阅读说明：本技术 一种微生物电解池的泡沫铜材料复合阴极及其制备方法 (Copper foam material composite cathode of microbial electrolytic cell and preparation method thereof ) 是由 李威 何宽畅 吕斯濠 林辉 刘倩 于 2021-09-08 设计创作，主要内容包括：本发明公开了一种微生物电解池的泡沫铜材料复合阴极,包括泡沫铜板和改性粉末硒通过二次灼烧制成。本发明基材价廉易得、高导电性、高比表面积和具有良好的延展性,能实现有效的电荷转移,而且泡沫铜材料复合阴极生物毒性小,而且铜是微生物所需的微量元素,即使溶出也对阳极产电菌影响较小；本发明使用灼烧方法将改性粉末硒熔于泡沫铜板上,步骤简单易行,可实现电极的快速制备,推进该阴极材料规模化应用,烧结时成品成分简单纯粹、无杂质、不需粘合剂；本发明选用粉末硒作为泡沫铜板的负载物,是基于硒优越的导电性质,熔点较低,价格便宜,而且硒是微生物一种必须的微量元素,对生物的相容性较高,不容易造成环境污染。(The invention discloses a copper foam material composite cathode of a microbial electrolytic cell, which comprises a copper foam plate and modified powder selenium, wherein the copper foam plate and the modified powder selenium are prepared by secondary firing. The base material is cheap and easy to obtain, has high conductivity, high specific surface area and good ductility, can realize effective charge transfer, and the copper foam material is low in biological toxicity of the composite cathode, and copper is a trace element required by microorganisms, so that the copper foam material has small influence on anode electrogenesis bacteria even if dissolved out; the invention uses the firing method to melt the modified powder selenium on the foam copper plate, the steps are simple and easy to implement, the rapid preparation of the electrode can be realized, the scale application of the cathode material is promoted, and the finished product has simple and pure components, no impurities and no need of adhesives during sintering; the invention selects the powdered selenium as the load of the copper foam plate, is based on the excellent conductive property of the selenium, has lower melting point and low price, and the selenium is a necessary microelement of microorganism, has higher biocompatibility and is not easy to cause environmental pollution.)

1. The utility model provides a copper foam material composite cathode of microbial electrolysis cell which characterized in that: comprises a copper foam plate and modified powder selenium which are prepared by secondary burning.

2. The copper foam material composite cathode of a microbial electrolysis cell as claimed in claim 1, wherein: the aperture of the copper foam plate is 100-200 mu m, the thickness of the copper foam plate is 1-2mm, and the content of modified powder selenium on the copper foam plate is 0.2-0.4g/cm²。

3. The copper foam material composite cathode of a microbial electrolysis cell as claimed in claim 1, wherein: the aperture of the copper foam plate is 300-400 mu m, the thickness of the copper foam plate is 1-2mm, and the content of modified powder selenium on the copper foam plate is 0.3-0.5g/cm²。

4. The copper foam material composite cathode of a microbial electrolysis cell as claimed in claim 1, wherein: the particle size of the modified powder selenium is 0.5-15um, and the purity of the modified powder selenium is more than 99.9%.

5. A preparation method of a copper foam material composite cathode of a microbial electrolytic cell is characterized by comprising the following steps: the method comprises the following steps:

the method comprises the following steps: preparing modified powder selenium, namely dissolving weighed powder selenium in 75% ethanol solution by using ultrasonic assistance, stirring and mixing uniformly, then sequentially adding a coupling agent and stearic acid, stirring and mixing for 30-60min at 40-60 ℃, then carrying out reduced pressure suction filtration, washing and drying treatment to obtain pretreated powder selenium particles, and carrying out ball milling treatment on the pretreated powder selenium particles under the protection of nitrogen to obtain modified powder selenium for later use;

step two: cleaning the selected foam copper plate, soaking the cleaned foam copper plate in a surface treating agent, reacting for 8-12h at 60-90 ℃, washing with deionized water, and drying to obtain a pretreated foam copper plate for later use;

step three: and (3) uniformly coating the modified powder selenium obtained in the step one on the copper foam plate obtained in the step two, and then carrying out primary ignition, wherein the temperature of the primary ignition is 210-270 ℃, and the ignition time is 2-4 h.

