阅读说明：本技术 一种超亲气电极提高微生物燃料电池产电量的工艺 (Process for improving electricity production of microbial fuel cell by using super-hydrophilic electrode ) 是由 喻长远 邱松 杨昭 国震宇 许立达 孙晓明 孙浩然 陈天童 于 2020-07-06 设计创作，主要内容包括：一种超亲气电极提高微生物燃料电池产电量的工艺涉及利用电极提高微生物燃料电池(MFC)产电量的技术,特指一种利用“Co(OH)_2+N-CNTs+PTFE+碳布(CFC)”的修饰方法得到超亲气性质的CFC,并将CFC作为MFC的阴极,提高阴极气液固三相的反应速度,加快氧气的ORP反应,最终实现MFC产电量提高,该工艺对MFC电池的改动较小,且可以大幅提高MFC的产电量,为MFC的大规模应用提供一定的借鉴。(A process for improving the electricity generation of a microbial fuel cell by an ultra-hydrophilic electrode relates to a technology for improving the electricity generation of a Microbial Fuel Cell (MFC) by using an electrode, in particular to a process for improving the electricity generation of a microbial fuel cell by using' Co (OH) 2 The modification method of + N-CNTs + PTFE + carbon cloth (CFC) obtains CFC with super-hydrophilic property, and the CFC is used as the cathode of the MFC, so that the reaction speed of gas-liquid-solid three phases of the cathode is improved, the ORP reaction of oxygen is accelerated, and the improvement of the electricity generation quantity of the MFC is finally realized.)

1. A process for improving the electricity production of a microbial fuel cell by using a super-hydrophilic electrode is characterized by comprising the following steps:

step 1: pretreating CFC, namely performing surface activation pretreatment on the CFC by using an oxygen plasma cleaning machine, wherein the treatment time is 20-30min, the radio frequency is 40KHz, and the radio frequency power is high;

step 2: growth of Co (OH)₂Adding the pretreated CFC into a reaction kettle, wherein the mass volume ratio of the CFC to the deionized water solution is 0.0075g/mL, and the deionized water solution specifically contains Co (NO) with the final concentration of 5mM₃)₂·6H₂O, 10mM CO (NO)₂)₂And 5-10mM NH₄F, fully reacting with deionized water solution; the reaction temperature is 120 ℃, and the reaction time is 12 hours;

and step 3: taking the CFC reacted in the step 2 out of the reaction kettle, cleaning and airing, transferring the CFC into a polymerization reactor, adding 1-2g of melamine into each gram of CFC, and heating the CFC in an argon environment to complete the growth of the N-CNTs; the reaction temperature is 600 ℃, and the reaction time is 30 min;

and 4, step 4: modifying PTFE, namely soaking CFC for growing N-CNTs in 0.5-1.5 wt% of PTFE aqueous dispersion solution, taking out, and heating under the condition of argon to complete modification; the heating temperature is 350 deg.C, and the heating time is 40 min.

2. The method of claim 1, wherein the soaking time in step 4 is 5 min.

Technical Field

The invention relates to the technical field of improving the electricity production of Microbial Fuel Cells (MFCs) by utilizing electrodes.

Background

With the continuous development of economic and social productivity, the demand on energy is stronger, traditional energy sources such as coal, oil, natural gas and the like occupy most of the modern energy consumption, but the traditional energy sources are non-renewable, and with continuous exploitation, the reserves can be continuously reduced and the exploitation difficulty can be higher and higher. Therefore, new renewable energy sources, such as solar energy, wind energy, geothermal energy, etc., have gained wide attention in all communities. MFC has received a lot of attention from scientists in the search for new energy.

The MFC is a novel technology for generating electricity by using microorganisms, and is divided into an anode chamber and a cathode chamber by using a proton membrane in a manual control mode, so that an electron generation process and an electron transfer reduction process of the microorganisms are separated, the cathode and the anode are connected through an external lead, and a load is added on the lead, so that electric energy generated in a microorganism metabolism process is obtained.

Although MFC has been noticed and studied by scientists, its relatively low power generation limits its further applications, and thus how to increase the power generation of MFC becomes a hot spot in the academic world. The MFC assembly mode, cathode materials, anode materials, microorganism species and the like all have significant influence on the electricity generation effect of the MFC.

