used as an electrode to assemble a gas sensor.

[0034] The aforementioned "nanocellulose" is selected from, but not limited to, one or a mixture of several of cellulose nanocrystals, cellulose nanofibers, and lignin-containing cellulose nanofibers. The aim is to select raw materials whose main component is "nanocellulose". Those skilled in the art can routinely select and replace the above-mentioned nanocellulose types according to factors such as yield and economy. Preferably, lignin-containing cellulose nanofibers are used as raw materials to obtain better performance.

[0035] The type of copper-based metal-organic framework material can affect the performance of gas sensors. Therefore, this invention studies the types of copper-based metal-organic framework materials. Preferably, the copper-based metal-organic framework material is HKUST-1 to better improve the sensitivity of gas detection.

[0036] Preferably, the preparation method of HKUST-1 includes: dissolving copper salt in N,N-dimethylformamide, adding ethanol and water, and finally adding 1,3,5-benzenetricarboxylic acid. After complete dissolution, the solution is ultrasonically dispersed, and then reacted at 85 ℃-95 ℃ for 20 h-24 h. The precipitate is collected, washed, and dried to obtain the final product. This invention synthesizes MOFs using a solvothermal method, which allows for precise control of their morphology and size, while avoiding problems such as pore blockage caused by in-situ synthesis, thus facilitating subsequent gas detection processes.

[0037] The ratio of silanized modified nanocellulose to copper-based metal-organic framework materials affects the performance of gas sensors. Therefore, this invention studies the ratio of silanized modified nanocellulose to copper-based metal-organic framework materials. Preferably, the mass ratio of silanized modified nanocellulose to copper-based metal-organic framework materials is 20-30:1, more preferably 20:1, to obtain better detection results.

[0038] The amount of nanocellulose and the reaction conditions of the silane coupling agent affect the silane modification effect. Therefore, this invention studies the amount of nanocellulose and the reaction conditions of the silane coupling agent. Preferably, the preparation method of the silanized modified nanocellulose includes:

[0039] Nanocellulose and silane coupling agent are mixed evenly in a solvent at a mass ratio of 1:1-1.1, and reacted at 80 ℃-90 ℃ for 4 h-6 h to obtain the final product. This invention improves the hydrophilicity of the composite membrane, its durability under extreme conditions, and its detection sensitivity through silane modification.

[0040] To obtain better detection sensitivity, the present invention screened the types of silane coupling agents. Preferably, the silane coupling agent is triethoxy-1H,1H,2H,2H-tridecylfluoron-octylsilane (CAS No.: 51851-37-7) to better improve detection sensitivity.

[0041] To ensure uniform mixing of the copper-based metal-organic framework material and the silanized modified nanocellulose solution, the present invention studied the blending temperature. Preferably, the preset temperature is 50 ℃-60 ℃ to ensure thorough mixing and improve the sensitivity of subsequent gas detection.

[0042] The concentration of the silanized modified cellulose nanoparticle solution affects the blending effect of the silanized modified cellulose nanoparticles and copper-based metal-organic framework materials. Therefore, this invention studies the concentration of the silanized modified cellulose nanoparticle solution. Preferably, the mass concentration of the silanized modified cellulose nanoparticle solution is 0.5%-1% to improve the mixing effect and the sensitivity of gas detection.

[0043] The present invention dries the composite membrane at room temperature to avoid damage to the composite membrane caused by high temperature, which would affect the gas detection effect. Preferably, the drying temperature is 20 ℃-25 ℃ to improve the drying efficiency.

[0044] The present invention will be further described in detail below with reference to specific embodiments. It should be noted that the specific embodiments are explanations of the present invention and not limitations thereof.

[0045] Example 1

[0046] This embodiment provides a gas sensor based on metal-organic frameworks and cellulose, and its preparation method, including the following steps:

[0047] (1) Synthesis of HKUST-1: 2 g of copper nitrate trihydrate was dissolved in 85 mL of N,N-dimethylformamide at 400 rpm, followed by the addition of 85 mL of ethanol and 85 mL of deionized water. Finally, 1 g of 1,3,5-benzenetricarboxylic acid was added, and the solution was sonicated for 30 min after complete dissolution. The solution was then transferred to a high-pressure reactor with a polytetrafluoroethylene substrate and reacted at 85 °C for 24 h. After the reaction, the mixture was washed with N,N-dimethylformamide and dichloromethane, and the precipitate was dried in a vacuum drying oven at 45 °C for 24 h.

