Plant-microbe synergistic power generation method and device

Abstract

The application discloses a kind of plant synergistic microbial power generation methods, including preparation membrane electrode, preparation plant material, electrode and plant tissue coupling, reference electrode connection, circuit connection, microbial inoculation, enhance microbial activity and fuel cell start-up etc., the application gets rid of the dependence on water environment, make the operation of plant power generation greatly reduce the influence of environmental factors, power output is more stable, thereby improve power generation efficiency and reliability.Secondly, the application expands the range of coupled plants.In addition, the application innovatively introduces microporous filter membrane between membrane electrode and plant tissue, optimizes the contact and material exchange between electrode and plant tissue, which helps to improve the performance of electrode and the power generation efficiency of fuel cell.

Description

Technical Field

[0001] This invention relates to the field of microbial fuel cell technology, specifically to a method and apparatus for generating electricity through plant-assisted microbial power generation. Background Technology

[0002] In today's society, with rapid industrialization and urbanization, energy consumption has increased dramatically. While the traditional fossil fuel structure meets energy demands, it has also brought about serious environmental pollution and climate change problems. To address this challenge, the development and utilization of clean energy has become a global focus.

[0003] Plants, as organisms capable of converting light energy into chemical energy through photosynthesis, possess enormous potential for energy development from the organic matter they store. However, most current methods for utilizing plant energy require complex secondary conversion processes, such as high-temperature and high-pressure pyrolysis, chemical treatment, and composting. These methods are not only inefficient in energy conversion but also consume significant amounts of power and energy during the conversion process, while also negatively impacting food production, arable land, forest area, and agricultural resources and the environment.

[0004] Microbial fuel cells, as an emerging energy conversion device, can use microorganisms as catalysts to directly convert organic substrates into electrical energy, offering advantages such as high efficiency and environmental friendliness. Combining plants with microbial fuel cells to construct a plant-microorganism fuel cell system enables the direct utilization of organic matter within plants, avoiding the various drawbacks of traditional methods.

[0005] However, most existing plant-microbe fuel cell systems couple electrochemically active microorganisms with plant roots. This approach is primarily suitable for aquatic plants such as rice, calamus, water hyacinth, and mosses, but has significant limitations for a wide range of terrestrial plants. Furthermore, root coupling is an external coupling method, making it susceptible to environmental factors such as moisture, temperature, light, humidity, and salinity, leading to unstable operation and large fluctuations in power output of plant-microbe fuel cells. Summary of the Invention

[0006] The purpose of this invention is to solve the above-mentioned technical problems and provide a plant-co-microorganism power generation method, which not only expands the range of plant species that can be coupled, but also improves power generation efficiency and reliability.

[0007] To solve the above problems, the present invention is implemented according to the following technical solution:

[0008] In a first aspect, the present invention provides a method for plant-assisted microbial power generation, the method comprising the following steps:

[0009] (1) Preparation of membrane electrode: The first conductive carbon material, the ion exchange membrane and the second conductive carbon material are arranged in sequence and then hot-pressed to form a membrane electrode;

[0010] (2) Preparation of plant materials: After cutting open the epidermis of the stem or root of the plant to form a naked plant tissue area, cover the surface of the naked plant tissue area with a microporous filter membrane.

[0011] (3) Coupling of the electrode with plant tissue: The membrane electrode is attached to the plant tissue area covered with the microporous filter membrane, and a silicone pad is placed on the cathode surface of the membrane electrode to fix the membrane electrode.

[0012] (4) Reference electrode connection: Prepare two syringe needles and one Luggin capillary. Connect one end of the Luggin capillary to the reference electrode. After embedding the other end of the Luggin capillary and the two syringe needles between the exposed plant tissue area and the anode of the membrane electrode, seal and fix the embedded Luggin capillary and syringe needles with silicone.