Step four: after the primary burning is finished, the temperature is raised to 590-610 ℃ for secondary burning, the burning time is 20-50min, and after the secondary burning is finished, air cooling is carried out under the protection of nitrogen to obtain the foamed copper material composite cathode of the microbial electrolytic cell.

6. The preparation method of the copper foam material composite cathode of the microbial electrolytic cell according to claim 5, characterized in that: in the first step, the coupling agent and the stearic acid are respectively 2-5% and 10-16% of the weight of the ethanol solution, the pretreated powder selenium particles are subjected to ball milling and then are screened in the first step, and the particle size of the modified powder selenium particles obtained after screening is 0.5-15 um.

7. The preparation method of the copper foam material composite cathode of the microbial electrolytic cell according to claim 5, characterized in that: and in the second step, the foam copper plate is cleaned by sequentially adopting acetone, ethanol, hydrochloric acid aqueous solution and deionized water, and each cleaning solution is cleaned for 2-3 times.

8. The preparation method of the copper foam material composite cathode of the microbial electrolytic cell according to claim 5, characterized in that: the surface treating agent in the second step comprises the following raw materials in parts by weight: 15-20 parts of copper salt, 20-25 parts of silver nitrate solution, 30-40 parts of 1, 4-phthalic acid and 60-80 parts of solvent, wherein the copper salt is Cu (CH)₃COO)₂The solvent is DMF, and the drying temperature in the second step is 60-80 ℃.

9. The preparation method of the copper foam material composite cathode of the microbial electrolytic cell according to claim 5, characterized in that: the burning in the third step is carried out in a muffle furnace.

10. The preparation method of the copper foam material composite cathode of the microbial electrolytic cell according to claim 9, which is characterized in that: the temperature rise rate when the temperature is raised to 590-610 ℃ in the fourth step is 4-6 ℃/min.

Technical Field

The invention relates to the technical field of microbial electrolytic cells, in particular to a copper foam material composite cathode of a microbial electrolytic cell and a preparation method thereof.

Background

With the continuous development of society, people demand more and more energy. The process of obtaining energy also creates a number of environmental pollution problems. Therefore, it is urgent to develop new technologies for generating green renewable energy and reducing environmental pollution caused by the energy use process. Among them, hydrogen is attracting more attention as a clean and efficient energy source, and many methods for producing hydrogen are currently available, and a Microbial Electrolysis Cell (MEC) is one of them. Microbial electrolyzers are a promising approach to energy recovery by microorganisms and can rapidly degrade pollutants. But at the same time, the technology faces the application obstacle at present, and the current technical bottleneck problem mainly lies in how to further reduce the cost of the cathode and improve the hydrogen recovery rate of the cathode and enlarge the reactor, which are the key points of whether the technology can successfully realize industrialization and commercialization in the future.

The microbial electrolytic cell is continuously developed since birth, wherein the single-chamber microbial electrolytic cell is developed from the double-chamber microbial electrolytic cell, the manufacturing cost is lower, the structure is simple, the starting and the operation of the reactor are relatively easy, the structure is more reasonable and practical, and the reactor foundation is laid for promoting the scale and the industrialization of the microbial electrolytic cell. However, the hydrogen recovery rate of the cathode is still a great factor limiting the application of the microbial electrolysis cell, and the hydrogen evolution potential of the cathode material influences the hydrogen recovery condition of the cathode. The carbon cloth is the most widely applied base material, and the metal platinum is a better catalyst applied to the microbial electrolytic cell, but the price is higher, so that in recent years, a plurality of cheap base materials such as carbon paper, carbon felt, stainless steel mesh, foam materials and the like have the tendency of gradually replacing the traditional electrode material carbon cloth, the manufacturing cost of the conventional microbial electrolytic cell is greatly reduced, and the gas production efficiency and the gas production amount have a great space for improvement.

Disclosure of Invention

The invention aims to provide a copper foam material composite cathode of a microbial electrolytic cell and a preparation method thereof, so as to solve the problems in the background technology.

In order to solve the technical problems, the invention provides the following technical scheme: a copper foam material composite cathode of a microbial electrolytic cell comprises a copper foam plate and modified powder selenium, which are prepared by secondary firing.