[0048] (2) Silanization modification of lignin-containing cellulose nanofibers: An ethanol and aqueous solution with a volume ratio of 8:2 was prepared as a hydrolysate, and then triethoxy-1H,1H,2H,2H-tridecylfluoro-n-octylsilane was added to a mass fraction of 1 wt%, and stirred at room temperature for 2 h. Then, lignin-containing cellulose nanofibers were added to a mass fraction of 1 wt%, and the reaction was carried out at 80 ℃ for 4 h. After the reaction was completed, unreacted triethoxy-1H,1H,2H,2H-tridecylfluoro-n-octylsilane was removed with ethanol. Then, the obtained silanized modified LCNF was prepared into a 0.5 wt% solution with ethanol.

[0049] (3) Preparation of cellulose composite membrane loaded with metal-organic framework: 0.5 wt% silanized modified LCNF and HKUST-1 were mixed at a mass ratio of 5:1; then stirred at 50 ℃ and 400 rpm for 5 h; after the mixing was completed, the membrane was formed by vacuum filtration, and then wrapped with filter paper and dried at room temperature for 24 h.

[0050] (4) Assembly and testing of the gas sensor: The prepared circular composite membrane (radius 15 mm, thickness 0.5 mm) and transparent VHB (double-sided adhesive, radius 15 mm, thickness 1 mm) were assembled on a linear motor with a sealed box. A copper wire was connected between the composite membrane and the VHB as a current collector and connected to an electrometer to output an electrical signal. Then, ethylene gas was introduced into the sealed box, and its output voltage under air and different concentrations of ethylene was measured.

[0051] (5) The linear regression equation for the voltage response under different ethylene concentrations is obtained by fitting the linear relationship between concentration and voltage response value using the least squares method: y = 0.0040x, where x is the ethylene gas concentration and y represents the voltage response value.

[0052] In this embodiment, the voltage response reached 26.45% when the ethylene concentration was 70 ppm. The goodness of fit of the linear regression equation for the voltage response at different ethylene concentrations, R0 2 =0.9980.

[0053] Example 2

[0054] This embodiment provides a gas sensor based on metal-organic frameworks and cellulose, and its preparation method, including the following steps:

[0055] (1) Synthesis of HKUST-1: 2 g of copper nitrate trihydrate was dissolved in 85 mL of N,N-dimethylformamide at 400 rpm, followed by the addition of 85 mL of ethanol and 85 mL of deionized water. Finally, 1 g of 1,3,5-benzenetricarboxylic acid was added, and the solution was sonicated for 30 min after complete dissolution. The solution was then transferred to a high-pressure reactor with a polytetrafluoroethylene substrate and reacted at 85 °C for 24 h. After the reaction, the mixture was washed with N,N-dimethylformamide and dichloromethane, and the precipitate was dried in a vacuum drying oven at 45 °C for 24 h.

[0056] (2) Silanization modification of lignin-containing cellulose nanofibers: An ethanol and aqueous solution with a volume ratio of 8:2 was prepared as a hydrolysate, and then triethoxy-1H,1H,2H,2H-tridecylfluoro-n-octylsilane was added to a mass fraction of 1 wt%, and stirred at room temperature for 2 h. Then, lignin-containing cellulose nanofibers were added to a mass fraction of 1 wt%, and the reaction was carried out at 80 ℃ for 4 h. After the reaction was completed, unreacted triethoxy-1H,1H,2H,2H-tridecylfluoro-n-octylsilane was removed with ethanol. Then, the obtained silanized modified LCNF was prepared into a 0.5 wt% solution with ethanol.