[0013] (5) Circuit connection: Connect the anode, cathode and external circuit load of the membrane electrode with titanium wire so that the current generated by the membrane electrode can flow to the load;

[0014] (6) Microbial inoculation: Electrochemically active microbial strains are injected into the area between the exposed plant tissue and the anode of the membrane electrode through the syringe needle for inoculation. After inoculation, the needle is sealed with a rubber stopper.

[0015] (7) Enhance microbial activity: Inject a solution of a certain concentration containing an organic carbon source that can be metabolized by electrochemically active microorganisms into the anode of the membrane electrode to enhance the activity of microorganisms in the anode region;

[0016] (8) Fuel cell startup: After 2 to 4 days of continuous microbial inoculation in step (6), the startup of the fuel cell for plant-co-microbial power generation is completed.

[0017] Preferably, in step (1), the first conductive carbon material is one of carbon paper, carbon felt, carbon fiber or graphite; the second conductive carbon material is one of carbon paper, carbon felt, carbon fiber or graphite; and the ion exchange membrane in step (1) is one of cation exchange membrane, anion exchange membrane or proton exchange membrane.

[0018] Preferably, the first conductive carbon material and the second conductive carbon material are platinum-modified materials, nanoparticle-modified materials, or materials modified with other chemical reagents.

[0019] Preferably, in step (1), the temperature during hot pressing is 100-180°C, the pressure during hot pressing is 6-9 MPa, and the hot pressing time is 1-20 min.

[0020] Preferably, in step (2), the exposed plant tissue area includes xylem, phloem, inner bark, roots, and inner plant cells of branches and leaves.

[0021] Preferably, in step (4), the outer surfaces of the two syringe needles are coated with polyvinyl chloride material.

[0022] Preferably, in step (4), the reference electrode is either an Ag / AgX composite reference electrode or a saturated calomel reference electrode.

[0023] Preferably, in step (6), the electrochemically active microbial species include Geobacterium and Shewanella.

[0024] Preferably, in step (7), the solution containing an organic carbon source that can be metabolized by electrochemically active microorganisms at a certain concentration contains 0.3–1.5 g / L of organic carbon source. -1 Physiological saline solution containing 0.3–1.5 g / L glucose -1 Fructose in physiological saline or containing 0.3–1.5 g / L -1 Lactic acid is one of the components of physiological saline.

[0025] Secondly, the present invention provides a plant-synergistic microbial power generation device, which is used to implement the aforementioned plant-synergistic microbial power generation method, the device comprising:

[0026] An experimental plant having exposed plant tissue regions covered with a microporous filter membrane;

[0027] A membrane electrode, wherein the membrane electrode is connected to the exposed plant tissue region covered with a microporous filter membrane, the membrane electrode comprising an anode, an ion exchange membrane, and a cathode;

[0028] A reference electrode, which is connected between the exposed plant tissue region and the anode via a Luggin capillary tube;

[0029] A load, which is connected to the anode and cathode via wires;

[0030] In this method, two syringe needles are inserted between the exposed plant tissue area and the anode to inoculate microorganisms.

[0031] Compared with the prior art, the beneficial effects of the present invention are:

[0032] This invention provides a method and apparatus for plant-assisted microbial power generation. Firstly, by embedding electrodes within the plant tissue and tightly coupling them, a novel method and apparatus for plant-assisted microbial power generation is constructed. Compared to traditional plant-microbial fuel cell systems, this approach eliminates dependence on the aquatic environment, significantly reducing the impact of environmental factors on plant power generation and resulting in more stable power output, thereby improving power generation efficiency and reliability. Secondly, this invention expands the range of compatible plant species, applicable not only to aquatic plants but also to terrestrial plants such as trees and shrubs, greatly enriching the sources of plant energy utilization and providing more possibilities for plant energy development in different ecological environments. Furthermore, this invention innovatively introduces a microporous membrane between the membrane electrode and plant tissue, optimizing the contact and material exchange between the electrode and plant tissue, which helps improve electrode performance and fuel cell power generation efficiency. Simultaneously, this invention also effectively enhances the activity of microorganisms in the anode region by injecting a solution of a certain concentration containing organic carbon sources that can be metabolized by electrochemically active microorganisms, further improving the power generation performance of the fuel cell. Finally, the device of the present invention has a simple structure, is easy to operate, and is easy to implement and promote. It has high practical value and market prospects, and provides a new technical approach for achieving green and sustainable energy development and utilization. Attached Figure Description