In a preferred embodiment, the pore diameter of the copper foam plate is 100-200um, the thickness of the copper foam plate is 1-2mm, and the content of the modified powder selenium on the copper foam plate is 0.2-0.4g/cm²。

In a preferred embodiment, the pore diameter of the copper foam plate is 300-400 mu m, the thickness of the copper foam plate is 1-2mm, and the content of modified powder selenium on the copper foam plate is 0.3-0.5g/cm²。

In a preferred embodiment, the particle size of the modified powdered selenium is 0.5-15um, and the purity of the modified powdered selenium is 99.9% or more.

A preparation method of a copper foam material composite cathode of a microbial electrolytic cell comprises the following steps:

the method comprises the following steps: preparing modified powder selenium, namely dissolving weighed powder selenium in 75% ethanol solution by using ultrasonic assistance, stirring and mixing uniformly, then sequentially adding a coupling agent and stearic acid, stirring and mixing for 30-60min at 40-60 ℃, then carrying out reduced pressure suction filtration, washing and drying treatment to obtain pretreated powder selenium particles, and carrying out ball milling treatment on the pretreated powder selenium particles under the protection of nitrogen to obtain modified powder selenium for later use;

step two: cleaning the selected foam copper plate, soaking the cleaned foam copper plate in a surface treating agent, reacting for 8-12h at 60-90 ℃, washing with deionized water, and drying to obtain a pretreated foam copper plate for later use;

step three: and (3) uniformly coating the modified powder selenium obtained in the step one on the copper foam plate obtained in the step two, and then carrying out primary ignition, wherein the temperature of the primary ignition is 210-270 ℃, and the ignition time is 2-4 h.

Step four: after the primary burning is finished, the temperature is raised to 590-610 ℃ for secondary burning, the burning time is 20-50min, and after the secondary burning is finished, air cooling is carried out under the protection of nitrogen to obtain the foamed copper material composite cathode of the microbial electrolytic cell.

In a preferred embodiment, the weight of the coupling agent and the stearic acid in the first step is (2-5%) and (10-16%) of the weight of the ethanol solution, the coupling agent and the stearic acid are washed by deionized water after suction filtration in the first step, the washed coupling agent and the stearic acid are dried at 60-80 ℃, the pretreated selenium powder particles are screened after ball milling in the first step, and the particle size of the modified powder selenium obtained after screening is 0.5-15 um.

In a preferred embodiment, in the second step, the copper foam plate is washed sequentially with acetone, ethanol, a hydrochloric acid aqueous solution and deionized water, and each washing solution is washed for 2-3 times.

In a preferred embodiment, the surface treatment agent in the second step comprises the following raw materials in parts by weight: 15-20 parts of copper salt, 20-25 parts of silver nitrate solution, 30-40 parts of 1, 4-phthalic acid and 60-80 parts of solvent, wherein the copper salt is Cu (CH)₃COO)₂The solvent is DMF, and the drying temperature in the second step is 60-80 ℃.

In a preferred embodiment, the burning in the third step is performed in a muffle furnace.

In a preferred embodiment, the temperature raising rate for raising the temperature to 590-610 ℃ in the fourth step is 4-6 ℃/min.

Compared with the prior art, the invention has the following beneficial effects:

1. the foam copper material composite cathode used in the invention has the advantages that the base material is cheap and easy to obtain, the conductivity is high, the specific surface area is high, the ductility is good, the effective charge transfer can be realized, the biological toxicity of the foam copper material composite cathode is low, copper is a trace element required by microorganisms, and the influence on anode electrogenesis bacteria is small even if the copper is dissolved out; the invention uses the firing method to melt the modified powder selenium on the foam copper plate, the steps are simple and easy to implement, the rapid preparation of the electrode can be realized, the scale application of the cathode material is promoted, and the finished product has simple and pure components, no impurities and no need of adhesives during sintering; the invention selects the powdered selenium as the load of the foam copper plate, is based on the excellent conductive property of the selenium, has lower melting point (the melting point of the selenium is 221 ℃), has low price, is a necessary trace element for microorganisms, has higher biocompatibility and is not easy to cause environmental pollution;

2. according to the invention, the surface treating agent is used for treating the copper foam plate, so that silver particles and metal oxide are loaded on the surface of the copper foam plate, the electric conductivity of the copper foam plate can be better, and the coupling agent and stearic acid are used for modifying the powder selenium, so that the adhesion and the catalytic performance of the powder selenium are better, and the hydrogen evolution effect of the composite cathode material can be effectively improved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:

