Method for constructing electrochemical sensor of biomass three-dimensional graphene
By regulating the crosslinking structure and carbonization collapse process of tofu-based or egg-based materials, heteroatom-doped 3D carbon materials with continuous charge transfer channels are prepared, which solves the problem that the complexity of pores in biomass three-dimensional carbon materials affects the sensing signal, and achieves more efficient electrochemical signal amplification and sensor performance improvement.
Patent Information
- Application Number
- CN202411585049.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-07
- Publication Date
- 2025-03-11
AI Technical Summary
Although the rich pores and large specific surface area of biomass three-dimensional carbon materials are conducive to the amplification of electrochemical signals, the large number of fine and deep pores and complex pore size distributions that are difficult to control will affect the mass transfer during the sensing process, and in turn affect the electrochemical response signal, resulting in the electrochemical response information being easily masked by the charge and discharge process, which is thus not conducive to the construction of sensors.
By utilizing the oxygen-containing functional groups in tofu-based or egg-based materials, the crosslinking structure of the precursor is regulated, and a multi-step carbonization and collapse process is carried out to obtain heteroatom-doped 3D carbon material with continuous charge transfer channels, avoiding the freeze-drying process, achieving an orderly arrangement of carbon atoms and masking the fine and deep inner pores.
It improves the performance of electrochemical sensors, enhances signal amplification capabilities, reduces the masking of the response signal by the charging and discharging process, and improves the construction and performance of the sensor.
Smart Images
Figure CN119595722A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of electrochemical sensors, and in particular to a method for constructing an electrochemical sensor of biomass three-dimensional graphene. Background Art
[0002] Biomass three-dimensional carbon materials are currently one of the hot research topics in the field of electrochemistry, but are more concentrated in the energy field, mainly utilizing their abundant pores and large specific surface area. Tofu-based or egg-based materials, as important precursor materials, are widely used to prepare various low-dimensional nanocarbon materials.
[0003] Biomass three-dimensional carbon materials have the characteristics of three-dimensional continuity of charge transfer channels and highly rough surface. Among them, the continuous three-dimensional charge transfer channel can significantly reduce the charge transfer resistance, thereby realizing signal amplification. The highly rough surface is conducive to the increase of surface active sites, which is also conducive to signal amplification. This rough structure is the embodiment of the internal three-dimensional structure of the material itself extended to the surface. It has a high degree of controllability, uniformity and microstructural stability, and is superior to the irregular rough surface obtained by simple stacking to a certain extent.
[0004] However, although the abundant pores and large specific surface area of biomass three-dimensional carbon materials are conducive to the amplification of electrochemical signals, the large number of fine and deep pores and the complex pore size distribution that is difficult to control will affect the mass transfer in the sensing process, and then affect the electrochemical response signal. The electrochemical response information is easily masked by the significant charging and discharging process, which is not conducive to the construction of the sensor.
[0005] Therefore, it is necessary to invent a method for constructing an electrochemical sensor of biomass three-dimensional graphene to solve the above problems. Summary of the invention
[0006] The purpose of the present invention is to provide a method for constructing an electrochemical sensor of biomass three-dimensional graphene, which utilizes the rich oxygen-containing functional groups of tofu-based or egg-based materials to regulate the cross-linking structure of the precursor, and utilizes the multi-step carbonization and collapse process induced by the cross-linking structure to obtain a heteroatom-doped 3D carbon material with a continuous charge transfer channel. The process avoids processes such as freeze-drying, realizes the orderly arrangement of carbon atoms in the self-collapse carbonization process of the skeleton structure, and simultaneously masks the internal fine and deep channels, thereby improving the performance of the electrochemical sensor, so as to solve the problem that the rich channels and large specific surface area of the biomass three-dimensional carbon material proposed in the above background technology are conducive to the amplification of electrochemical signals, but a large number of fine and deep channels and difficult to control complex pore size distribution will affect the mass transfer in the sensing process, thereby affecting the electrochemical response signal, and the electrochemical response information is easily masked by a significant charge and discharge process, which is not conducive to the construction of the sensor.