[0033] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings, wherein:

[0034] Figure 1 This is a schematic diagram of the structure of a plant-assisted microbial power generation device according to the present invention;

[0035] Figure 2 This is a schematic diagram of the electrode composition of a plant-co-microorganism power generation device according to the present invention;

[0036] In the picture:

[0037] 1-Experimental plant, 2-Membrane electrode, 3-Load, 4-Wire, 5-Exposed plant tissue area, 6-Microporous filter membrane, 7-Anode, 8-Ion exchange membrane, 9-Cathode, 10-Microorganism. Detailed Implementation

[0038] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0039] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. Unless otherwise defined, the technical or scientific terms used in this specification should have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar words used in this specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different technical features.

[0040] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0041] like Figures 1-2 As shown, the present invention discloses a plant-assisted microbial power generation method, which includes the following steps:

[0042] (1) Preparation of membrane electrode: The first conductive carbon material, the ion exchange membrane and the second conductive carbon material are arranged in sequence and then hot-pressed to form a membrane electrode.

[0043] Preferably, in step (1), the first conductive carbon material is one of carbon paper, carbon felt, carbon fiber, or graphite; the second conductive carbon material is one of carbon paper, carbon felt, carbon fiber, or graphite. Because conductive carbon materials such as carbon paper, carbon felt, carbon fiber, and graphite have good conductivity and a large specific surface area, they are conducive to the attachment of electrochemically active microorganisms and the transfer of electrons, thereby improving the activity and stability of the electrode and enhancing the performance of the fuel cell.

[0044] In a preferred embodiment, the first conductive carbon material and the second conductive carbon material are platinum-modified materials, nanoparticle-modified materials, or materials modified with other chemical reagents. Specifically, the first conductive carbon material can be one of the following: platinum-modified carbon paper, nanoparticle-modified carbon paper, carbon paper modified with other chemical reagents, platinum-modified carbon felt, nanoparticle-modified carbon felt, carbon felt modified with other chemical reagents, platinum-modified carbon fiber, nanoparticle-modified carbon fiber, carbon fiber modified with other chemical reagents, platinum-modified graphite, nanoparticle-modified graphite, or graphite modified with other chemical reagents. Similarly, the second conductive carbon material can be one of the following: platinum-modified carbon paper, nanoparticle-modified carbon paper, carbon paper modified with other chemical reagents, platinum-modified carbon felt, nanoparticle-modified carbon felt, carbon felt modified with other chemical reagents, platinum-modified carbon fiber, nanoparticle-modified carbon fiber, carbon fiber modified with other chemical reagents, platinum-modified graphite, nanoparticle-modified graphite, or graphite modified with other chemical reagents.

[0045] It should be noted that platinum (Pt) is a noble metal with excellent catalytic properties, which can significantly improve the catalytic activity of electrodes. At the anode, Pt modification can promote the electron transfer process of electrochemically active microorganisms (EABs), enabling electrons generated by the oxidation of organic matter by microorganisms to be more effectively transferred to the electrode, thereby increasing the anode current output. At the cathode, Pt modification can accelerate the oxygen reduction reaction (ORR), reduce the charge transport impedance of the cathode, improve the electrochemical performance of the cathode, and thus enhance the power density and energy conversion efficiency of the entire fuel cell. Nanoparticles possess high specific surface area and unique physicochemical properties, providing electrodes with more active sites and larger contact areas. For example, nanoparticle-modified materials (such as carbon nanotubes and graphene nanosheets) can enhance the conductivity and mechanical strength of electrodes, while providing a better attachment and growth environment for electrochemically active microorganisms, which is beneficial to their metabolic activities and electron transfer. Furthermore, electrodes modified with some metal nanoparticles (such as gold nanoparticles and silver nanoparticles) can also improve the catalytic activity and selectivity of the electrode, promoting specific electrochemical reactions. Modification with other chemical reagents, such as conductive polymers (e.g., polypyrrole, polyaniline), can improve the conductivity and stability of the electrode, while providing a favorable biocompatibility environment for electrochemically active microorganisms, which is beneficial for their long-term growth and stable operation. In summary, these preferred modification methods can effectively improve the performance of the prepared membrane electrode, enhancing the power generation efficiency and stability of plant-microbe fuel cells.