The patent "a method based on carbon nanotube polydopamine composite material microbial fuel cell" [ CN110862538A ] discloses a method based on carbon nanotube polydopamine composite material microbial fuel cell, the ultrasonic dispersion is carried out by adding hydroxylated multi-arm carbon nanotubes into a solvent, and the mixture of CNTs-COOH and dopamine hydrochloride after the ultrasonic dispersion is connected into the anode chamber of the built MFC to be used as the anolyte of the cell.

The patent CN106159281B discloses a high-performance microbial fuel cell based on a molybdenum nitride cathode, wherein the cathode is prepared by coating a Nafion solution with the mixed concentration of 5 wt% of molybdenum nitride on carbon paper. The invention can improve the electrochemical performance of the microbial fuel cell, but the electrochemical performance of the microbial fuel cell needs to be improved by firstly preparing the molybdenum nitride particles from the paper cup, then preparing the Nafion solution of the molybdenum nitride, and finally adsorbing the Nafion solution onto the cathode of the carbon paper, so that the operation steps are longer, and the adsorbed molybdenum nitride particles have the risk of falling off in the using process.

The invention provides a novel air cathode diffusion layer of a cellulose-based single-chamber microbial fuel cell, which takes natural cellulose as a raw material and is compounded with a Pt/C and nafion layer on the diffusion layer to prepare the air cathode.

The invention takes CFC as a research object, and forms a loose and porous fluffy structure on the surface of the CFC through the modification process of 'Co (OH)2+ N-CNTs + PTFE + carbon cloth (CFC)', thereby improving the surface hydrophilicity of the CFC and accelerating the OPR reaction on the surface of the CFC, further improving the power generation quantity of the MFC, and having certain technical help for the practical popularization and application of the MFC.

Disclosure of Invention

Aiming at the condition of low power generation efficiency of the MFC, the invention aims to provide a CFC cathode material with super-hydrophilicity, and the super-hydrophilicity of the CFC is utilized to improve ORP reaction of a cathode, so that the power generation capacity of the MFC is improved. The technology has the characteristics of simple modification technology, high material modification efficiency, small modification on MFC, easy realization of industrialization and the like.

In order to achieve the above object, the invention adopts the technical scheme that:

step 1: pretreating CFC, namely performing surface activation pretreatment on the CFC by using an oxygen plasma cleaning machine, wherein the treatment time is 20-30min, the radio frequency is 40KHz, and the radio frequency power is high;

step 2: growth of Co (OH)₂The nano coating, the pretreated CFC is added into a reaction kettle, and the addition amount is in the mass volume ratio of the deionized water solution0.0075g/mL, and the deionized water solution contains Co (NO) with final concentration of 5mM₃)₂·6H₂O, 10mM CO (NO)₂)₂And 5-10mM NH₄F, fully reacting with deionized water solution; the reaction temperature is 120 ℃, and the reaction time is 12 hours;

and step 3: taking the CFC reacted in the step 2 out of the reaction kettle, cleaning and airing, transferring the CFC into a polymerization reactor, adding 1-2g of melamine into each gram of CFC, and heating the CFC in an argon environment to complete the growth of the N-CNTs; the reaction temperature is 600 ℃, and the reaction time is 30 min;

and 4, step 4: modifying PTFE, namely soaking CFC for growing N-CNTs in 0.5-1.5 wt% of PTFE aqueous dispersion solution, taking out, and heating under the condition of argon to complete modification; the heating temperature is 350 deg.C, and the heating time is 40 min.

On the basis of the technical scheme, the CFC quality mentioned in all the steps is the CFC quality weighed in the step 1;

on the basis of the technical scheme, the reaction temperature in the step 2 is 120 ℃, and the reaction time is 12 hours;

on the basis of the technical scheme, the reaction temperature in the step 3 is 600 ℃, and the reaction time is 30 min;

on the basis of the technical scheme, the soaking time in the step 4 is 5min, the heating temperature is 350 ℃, and the heating time is 40 min.

The CFC treated by the method has good gas-loving performance, the water contact angle is obviously improved, and the electricity generation quantity of the MFC is obviously improved when the CFC is applied to the MFC.

The innovation point and the practical significance of the process are as follows:

1) by carrying out super-hydrophilic modification on the CFC cathode material, a porous and rough fluffy structure is constructed on the surface of the CFC, which is beneficial to the adsorption of oxygen and the improvement of the reaction speed of the three-phase reaction;

2) the modified CFC is applied to the MFC, can effectively improve the electricity generation quantity of the MFC, and provides technical support for further popularization and application of the MFC.