[0007] To achieve the above object, the present invention provides the following technical solution: a method for constructing an electrochemical sensor of biomass three-dimensional graphene, specifically comprising the following steps:
[0008] S1. Preparation of 3D carbon materials based on tofu or egg;
[0009] S2. Considering the fact that 3D carbon materials are rich in cellulose, tofu-based or egg-based biomass graphene is obtained by adjusting the pyrolysis process and adding Fe-based catalysts;
[0010] S3, preparing a cross-linked tofu-based or egg-based biomass graphene skeleton structure based on tofu-based or egg-based biomass graphene;
[0011] S4, introducing a heteroatom dopant during the crosslinking process, wherein the heteroatom dopant includes an amide and a borane heteroatom dopant to obtain a heteroatom-doped carbon material;
[0012] S5. Functionalization of heteroatom-doped carbon materials by covalent modification, electrostatic adsorption, self-assembly and π-π conjugation to change the chemical environment on the surface of heteroatom-doped carbon materials, thereby regulating the coordination ability of heteroatom-doped carbon materials and achieving efficient loading of catalytic active sites;
[0013] S6. Construct an electrochemical sensor.
[0014] Preferably, the S1 specifically comprises the following steps:
[0015] The oxygen-containing groups rich in tofu-based or egg-based cellulose are used to induce its cross-linking to form a three-dimensional skeleton with high controllability to achieve the first collapse, and then part of the water in the three-dimensional skeleton is removed to form a stable 3D structure.
[0016] Preferably, the S1 further comprises the following steps:
[0017] The three-dimensional skeleton is hydrothermally pre-carbonized to cause carbonization and shrinkage of the three-dimensional skeleton. During this process, the type, pressure and temperature of the solution are regulated to achieve controllable slow collapse under the induction of a stable three-dimensional skeleton.
[0018] Preferably, the S1 further comprises the following steps:
[0019] By completing high-temperature carbonization and controllable collapse, the three-dimensional skeleton forms a dense 3D network structure to produce 3D carbon materials.
[0020] Preferably, the S3 specifically includes the following steps:
[0021] Organic small molecules are used to induce the gelation of tofu-based or egg-based biomass graphene to obtain a cross-linked tofu-based or egg-based biomass graphene skeleton structure. During this process, the gel inducer occupies the active sites on the graphene surface, and then controls the heteroatom doping position and doping amount in the subsequent reduction doping process.
[0022] Preferably, the S3 specifically includes the following steps:
[0023] The welding of conductive polymer to tofu-based or egg-based biomass graphene is achieved through in-situ initiation to obtain a cross-linked tofu-based or egg-based biomass graphene skeleton structure. The conductive polymer includes pyrrole and EDOT. The pyrrole and EDOT monomers are highly enriched at the cross-linking points, thereby achieving effective welding of the cross-linking points of the carbon material and introducing additional charge transfer channels to assist the tofu-based or egg-based biomass graphene skeleton in constructing a fast charge transfer channel.
[0024] Preferably, the S3 specifically includes the following steps:
[0025] During the pyrolysis process of preparing tofu-based or egg-based biomass graphene, transition metal oxides and sulfides are in situ loaded to obtain a cross-linked tofu-based or egg-based biomass graphene skeleton structure. The metal oxides and sulfides serve as catalytic active sites while providing additional rigid steric hindrance, thereby regulating the 3D structure during the self-collapse of the carbon skeleton.
[0026] Preferably, the S6 specifically comprises the following steps:
[0027] By utilizing the characteristics of heteroatom-doped carbon materials, functional materials or biological molecules with special recognition and catalytic properties are introduced. Through the constructed continuous charge transfer channel, the rapid transfer of charges between the active centers of the introduced components and the electrode substrate is achieved, so as to complete the selective quantitative detection of target pollutants.