[0046] Preferably, in step (1), the ion exchange membrane is one of a cation exchange membrane, anion exchange membrane, or proton exchange membrane. In practical applications, selecting a suitable membrane material based on the actual situation can optimize ion transport and electrochemical reaction environment between electrodes, thereby improving the energy conversion efficiency of the fuel cell.

[0047] Preferably, in step (1), the temperature during hot pressing is 100–180°C, the pressure during hot pressing is 6–9 MPa, and the hot pressing time is 1–20 min. This ensures that the membrane electrode has a compact structure and good interfacial bonding, while avoiding excessive carbonization or damage to the material, thus giving the membrane electrode excellent mechanical and electrochemical properties.

[0048] (2) Preparation of plant materials: After cutting open the epidermis of the stem or root of the plant to form a naked plant tissue area, cover the surface of the naked plant tissue area with a microporous filter membrane.

[0049] Understandably, cutting open the epidermis of the plant's stem or root and exposing the plant tissue area provides space and contact surface for the coupling of the membrane electrode and the inoculation of electrochemically active microorganisms, enabling the organic matter in the plant to be utilized by microorganisms more effectively, thereby improving the power generation efficiency of the fuel cell.

[0050] It should be noted that the microporous membrane can filter out large particles in plant tissue, preventing them from clogging the electrode surface, while allowing small organic molecules and ions to pass through smoothly. This invention coats the exposed plant tissue area with a microporous membrane, optimizing the contact environment between the electrode and the plant tissue and improving electrode performance.

[0051] Preferably, in step (2), the exposed plant tissue areas include xylem, phloem, inner bark, roots, and inner plant cells of branches and leaves. These areas are rich in organic matter produced by plant photosynthesis, which is an important source of energy and nutrition for microorganisms, thus promoting their growth and electricity generation.

[0052] (3) Electrode coupling with plant tissue: The membrane electrode is attached to the plant tissue area covered by the microporous filter membrane, and a silicone pad is placed on the cathode surface of the membrane electrode to fix the membrane electrode.

[0053] It should be noted that attaching the membrane electrode to the plant tissue area covered by the microporous filter membrane and fixing it with a silicone pad can ensure that the membrane electrode is tightly bonded to the plant tissue, ensuring unimpeded material exchange and electron transfer between the electrode and the plant tissue, while preventing leakage of electrolyte or microorganisms and ensuring the stable operation of the fuel cell.

[0054] Preferably, in step (3), the silicone pad is an annular silicone pad. The annular silicone pad can apply pressure evenly, so that the membrane electrode can fit tightly with the plant tissue, and at the same time play a good sealing role, preventing electrolyte or microorganisms from leaking from the edges, thus ensuring the sealing and stability of the fuel cell.

[0055] (4) Reference electrode connection: Prepare two syringe needles and one Luggin capillary. Connect one end of the Luggin capillary to the reference electrode. After embedding the other end of the Luggin capillary and the two syringe needles between the exposed plant tissue area and the anode of the membrane electrode, seal and fix the embedded Luggin capillary and syringe needles with silicone.