[0057] (3) Preparation of cellulose composite membrane supported on metal-organic framework: 0.5 wt% silanized modified LCNF was mixed with HKUST-1 at a mass ratio of 10:1. Then the mixture was stirred at 50 ℃ and 400 rpm for 5 h. After the mixing was completed, the membrane was formed by vacuum filtration, and then wrapped with filter paper and dried at room temperature for 24 h.

[0058] (4) Assembly and testing of the gas sensor: The prepared circular composite membrane (radius 15 mm, thickness 0.5 mm) and transparent VHB (double-sided adhesive, radius 15 mm, thickness 1 mm) were assembled on a linear motor with a sealed box. A copper wire was connected between the composite membrane and the VHB as a current collector and connected to an electrometer to output an electrical signal. Then, ethylene gas was introduced into the sealed box, and its output voltage under air and different concentrations of ethylene was measured.

[0059] (5) The linear regression equation for the voltage response under different ethylene concentrations is obtained by fitting the linear relationship between concentration and voltage response value using the least squares method: y = 0.0021x, where x is the ethylene gas concentration and y represents the voltage response value.

[0060] In this embodiment, the voltage response reached 15.46% when the ethylene concentration was 70 ppm. The goodness of fit of the linear regression equation for the voltage response at different ethylene concentrations, R0 2 =0.9970.

[0061] Example 3

[0062] This embodiment provides a gas sensor based on metal-organic frameworks and cellulose, and its preparation method, including the following steps:

[0063] (1) Synthesis of HKUST-1: 2 g of copper nitrate trihydrate was dissolved in 85 mL of N,N-dimethylformamide at 400 rpm, followed by the addition of 85 mL of ethanol and 85 mL of deionized water. Finally, 1 g of 1,3,5-benzenetricarboxylic acid was added, and the solution was sonicated for 30 min after complete dissolution. The solution was then transferred to a high-pressure reactor with a polytetrafluoroethylene substrate and reacted at 85 °C for 24 h. After the reaction, the mixture was washed with N,N-dimethylformamide and dichloromethane, and the precipitate was dried in a vacuum drying oven at 45 °C for 24 h.

[0064] (2) Silanization modification of lignin-containing cellulose nanofibers: An ethanol and aqueous solution with a volume ratio of 8:2 was prepared as a hydrolysate, and then triethoxy-1H,1H,2H,2H-tridecylfluoro-n-octylsilane was added to a mass fraction of 1 wt%, and stirred at room temperature for 2 h. Then, lignin-containing cellulose nanofibers were added to a mass fraction of 1 wt%, and the reaction was carried out at 80 ℃ for 4 h. After the reaction was completed, unreacted triethoxy-1H,1H,2H,2H-tridecylfluoro-n-octylsilane was removed with ethanol. Then, the obtained silanized modified LCNF was prepared into a 0.5 wt% solution with ethanol.

[0065] (3) Preparation of cellulose composite membrane supported on metal-organic framework: 0.5 wt% silanized modified LCNF was mixed with HKUST-1 at a mass ratio of 20:1. Then the mixture was stirred at 50 ℃ and 400 rpm for 5 h. After the mixing was completed, the membrane was formed by vacuum filtration, and then wrapped with filter paper and dried at room temperature for 24 h.

[0066] (4) Assembly and testing of the gas sensor: The prepared circular composite membrane (radius 15 mm, thickness 0.5 mm) and transparent VHB (double-sided adhesive, radius 15 mm, thickness 1 mm) were assembled on a linear motor with a sealed box. A copper wire was connected between the composite membrane and the VHB as a current collector and connected to an electrometer to output an electrical signal. Then, ethylene gas was introduced into the sealed box, and its output voltage under air and different concentrations of ethylene was measured.

[0067] (5) The linear regression equation for the voltage response under different ethylene concentrations is obtained by fitting the linear relationship between concentration and voltage response value using the least squares method: y = 0.0029x, where x is the ethylene gas concentration and y represents the voltage response value.

[0068] In this embodiment, the voltage response reached 17.94% when the ethylene concentration was 70 ppm. The goodness of fit of the linear regression equation for the voltage response at different ethylene concentrations, R0 2 =0.9999.