[0028] Preferably, the S6 further comprises the following steps:
[0029] The corresponding interferents appearing in the actual detection are masked by alkylation or introduction of anti-interference components, wherein the anti-interference components include polyimide film and peroxidized polypyrrole film, so as to optimize the electrochemical performance and mechanical performance.
[0030] Preferably, the S6 further comprises the following steps:
[0031] The carbon cage structure is formed by the collapse process of the three-dimensional skeleton, and the internal reference element used for sensing is evenly distributed in the three-dimensional channels of the three-dimensional skeleton. The carbon cage is formed through a controllable collapse process to achieve efficient and direct contact between the charge transfer channel and the internal reference element, thereby realizing direct charge transfer.
[0032] Technical effects and advantages of the present invention:
[0033] The present invention utilizes the oxygen-containing groups rich in cellulose in tofu or egg bases, and designs a biomass precursor with a specific structure by adjusting the cross-linking process, thereby adjusting the structure of the pyrolysis 3D carbon material;
[0034] The present invention is based on tofu-based or egg-based biomass graphene, and obtains a 3D carbon material with a three-dimensional continuous interior and a rough surface by a controllable collapse method, avoiding the thin and deep channels and loose skeleton of traditional 3D carbon materials, so that it is more suitable for the construction of electrochemical sensors;
[0035] The present invention explores the effect of heteroatom doping of carbon materials on the structural collapse process, as well as the effect of heteroatom doping on the electrochemical catalytic performance of various target analytes, so that it can be applied in a targeted manner to the detection of various environmental pollutants, and to a certain extent expand the application of heteroatom-doped carbon materials.
[0036] In summary, the present invention utilizes the rich oxygen-containing functional groups of tofu-based or egg-based materials to regulate the cross-linking structure of the precursor, and utilizes the multi-step carbonization and collapse process induced by the cross-linking structure to obtain a heteroatom-doped 3D carbon material with a continuous charge transfer channel. This process avoids processes such as freeze-drying, realizes the orderly arrangement of carbon atoms in the self-collapse carbonization process of the skeleton structure, and simultaneously masks the internal fine and deep channels, thereby improving the performance of the electrochemical sensor. BRIEF DESCRIPTION OF THE DRAWINGS
[0037] Figure 1 It is a schematic diagram of the overall process of the present invention. DETAILED DESCRIPTION
[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0039] Example 1
[0040] The present invention provides a method for constructing an electrochemical sensor of biomass three-dimensional graphene, which specifically comprises the following steps:
[0041] S1. Preparation of 3D carbon materials based on tofu or egg;
[0042] Specifically: using the oxygen-containing groups rich in tofu-based or egg-based cellulose to induce cross-linking, forming a three-dimensional skeleton with high controllability to achieve the first collapse, and then removing part of the water in the three-dimensional skeleton to form a stable 3D structure;
[0043] The three-dimensional skeleton is hydrothermally pre-carbonized to cause carbonization and shrinkage of the three-dimensional skeleton. During this process, the type of solution, pressure and temperature are regulated to achieve controllable slow collapse under the induction of a stable three-dimensional skeleton, rather than structural collapse under rapid carbonization and rapid gas production;
[0044] Complete high-temperature carbonization and controllable collapse to form a dense 3D network structure of the three-dimensional skeleton to obtain 3D carbon materials;
[0045] At this time, a large number of rough microstructures will be generated on the surface of the 3D carbon material to form an obvious steric hindrance effect, avoiding complete densification during the collapse process. Moreover, due to the multi-stage collapse, a high-strength dense skeleton is formed, which can avoid random disintegration during high-temperature carbonization.
[0046] The application of this 3D carbon material in water treatment can be used as an advanced adsorption material to remove harmful heavy metal ions (such as lead, cadmium, mercury, etc.) and organic pollutants (such as pesticides and dyes) in water bodies. Its unique three-dimensional structure and high surface area can provide more adsorption sites and improve the efficiency and treatment capacity of water treatment. In addition, this material can also be used in the sludge dewatering process to improve the efficiency of sludge treatment by enhancing the mechanical strength and structural stability of the sludge.