[0056] It should be noted that a Luggin capillary is a long, thin glass tube with one end connected to the reference electrode and the other end close to the electrode surface. In electrochemical measurements, using a Luggin capillary reduces the distance between the electrode and the reference electrode, thereby reducing the influence of solution resistance on the measurement results and improving the accuracy of potential measurement. This is because solution resistance causes a potential drop, which in turn causes the measured potential to deviate from the true electrode potential. This invention introduces the reference electrode between the exposed plant tissue region and the anode of the membrane electrode assembly using a Luggin capillary, providing a stable reference point for accurate electrode potential measurement. This helps monitor the operating status of the fuel cell and optimize electrode materials and operating conditions.

[0057] Preferably, in step (4), the outer surfaces of the two syringe needles are coated with polyvinyl chloride (PVC) material. Because PVC material has good sealing properties and chemical stability, it can prevent electrolyte or microorganisms from leaking from the gap between the needle and the plant tissue, ensuring the reliability and stability of the reference electrode connection.

[0058] Preferably, in step (4), the reference electrode is either an Ag / AgX composite reference electrode or a saturated calomel reference electrode.

[0059] (5) Circuit connection: Connect the anode, cathode and load of the membrane electrode to the load of the external circuit using titanium wire so that the current generated by the membrane electrode can flow to the load.

[0060] It should be noted that connecting the anode, cathode, and external circuit load of the membrane electrode assembly (MEA) with titanium wire forms a complete electrochemical circuit, enabling the current generated by the MEA to flow smoothly to the load, thus achieving efficient output and utilization of electrical energy. This is a crucial step in realizing the power generation function of a fuel cell. Titanium wire possesses excellent conductivity and mechanical properties, ensuring the stability and reliability of the circuit connection while avoiding energy loss caused by excessive resistance at the circuit connection points, thereby improving the energy conversion efficiency of the fuel cell.

[0061] (6) Microbial inoculation: Electrochemically active microbial strains are injected into the area between the exposed plant tissue and the anode of the membrane electrode through the syringe needle for inoculation. After inoculation, the needle is sealed with a rubber stopper.

[0062] Understandably, electrochemically active microbial strains are injected into the area between the exposed plant tissue and the anode of the membrane electrode using a syringe needle. This allows the microorganisms to grow and reproduce on the anode surface, metabolize organic matter within the plant, and generate electrons, thereby initiating the power generation process of the fuel cell.

[0063] It should be noted that sealing the needle with a rubber stopper after inoculation can prevent the inoculated microbial solution from overflowing or becoming contaminated, ensuring the accuracy and effectiveness of microbial inoculation and providing a guarantee for the smooth start-up and stable operation of the fuel cell.

[0064] Preferably, in step (6), the electrochemically active microbial species include Geobacterium and Shewanella.

[0065] It should be noted that *Geobacter* and *Shewanella*, as electrochemically active microbial species, can directly transfer electrons to the electrode with their highly efficient electron transport capabilities. They enhance microbial attachment and growth on the electrode surface by forming stable biofilms, and possess broad substrate metabolic capabilities, utilizing various organic substances provided by plants for metabolism, thereby generating electricity. Their strong environmental adaptability allows the system to operate stably under different conditions and may promote plant growth and environmental remediation through metabolic activities. They provide a solid foundation for the application of the plant-co-microbial power generation technology of this invention, making it an efficient, stable, and environmentally friendly energy conversion solution. In this invention, suspensions of these two bacteria can be injected during inoculation. A suspension refers to bacteria cultured in a suitable culture medium; after a certain period of cultivation, the bacteria will multiply and form a suspension. During inoculation, this suspension is injected into the interface between the anode region of the membrane electrode and the plant tissue using a syringe needle. In this way, the bacteria can attach to the anode surface and begin to grow, utilizing the organic matter provided by the plant for metabolism and generating electrons.

[0066] (7) Enhance microbial activity: Inject a solution of a certain concentration containing organic carbon source that can be metabolized by electrochemically active microorganisms into the anode of the membrane electrode to enhance the activity of microorganisms in the anode region.