Drawings

FIG. 1 is a schematic representation of CFC modification.

FIG. 2 is a schematic diagram of the structure of an MFC.

Detailed Description

The invention mainly realizes the improvement of the MFC electricity production quantity by the following method:

step 1: taking the modified CFC (3 x 3cm) as a cathode material of the MFC;

step 2: 150mL of anolyte is injected into the anode chamber, 0.15g of sodium acetate is added as a carbon source, and 0.3g of E.coli-K12 is added as an inoculation strain;

and step 3: the MFC is externally connected with a 1000 omega resistor serving as a load, and voltage data are collected through a data collector and transmitted to a computer for storage;

and 4, step 4: the cathode chamber is aerated by an aeration head to provide oxygen.

On the basis of the technical scheme, the aeration rate of the cathode aeration head is 0.2L/min;

on the basis of the technical scheme, the acquisition frequency of the voltage data acquisition unit is 1 Hz.

The modified CFC has obviously improved air affinity, can better adsorb oxygen bubbles, effectively accelerates the three-phase reaction on the CFC, and improves the electricity generation effect of the MFC.

The method has the advantages that a porous and rough fluffy structure is constructed on the surface of the CFC through the modification of the CFC, the gas affinity performance of the CFC is obviously improved, the modified CFC has the advantages of small structural modification of the MFC, obvious improvement of the power generation effect of the MFC and the like when being applied to the MFC, has certain technical reference significance for the popularization and application of the MFC, and has certain social and economic benefits.

The examples are as follows:

example 1:

step 1: pretreating CFC for 20min by an oxygen plasma cleaning machine, wherein the radio frequency is 40KHz, and the radio frequency power is 200W;

step 2: cutting pretreated CFC into 3 × 3cm, adding 0.3g (required amount of 40mL of 0.0075 g/mL), and adding Co (NO) to the reactor to obtain final product₃)₂·6H₂O(5mM)、CO(NO₂)₂(10mM) and NH₄40mL of F (5mM) deionized water solution, and fully reacting at 120 ℃ for 12 hours;

and step 3: taking out CFC in the kettle, cleaning and airing, transferring to a polymerization reactor, adding 1g of melamine into each gram of CFC, and heating to 600 ℃ for reaction for 30min under the condition of argon;

and 4, step 4: taking out CFC, cooling, soaking in 0.5 wt% PTFE water dispersion solution for 5min, taking out, placing in argon gas condition, heating to 350 deg.C, and reacting for 30 min;

and 5: modified CFC material (3 x 3cm) as cathode of MFC;

step 6: 150mL of anolyte is injected into the anode chamber, and 0.15g of sodium acetate and 0.3g of E.coli-K12 are added as a carbon source and inoculated with bacteria;

and 7: the cathode chamber is aerated by air, and the aeration rate is 0.2L/min;

and 8: the MFC is externally connected with a 1000 omega resistor, a load signal of the resistor is acquired by a data acquisition unit, and the acquisition frequency is 1 Hz.

The contact angle of the modified CFC and water is 148.5, the voltage of the MFC after stabilization is 30mV, and the generated energy intensity is 0.036 mW.h.

Example 2:

step 1: pretreating CFC for 30min by an oxygen plasma cleaning machine, wherein the radio frequency is 40KHz, and the radio frequency power is 200W;

step 2: cutting pretreated CFC into 3 × 3cm, adding 0.3g (required amount corresponding to 0.0075g/mL concentration of 40mL deionized water solution) into the reaction kettle, and adding Co (NO) into the kettle₃)₂·6H₂O(8mM)、CO(NO₂)₂(15mM) and NH₄40mL of F (10mM) deionized water solution, and fully reacting at 120 ℃ for 12 hours;

and step 3: taking out CFC in the kettle, cleaning and airing, transferring to a polymerization reactor, adding 2g of melamine into each gram of CFC, and heating to 600 ℃ for reaction for 30min under the condition of argon;

and 4, step 4: taking out CFC, cooling, soaking in 1.5 wt% PTFE water dispersion solution for 5min, taking out, placing in argon gas condition, heating to 350 deg.C, and reacting for 30 min;

and 5: modified CFC material (3 x 3cm) as cathode of MFC;

step 6: 150mL of anolyte is injected into the anode chamber, and 0.15g of sodium acetate and 0.3g of E.coli-K12 are added as a carbon source and inoculated with bacteria;

and 7: the cathode chamber is aerated by air, and the aeration rate is 0.2L/min;

and 8: the MFC is externally connected with a 1000 omega resistor, a load signal of the resistor is acquired by a data acquisition unit, and the acquisition frequency is 1 Hz.