[0047] S2. Considering the fact that 3D carbon materials are rich in cellulose, tofu-based or egg-based biomass graphene is obtained by adjusting the pyrolysis process and adding Fe-based catalysts;
[0048] The combination of Fe-based catalysts and tofu-based or egg-based biomass graphene can significantly improve its electrochemical activity in sewage treatment, especially in advanced oxidation processes (such as Fenton reaction), which can effectively degrade persistent organic pollutants in water. The high conductivity and large surface area of graphene make it an excellent electrode material, improving the performance of sewage treatment equipment, extending its service life and reducing operating costs.
[0049] S3, using organic small molecules to induce gelation of tofu-based or egg-based biomass graphene to obtain a cross-linked tofu-based or egg-based biomass graphene skeleton structure, during which the gel inducer occupies the active sites on the graphene surface, and then controls the heteroatom doping position and doping amount in the subsequent reduction doping process;
[0050] The cross-linked tofu-based or egg-based biomass graphene skeleton structure can be used as an efficient catalyst carrier in the sewage treatment system to support and stabilize other active substances and enhance the catalytic efficiency. In the water treatment reactor, this structure can improve the mass transfer efficiency and reduce the risk of clogging. It is suitable for treating sewage containing complex organic matter and suspended particles. Its stable skeleton structure can also maintain high efficiency in long-term use and reduce maintenance costs.
[0051] S4, introducing a heteroatom dopant during the crosslinking process, wherein the heteroatom dopant includes an amide and a borane heteroatom dopant to obtain a heteroatom-doped carbon material;
[0052] The type of heteroatoms and doping sites are sensitive to the doping process. For different environmental pollutants, the doping amount and doping form can be highly controlled by adjusting the crosslinking conditions and dopants.
[0053] The application of heteroatom-doped (such as nitrogen, boron, etc.) carbon materials in water treatment can greatly improve their electrochemical performance, making them ideal materials for electrocatalytic degradation of organic pollutants (such as antibiotics, dyes, etc.) and reduction of heavy metal ions. This modified material can effectively improve the stability and reaction selectivity of electrodes in the sewage treatment process, reduce the incidence of side reactions, and improve the overall efficiency of sewage treatment.
[0054] S5. Functionalization of heteroatom-doped carbon materials by covalent modification, electrostatic adsorption, self-assembly and π-π conjugation to change the chemical environment on the surface of heteroatom-doped carbon materials, thereby regulating the coordination ability of heteroatom-doped carbon materials and achieving efficient loading of catalytic active sites;
[0055] Functionalization of heteroatom-doped carbon materials can further enhance their selectivity and adsorption capacity for specific pollutants, which is particularly suitable for the removal of specific pollutants (such as phosphate and ammonia nitrogen) during sewage treatment. By introducing specific functional groups, the materials can also be endowed with anti-biological pollution properties, extending the operating life of the treatment equipment and improving the overall stability of the water treatment system.
[0056] S6. Utilizing the characteristics of heteroatom-doped carbon materials, functional materials or biomolecules with special recognition and catalytic properties are introduced, and the rapid transfer of charges between the active centers of the introduced components and the electrode substrate is achieved through the constructed continuous charge transfer channel, so as to complete the selective quantitative detection of target pollutants;
[0057] The corresponding interference substances appearing in the actual detection are masked by alkylation or introduction of anti-interference components, wherein the anti-interference components include polyimide film and peroxidized polypyrrole film, so as to optimize the electrochemical performance and mechanical performance;
[0058] The water quality detection system based on this electrochemical sensor can monitor the key parameters such as heavy metal ions, pesticide residues, organic pollutants in the water in real time to ensure the effectiveness and safety of the water treatment process. The high sensitivity and rapid response capability of the sensor enable it to detect the concentration changes of pollutants in a timely manner and provide instant feedback, which is conducive to the control and optimization of the automated water treatment system.