[0067] Preferably, in step (7), the solution containing an organic carbon source that can be metabolized by electrochemically active microorganisms at a certain concentration contains 0.3–1.5 g / L of organic carbon source. -1 Physiological saline solution containing 0.3–1.5 g / L glucose -1 Fructose in physiological saline or containing 0.3–1.5 g / L -1 Lactic acid is one of the components of physiological saline. Because organic carbon sources such as glucose, fructose, and lactic acid are commonly used metabolic substrates for electrochemically active microorganisms, it contains 0.3–1.5 g / L. -1 Physiological saline solutions containing these organic carbon sources at appropriate concentrations can meet the growth needs of microorganisms while avoiding excessive metabolic burden or inhibition of their activity caused by excessively high concentrations, thus allowing microorganisms to perform optimally in a suitable environment.

[0068] In a preferred embodiment, the injection flow rate for injecting a solution containing an organic carbon source that can be metabolized by electrochemically active microorganisms at a certain concentration into the anode of the membrane electrode is 0.05–0.1 mL / h. -1 .

[0069] (8) Fuel cell startup: After 2 to 4 days of continuous microbial inoculation in step (6), the startup of the fuel cell for plant-co-microbial power generation is completed.

[0070] Understandably, by continuously inoculating microorganisms, a stable biofilm is formed on the anode surface, which enhances the electron transfer efficiency between the electrode and the microorganisms. At the same time, the metabolic products of the microorganisms can also promote the growth and development of plants, realizing the synergistic effect between plants and microorganisms, and improving the overall performance and application value of fuel cells.

[0071] In a preferred embodiment, the open-circuit voltage of the fuel cell for plant-assisted microbial power generation after startup is 0.3–0.4 V, and the maximum power density is 3–8 mW / m³. -2 Anode area.

[0072] The present invention also provides a plant-synergistic microbial power generation device, which is used to implement the plant-synergistic microbial power generation method described in any one of the claims, the device comprising:

[0073] An experimental plant having exposed plant tissue regions covered with a microporous filter membrane;

[0074] A membrane electrode, wherein the membrane electrode is connected to the exposed plant tissue region covered with a microporous filter membrane, the membrane electrode comprising an anode, an ion exchange membrane, and a cathode;

[0075] A reference electrode, which is connected between the exposed plant tissue region and the anode via a Luggin capillary tube;

[0076] A load, which is connected to the anode and cathode via wires;

[0077] In this method, two syringe needles are inserted between the exposed plant tissue area and the anode to inoculate microorganisms.

[0078] Preferably, the wires connecting the load, the anode, and the cathode are titanium wires.

[0079] Compared with the prior art, the beneficial effects of the present invention are:

[0080] This invention provides a method and apparatus for plant-assisted microbial power generation. Firstly, by embedding electrodes within the plant tissue and tightly coupling them, a novel method and apparatus for plant-assisted microbial power generation is constructed. Compared to traditional plant-microbial fuel cell systems, this approach eliminates dependence on the aquatic environment, significantly reducing the impact of environmental factors on plant power generation and resulting in more stable power output, thereby improving power generation efficiency and reliability. Secondly, this invention expands the range of compatible plant species, applicable not only to aquatic plants but also to terrestrial plants such as trees and shrubs, greatly enriching the sources of plant energy utilization and providing more possibilities for plant energy development in different ecological environments. Furthermore, this invention innovatively introduces a microporous membrane between the membrane electrode and plant tissue, optimizing the contact and material exchange between the electrode and plant tissue, which helps improve electrode performance and fuel cell power generation efficiency. Simultaneously, this invention also effectively enhances the activity of microorganisms in the anode region by injecting a solution of a certain concentration containing organic carbon sources that can be metabolized by electrochemically active microorganisms, further improving the power generation performance of the fuel cell. Finally, the device of the present invention has a simple structure, is easy to operate, and is easy to implement and promote. It has high practical value and market prospects, and provides a new technical approach for achieving green and sustainable energy development and utilization.