[0069] The same method was used to test ammonia, carbon dioxide, ethanol, sulfur dioxide, etc., and the results are as follows: when the ammonia concentration is 70 ppm, the voltage response is 4.13%; when the carbon dioxide concentration is 70 ppm, the voltage response is 10.41%; when the ethanol concentration is 70 ppm, the voltage response is 5.17%; and when the sulfur dioxide concentration is 70 ppm, the voltage response is 4.15%. It can be seen that the composite membrane of the present invention has a specific response capability to ethylene.

[0070] Example 4

[0071] This embodiment provides a gas sensor based on metal-organic frameworks and cellulose, and its preparation method, including the following steps:

[0072] (1) Synthesis of HKUST-1: 2 g of copper nitrate trihydrate was dissolved in 85 mL of N,N-dimethylformamide at 400 rpm, followed by the addition of 85 mL of ethanol and 85 mL of deionized water. Finally, 1 g of 1,3,5-benzenetricarboxylic acid was added, and the solution was sonicated for 30 min after complete dissolution. The solution was then transferred to a high-pressure reactor with a polytetrafluoroethylene substrate and reacted at 85 °C for 24 h. After the reaction, the mixture was washed with N,N-dimethylformamide and dichloromethane, and the precipitate was dried in a vacuum drying oven at 45 °C for 24 h.

[0073] (2) Silanization modification of lignin-containing cellulose nanofibers: An ethanol and aqueous solution with a volume ratio of 8:2 was prepared as a hydrolysate, and then triethoxy-1H,1H,2H,2H-tridecylfluoro-n-octylsilane was added to a mass fraction of 1 wt%, and stirred at room temperature for 2 h. Then, lignin-containing cellulose nanofibers were added to a mass fraction of 1 wt%, and the reaction was carried out at 80 ℃ for 4 h. After the reaction was completed, unreacted triethoxy-1H,1H,2H,2H-tridecylfluoro-n-octylsilane was removed with ethanol. Then, the obtained silanized modified LCNF was prepared into a 0.5 wt% solution with ethanol.

[0074] (3) Preparation of cellulose composite membrane supported on metal-organic framework: 0.5 wt% silanized modified LCNF was mixed with HKUST-1 at a mass ratio of 30:1. Then the mixture was stirred at 50 ℃ and 400 rpm for 5 h. After the mixing was completed, the membrane was formed by vacuum filtration, and then wrapped with filter paper and dried at room temperature for 24 h.

[0075] (4) Assembly and testing of the gas sensor: The prepared circular composite membrane (radius 15 mm, thickness 0.5 mm) and transparent VHB (double-sided adhesive, radius 15 mm, thickness 1 mm) were assembled on a linear motor with a sealed box. A copper wire was connected between the composite membrane and the VHB as a current collector and connected to an electrometer to output an electrical signal. Then, ethylene gas was introduced into the sealed box, and its output voltage under air and different concentrations of ethylene was measured.

[0076] (5) The linear regression equation for the voltage response under different ethylene concentrations is obtained by fitting the linear relationship between concentration and voltage response value using the least squares method: y = 0.0025x, where x is the ethylene gas concentration and y represents the voltage response value.

[0077] In this embodiment, the voltage response reached 21.53% when the ethylene concentration was 70 ppm. The goodness of fit of the linear regression equation for the voltage response at different ethylene concentrations, R0 2 =0.9506.

[0078] Figure 1 The image shows a scanning electron microscope image of HKUST-1, which has an octahedral structure with a size of 4-20 μm.

[0079] Figure 2 The infrared spectra of HKUST-1 and Examples 1-4 are shown at 1648 cm⁻¹. -1 -1365 cm -1 The corresponding peaks are the asymmetric and symmetric stretching vibrations of the carboxyl group, indicating that the carboxyl group of 1,3,5-benzenetricarboxylic acid is in a bidentate bridging mode with the metal ion center, 733 cm⁻¹. -1 With 488 cm -1 The characteristic peak at 1107 cm⁻¹ corresponds to the Cu-O tensile vibration band. -1 The corresponding peak is the CO-Cu tensile vibration. The inset shows the characteristic peak related to LCNF silanization modification, at 1235 cm⁻¹. 1 and 1140 cm 1 The characteristic peaks appearing at 1100 cm⁻¹ correspond to the stretching vibrations of -CF₂ and -CF₃, respectively. 1 -1000 cm 1 The peaks at these locations are typical of Si-O-Si and Si-OC, and these characteristic peaks confirm that the silane coupling agent successfully modified LCNF.