[0059] In sewage treatment detection systems, this sensor can be used to accurately measure the concentration of specific pollutants (such as organic dyes and heavy metals), thereby helping to adjust treatment process parameters (such as the amount of chemical reagents added or the electrolysis conditions), optimize treatment effects, and reduce resource waste. It can also be used for outlet monitoring of separation systems to ensure that the treated water meets the quality standards.
[0060] Example 2
[0061] Different from the above embodiment, S3 specifically includes:
[0062] The welding of conductive polymer to tofu-based or egg-based biomass graphene is achieved through in-situ initiation to obtain a cross-linked tofu-based or egg-based biomass graphene skeleton structure. The conductive polymer includes pyrrole and EDOT. The pyrrole and EDOT monomers are highly enriched at the cross-linking points, thereby achieving effective welding of the cross-linking points of the carbon material and introducing additional charge transfer channels to assist the tofu-based or egg-based biomass graphene skeleton in constructing a fast charge transfer channel.
[0063] Example 3
[0064] Different from the above embodiment, S3 specifically includes:
[0065] During the pyrolysis process of preparing tofu-based or egg-based biomass graphene, transition metal oxides and sulfides are in situ loaded to obtain a cross-linked tofu-based or egg-based biomass graphene skeleton structure. The metal oxides and sulfides serve as catalytic active sites while providing additional rigid steric hindrance, thereby regulating the 3D structure during the self-collapse of the carbon skeleton.
[0066] Example 4
[0067] Different from the above embodiment, S6 specifically includes:
[0068] The carbon cage structure is formed by the collapse process of the three-dimensional skeleton, and the internal reference element used for sensing is evenly distributed in the three-dimensional pores of the three-dimensional skeleton. The carbon cage is formed through a controllable collapse process to achieve efficient direct contact between the charge transfer channel and the internal reference element, thereby achieving direct charge transfer.
[0069] This carbon cage structure can be used as a carrier of efficient catalysts or adsorbents in water treatment applications, enhancing the electrochemical stability and reaction rate of the material. Its unique three-dimensional pore design helps to increase the contact area between reactants and catalysts and promote the degradation of pollutants. In addition, the structure can also enhance the performance of the sensor and ensure long-term stable electrochemical signal output, making it suitable for online monitoring of sewage treatment systems.
[0070] In sewage treatment detection systems, this design can ensure the high efficiency and accuracy of the sensor, especially in complex and changeable sewage environments. The carbon cage structure not only improves the mechanical strength of the material, but also optimizes the kinetic characteristics of the electrochemical reaction, and can maintain stable detection performance in harsh environments. It is suitable for online monitoring systems of industrial wastewater treatment plants, which helps to detect water quality abnormalities in a timely manner and take corresponding measures.
[0071] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.
Claims
1. A method for constructing an electrochemical sensor of biomass three-dimensional graphene, characterized in that: The specific steps include: S1. Preparation of 3D carbon materials based on tofu or egg; S2. Considering the fact that 3D carbon materials are rich in cellulose, tofu-based or egg-based biomass graphene is obtained by adjusting the pyrolysis process and adding Fe-based catalysts; S3, preparing a cross-linked tofu-based or egg-based biomass graphene skeleton structure based on tofu-based or egg-based biomass graphene; S4, introducing a heteroatom dopant during the crosslinking process, wherein the heteroatom dopant includes an amide and a borane heteroatom dopant to obtain a heteroatom-doped carbon material; S5. Functionalization of heteroatom-doped carbon materials by covalent modification, electrostatic adsorption, self-assembly and π-π conjugation to change the chemical environment on the surface of heteroatom-doped carbon materials, thereby regulating the coordination ability of heteroatom-doped carbon materials and achieving efficient loading of catalytic active sites; S6. Construct an electrochemical sensor.