Through determination, the contact angle of the modified CFC and water is 161.5, the voltage of the MFC after stabilization is 40mV, and the generated energy intensity is 0.064 mW.h.

Example 3:

step 1: pretreating CFC with oxygen plasma cleaner for 25min, wherein the radio frequency is 40KHz, and the radio frequency power is 200W;

step 2: cutting pretreated CFC into 3 × 3cm, adding 0.3g (required amount corresponding to 0.0075g/mL concentration of 40mL deionized water solution) into the reaction kettle, and adding Co (NO) to final concentration₃)₂·6H₂O(7mM)、CO(NO₂)₂(12mM) and NH₄40mL of F (8mM) deionized water solution, and fully reacting at 120 ℃ for 12 hours;

and step 3: taking out CFC in the kettle, cleaning and airing, transferring to a polymerization reactor, adding 1.8g of melamine into each gram of CFC, and heating to 600 ℃ under the argon condition for reaction for 30 min;

and 4, step 4: taking out CFC, cooling, soaking in 1.2 wt% PTFE water dispersion solution for 5min, taking out, placing in argon gas condition, heating to 350 deg.C, and reacting for 30 min;

and 5: modified CFC material (3 x 3cm) as cathode of MFC;

step 6: 150mL of anolyte is injected into the anode chamber, and 0.15g of sodium acetate and 0.3g of E.coli-K12 are added as a carbon source and inoculated with bacteria;

and 7: the cathode chamber is aerated by air, and the aeration rate is 0.2L/min;

and 8: the MFC is externally connected with a 1000 omega resistor, a load signal of the resistor is acquired by a data acquisition unit, and the acquisition frequency is 1 Hz.

Through measurement, the contact angle of the modified CFC and water is 154.5, the voltage of the MFC after stabilization is 36mV, and the generated energy intensity is 0.052 mW.h.

Example 4:

step 1: pretreating CFC for 20min by an oxygen plasma cleaning machine, wherein the radio frequency is 40KHz, and the radio frequency power is 200W;

step 2: cutting pretreated CFC into 3 × 3cm, adding 0.3g (required amount of 40mL of 0.0075 g/mL), adding Co (NO) into the reaction kettle₃)₂·6H₂O(6mM)、CO(NO₂)₂(14mM) and NH₄40mL of F (6mM) deionized water solution, and fully reacting at 120 ℃ for 12 hours;

and step 3: taking out CFC in the kettle, cleaning and airing, transferring to a polymerization reactor, adding 1.3g of melamine into each gram of CFC, and heating to 600 ℃ under the argon condition for reaction for 30 min;

and 4, step 4: taking out CFC, cooling, soaking in 0.8 wt% PTFE water dispersion solution for 5min, taking out, placing in argon gas condition, heating to 350 deg.C, and reacting for 30 min;

and 5: modified CFC material (3 x 3cm) as cathode of MFC;

step 6: 150mL of anolyte is injected into the anode chamber, and 0.15g of sodium acetate and 0.3g of E.coli-K12 are added as a carbon source and inoculated with bacteria;

and 7: the cathode chamber is aerated by air, and the aeration rate is 0.2L/min;

and 8: the MFC is externally connected with a 1000 omega resistor, a load signal of the resistor is acquired by a data acquisition unit, and the acquisition frequency is 1 Hz.

The contact angle of the modified CFC and water is 151.5, the voltage of the MFC after stabilization is 33mV, and the generated energy intensity is 0.044 mW.h.

The comparative examples are as follows:

comparative example:

step 1: the unmodified CFC was cut to 3 × 3cm size as the cathode of the MFC;

step 2: 150mL of anolyte is injected into the anode chamber, and 0.15g of sodium acetate and 0.3g of E.coli-K12 are added as a carbon source and inoculated with bacteria;

and step 3: the cathode chamber is aerated by air, and the aeration rate is 0.2L/min;

and 4, step 4: the MFC is externally connected with a 1000 omega resistor, a load signal of the resistor is acquired by a data acquisition unit, and the acquisition frequency is 1 Hz.

The contact angle of unmodified CFC with water was determined to be 136.9, the voltage after stabilization of MFC was 21mV, and the energy intensity generated was 0.018 mW.h.