[0081] In one specific embodiment, the implementation scheme is as follows:

[0082] (1) Preparation of membrane electrode: After placing carbon paper coated with Pt, cation exchange membrane and carbon felt in sequence, hot press is used to press for 20 min at 6 MPa and 170 °C to prepare membrane electrode.

[0083] (2) Preparation of plant material: Cut the epidermis to the phloem of the stem of an indoor potted plant, the money tree, and peel off the bark to form a naked plant tissue area of ​​about 4 cm × 2 cm × 0.5 cm. Cover the surface of the naked plant tissue area with a microporous filter membrane.

[0084] (3) Electrode coupling with plant tissue: The membrane electrode is cut to the same size as the exposed plant tissue, with the carbon paper surface as the cathode and the carbon felt surface as the anode, and embedded in the exposed plant tissue area, and a silicone pad is covered on the cathode surface;

[0085] (4) Reference electrode connection: Connect one end of the Luggin capillary to the reference electrode, and insert the other end of the Luggin capillary and two injection needles dipped in polyvinyl chloride between the phloem and the anode. Seal the injection port with a rubber stopper.

[0086] (5) Circuit connection: Connect the cathode, anode and the 5000Ω load of the external circuit with titanium wire;

[0087] (6) Microbial inoculation: Inoculate the exposed plant tissue area with 2 mL of cultured electrochemically active microbial suspension through the injection needle;

[0088] (7) Inoculate continuously for 3 days, monitor the open circuit voltage until the battery is fully activated;

[0089] The experimental results showed that when the battery was fully started, the open circuit voltage was 0.35 V and the operating voltage was 0.15 V. The fuel cell with plant-co-microorganism power generation did not have a diurnal oscillation effect and operated stably for 40 days.

[0090] In another specific embodiment, the implementation scheme is as follows:

[0091] (1) Preparation of membrane electrode: After placing the carbon felt loaded with Pt nanoparticles, the cation exchange membrane and the carbon felt loaded with Ag nanoparticles in sequence, they were hot-pressed for 5 min at 9 MPa and 180 °C to prepare the membrane electrode.

[0092] (2) Preparation of plant material: Cut the epidermis to the phloem of the stem of an outdoor poplar tree with a knife, peel off the bark to form a naked plant tissue area of ​​about 8 cm × 4 cm × 1 cm. Cut a microfiltration membrane to the same size as the naked part and cover the naked phloem tissue.

[0093] (3) Electrode coupling with plant tissue: The membrane electrode is cut to the same size as the exposed plant tissue area. The carbon felt surface coated with Pt nanoparticles is used as the cathode and the carbon felt surface coated with Ag nanoparticles is used as the anode. It is embedded in the exposed plant tissue area covered with microfiltration membrane and a silicone pad is covered on the cathode surface.

[0094] (4) Reference electrode connection: Connect one end of the Luggin capillary to the reference electrode, and insert the other end of the Luggin capillary and two injection needles dipped in polyvinyl chloride between the phloem and the anode. Seal the injection port with a rubber stopper.

[0095] (5) Circuit connection: Connect the cathode, anode and a battery load of the external circuit with titanium wire;

[0096] (6) Microbial inoculation: 2 mL of cultured electrochemically active microbial suspension of Shewanella was injected into the area between the exposed plant tissue and the anode using an injection needle.

[0097] (7) Inoculate continuously for 3 days, monitor the open circuit voltage until the battery is fully activated;

[0098] The experimental results showed that after full startup, the open-circuit voltage was 0.25 V and the operating voltage was 0.19 V. The fuel cell with plant-co-microorganism power generation did not have a diurnal oscillation effect and operated stably for 60 days.