2. The method for constructing an electrochemical sensor of biomass three-dimensional graphene according to claim 1, characterized in that: The S1 specifically includes the following steps: The oxygen-containing groups rich in tofu-based or egg-based cellulose are used to induce its cross-linking to form a three-dimensional skeleton with high controllability to achieve the first collapse, and then part of the water in the three-dimensional skeleton is removed to form a stable 3D structure.
3. The method for constructing a biomass three-dimensional graphene electrochemical sensor according to claim 2, characterized in that: The S1 specifically further comprises the following steps: The three-dimensional skeleton is hydrothermally pre-carbonized to cause carbonization and shrinkage of the three-dimensional skeleton. During this process, the type, pressure and temperature of the solution are regulated to achieve controllable slow collapse under the induction of a stable three-dimensional skeleton.
4. The method for constructing a biomass three-dimensional graphene electrochemical sensor according to claim 3, characterized in that: The S1 specifically further comprises the following steps: By completing high-temperature carbonization and controllable collapse, the three-dimensional skeleton forms a dense 3D network structure to produce 3D carbon materials.
5. The method for constructing an electrochemical sensor of biomass three-dimensional graphene according to claim 4, characterized in that: The S3 specifically includes the following steps: Organic small molecules are used to induce the gelation of tofu-based or egg-based biomass graphene to obtain a cross-linked tofu-based or egg-based biomass graphene skeleton structure. During this process, the gel inducer occupies the active sites on the graphene surface, and then controls the heteroatom doping position and doping amount in the subsequent reduction doping process.
6. The method for constructing a biomass three-dimensional graphene electrochemical sensor according to claim 5, characterized in that: The S3 specifically includes the following steps: The welding of conductive polymer to tofu-based or egg-based biomass graphene is achieved through in-situ initiation to obtain a cross-linked tofu-based or egg-based biomass graphene skeleton structure. The conductive polymer includes pyrrole and EDOT. The pyrrole and EDOT monomers are highly enriched at the cross-linking points, thereby achieving effective welding of the cross-linking points of the carbon material and introducing additional charge transfer channels to assist the tofu-based or egg-based biomass graphene skeleton in constructing a fast charge transfer channel.
7. The method for constructing a biomass three-dimensional graphene electrochemical sensor according to claim 6, characterized in that: The S3 specifically includes the following steps: During the pyrolysis process of preparing tofu-based or egg-based biomass graphene, transition metal oxides and sulfides are in situ loaded to obtain a cross-linked tofu-based or egg-based biomass graphene skeleton structure. The metal oxides and sulfides serve as catalytic active sites while providing additional rigid steric hindrance, thereby regulating the 3D structure during the self-collapse of the carbon skeleton.
8. The method for constructing a biomass three-dimensional graphene electrochemical sensor according to claim 7, characterized in that: The S6 specifically comprises the following steps: By utilizing the characteristics of heteroatom-doped carbon materials, functional materials or biological molecules with special recognition and catalytic properties are introduced. Through the constructed continuous charge transfer channel, the rapid transfer of charges between the active centers of the introduced components and the electrode substrate is achieved, so as to complete the selective quantitative detection of target pollutants.
9. The method for constructing a biomass three-dimensional graphene electrochemical sensor according to claim 8, characterized in that: The S6 specifically further comprises the following steps: The corresponding interferents appearing in the actual detection are masked by alkylation or introduction of anti-interference components, wherein the anti-interference components include polyimide film and peroxidized polypyrrole film, so as to optimize the electrochemical performance and mechanical performance.
10. The method for constructing a biomass three-dimensional graphene electrochemical sensor according to claim 9, characterized in that: The S6 specifically further comprises the following steps: The carbon cage structure is formed by the collapse process of the three-dimensional skeleton, and the internal reference element used for sensing is evenly distributed in the three-dimensional channels of the three-dimensional skeleton. The carbon cage is formed through a controllable collapse process to achieve efficient and direct contact between the charge transfer channel and the internal reference element, thereby realizing direct charge transfer.