[0080] Figure 3The nitrogen adsorption / desorption curve for Example 3 is a type I adsorption isotherm. The adsorption amount increases under low relative nitrogen pressure, indicating that the sample has a rich pore structure.

[0081] Figure 4 The open-circuit voltages in Example 3 are the corresponding voltages at different ethylene concentrations. As the ethylene concentration increases, the open-circuit voltages gradually decrease.

[0082] Comparative Example 1

[0083] The difference from Example 3 is that HKUST-1 was not added.

[0084] The voltage of the gas sensor in air decreased by 12.75% compared to Example 3, and the open-circuit voltage did not change significantly after ethylene was introduced.

[0085] Comparative Example 2

[0086] The difference from Example 3 is that methyltrimethoxysilane is used instead of triethoxy-1H,1H,2H,2H-tridecylfluoron-octylsilane.

[0087] The linear regression equation for the voltage response at different ethylene concentrations is obtained by fitting the linear relationship between concentration and voltage response value using the least squares method: y = 0.0027x, where x is the ethylene gas concentration and y represents the voltage response value.

[0088] The voltage response at 70 ppm was 17.21%. The goodness of fit of the linear regression equation for the voltage response at different ethylene concentrations was R0. 2 =0.9819.

[0089] As can be seen from the comparison between Example 3 and Comparative Example 1, the present invention achieves accurate detection of ethylene gas by combining HKUST-1 and silanized modified nanocellulose.

[0090] As can be seen from the comparison between Example 3 and Comparative Example 2, the modification of nanocellulose with triethoxy-1H,1H,2H,2H-tetrafluoron-octylsilane can better improve the sensitivity of ethylene gas detection compared with methyltrimethoxysilane.

[0091] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a metal organic framework and cellulose based gas sensor, characterized by, include: A copper-based metal-organic framework material and a silanized modified cellulose nanoparticle solution were mixed uniformly at a preset temperature to obtain a mixed solution. The mixed solution was filtered into a membrane and dried to obtain a composite membrane; The composite membrane is used as an electrode to assemble a gas sensor, thus obtaining the desired result. The mass ratio of the silanized modified nanocellulose to the copper-based metal-organic framework material is 20-30:1; The copper-based metal-organic framework material is HKUST-1; The preparation method of HKUST-1 includes: dissolving copper salt in N,N-dimethylformamide, then adding ethanol and water, and finally adding 1,3,5-benzenetricarboxylic acid. After complete dissolution, the mixture is ultrasonically dispersed and then reacted at 85 ℃-95 ℃ for 20 h-24 h. The precipitate is collected, washed, and dried to obtain the final product. The preparation method of the silanized modified nanocellulose includes: mixing nanocellulose and silane coupling agent in a solvent at a mass ratio of 1:1-1.1, and reacting at 80 ℃-90 ℃ for 4 h-6 h to obtain the nanocellulose. The silane coupling agent is triethoxy-1H,1H,2H,2H-tetrafluoron-octylsilane; The composite membrane is used for the detection and adsorption of ethylene gas.

2. The method for fabricating a gas sensor based on a metal-organic framework and cellulose as described in claim 1, characterized in that, The preset temperature is 50 ℃-60 ℃.

3. The method for fabricating a gas sensor based on a metal-organic framework and cellulose as described in claim 1, characterized in that, The mass concentration of the silanized modified nanocellulose solution is 0.5%-1%.

4. The method for fabricating a gas sensor based on a metal-organic framework and cellulose as described in claim 1, characterized in that, The drying temperature is 20 ℃-25 ℃.

5. A gas sensor based on metal-organic framework and cellulose prepared by the method of any one of claims 1-4.

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