[0099] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for generating electricity through plant-assisted microbial co-production, characterized in that, The method includes the following steps: (1) Preparation of membrane electrode: After placing the first conductive carbon material, the ion exchange membrane and the second conductive carbon material in sequence, they are hot-pressed to form a membrane electrode; (2) Preparation of plant materials: After cutting open the epidermis of the stem or root of the plant to form a naked plant tissue area, cover the surface of the naked plant tissue area with a microporous filter membrane. (3) Electrode coupling with plant tissue: The membrane electrode is attached to the plant tissue area covered with microporous filter membrane, and a silicone pad is placed on the cathode surface of the membrane electrode to fix the membrane electrode. (4) Reference electrode connection: Prepare two syringe needles and one Luggin capillary. Connect one end of the Luggin capillary to the reference electrode. After embedding the other end of the Luggin capillary and the two syringe needles between the exposed plant tissue area and the anode of the membrane electrode, seal and fix the embedded Luggin capillary and syringe needles with silicone. (5) Circuit connection: Connect the anode, cathode and external circuit load of the membrane electrode with titanium wire so that the current generated by the membrane electrode can flow to the load; (6) Microbial inoculation: Electrochemically active microbial strains are injected into the exposed plant tissue area and the anode of the membrane electrode through the syringe needle for inoculation. After inoculation, the needle is sealed with a rubber stopper. (7) Enhance microbial activity: Inject a solution of a certain concentration containing an organic carbon source that can be metabolized by electrochemically active microorganisms into the anode of the membrane electrode to enhance the activity of microorganisms in the anode region; (8) Fuel cell startup: After 2 to 4 days of continuous microbial inoculation in step (6), the startup of the fuel cell for plant-co-microbial power generation is completed.

2. The plant-co-microorganism power generation method according to claim 1, characterized in that: In step (1), the first conductive carbon material is one of carbon paper, carbon felt, carbon fiber, or graphite; the second conductive carbon material is one of carbon paper, carbon felt, carbon fiber, or graphite. In step (1), the ion exchange membrane is one of a cation exchange membrane, anion exchange membrane, or proton exchange membrane.

3. The plant-co-microorganism power generation method according to claim 2, characterized in that: The first conductive carbon material and the second conductive carbon material are platinum-modified materials, nanoparticle-modified materials, or materials modified with other chemical reagents.

4. The plant-co-microorganism power generation method according to claim 1, characterized in that: In step (1), the temperature during hot pressing is 100-180℃, the pressure during hot pressing is 6-9MPa, and the hot pressing time is 1-20min.

5. The plant-co-microorganism power generation method according to claim 1, characterized in that: In step (2), the exposed plant tissue area includes xylem, phloem, inner bark, roots, and inner plant cells of branches and leaves.

6. The plant-co-microorganism power generation method according to claim 1, characterized in that: In step (4), the outside of the two syringe needles is coated with polyvinyl chloride material.

7. The plant-co-microorganism power generation method according to claim 1, characterized in that: In step (4), the reference electrode is either an Ag / AgX composite reference electrode or a saturated calomel reference electrode.

8. The plant-co-microorganism power generation method according to claim 1, characterized in that: In step (6), the electrochemically active microbial species include the genera *Geobacterium* and *Shewanella*.

9. The plant-co-microorganism power generation method according to claim 1, characterized in that: In step (7), the solution containing an organic carbon source that can be metabolized by electrochemically active microorganisms at a certain concentration contains 0.3–1.5 g L. -1 Physiological saline solution containing 0.3–1.5 g / L glucose -1 Physiological saline containing fructose or containing 0.3–1.5 g / L -1 Lactic acid is one of the components of physiological saline.

10. A plant-assisted microbial power generation device, characterized in that, The plant-synergistic microbial power generation device is used to implement the plant-synergistic microbial power generation method according to any one of claims 1-9, the device comprising: An experimental plant having exposed plant tissue regions covered with a microporous filter membrane; A membrane electrode, wherein the membrane electrode is connected to the exposed plant tissue region covered with a microporous filter membrane, the membrane electrode comprising an anode, an ion exchange membrane, and a cathode; A reference electrode, which is connected between the exposed plant tissue region and the anode via a Luggin capillary tube; A load, which is connected to the anode and cathode via wires; In this method, two syringe needles are inserted between the exposed plant tissue area and the anode to inoculate microorganisms.

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