FIG. 1 is a pictorial representation under SEM of example 1 of the present invention;

FIG. 2 is a pictorial representation under SEM in accordance with example 2 of the present invention;

FIG. 3 is a diagram of an electrode material object of selenium-modified copper foam burned according to example 1 of the present invention;

FIG. 4 is a graph comparing current densities of inventive example 1, inventive example 2 and comparative example.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1:

the invention provides a copper foam material composite cathode of a microbial electrolytic cell, which comprises a copper foam plate and modified powder selenium, wherein the copper foam plate and the modified powder selenium are prepared by secondary firing.

In a preferred embodiment, the pore diameter of the copper foam plate is 100-200um, the thickness of the copper foam plate is 2mm, and the content of the modified powder selenium on the copper foam plate is 0.3g/cm²。

In a preferred embodiment, the particle size of the modified powdered selenium is 0.5-15um, and the purity of the modified powdered selenium is 99.9% or more.

A preparation method of a copper foam material composite cathode of a microbial electrolytic cell comprises the following steps:

the method comprises the following steps: preparing modified powder selenium, namely dissolving weighed powder selenium in 75% ethanol solution by using ultrasonic assistance, stirring and mixing uniformly, then sequentially adding a coupling agent and stearic acid, stirring and mixing for 50min at 50 ℃, then carrying out reduced pressure suction filtration, washing and drying treatment to obtain pretreated powder selenium particles, and carrying out ball milling treatment on the pretreated powder selenium particles under the protection of nitrogen to obtain modified powder selenium for later use;

step two: cleaning the selected foam copper plate, soaking the cleaned foam copper plate in a surface treating agent, reacting for 10 hours at 80 ℃, washing with deionized water, and drying to obtain a pretreated foam copper plate for later use;

step three: and (3) uniformly coating the modified powder selenium in the step one on the copper foam plate obtained in the step two, and then carrying out primary ignition, wherein the temperature of the primary ignition is 250 ℃, and the ignition time is 3 h.

Step four: after the primary burning is finished, the temperature is raised to 600 ℃ for secondary burning, the burning time is 50min, after the secondary burning is finished, air cooling is carried out under the protection of nitrogen to obtain the copper foam material composite cathode of the microbial electrolytic cell, and a physical diagram of the copper foam material composite cathode of the microbial electrolytic cell under SEM is shown in figure 1.

In a preferred embodiment, the weight of the coupling agent and the stearic acid in the first step is 3% and 15% of the weight of the ethanol solution, the coupling agent and the stearic acid are washed by deionized water after suction filtration and dried at 70 ℃, the pretreated powdered selenium particles are screened after ball milling in the first step, and the particle size of the modified powdered selenium obtained after screening is 0.5-15 um.

In a preferred embodiment, in the second step, the copper foam plate is washed by sequentially using acetone, ethanol, a hydrochloric acid aqueous solution and deionized water, and each washing solution is washed for 3 times.

In a preferred embodiment, the surface treatment agent in the second step comprises the following raw materials in parts by weight: 18 parts of copper salt, 22 parts of silver nitrate solution, 35 parts of 1, 4-phthalic acid and 70 parts of solvent, wherein the copper salt is Cu (CH)₃COO)₂The solvent is DMF, and the drying temperature in the second step is 70 ℃.

In a preferred embodiment, the burning in the third step is performed in a muffle furnace.

In a preferred embodiment, the temperature increase rate when the temperature is increased to 600 ℃ in the fourth step is 5 ℃/min.

The foam material composite cathode obtained in the embodiment is applied to a reactor of a microbial electrolytic cell, carbon fibers are selected as microorganism attachment and growth environments, the carbon fibers with the same length are transversely and uniformly distributed on a metal titanium wire, the carbon fibers with the same length are arranged on two sides of the titanium wire serving as the center, then the other titanium wire is overlapped with the first titanium wire, the two titanium wires are used for clamping the carbon fibers, one end of the titanium wire is fixed, the titanium wire is twisted from the other side, the titanium wire forms a spiral carbon fiber bundle in the twisting process, a cylindrical carbon brush anode with the length-diameter ratio of 1:1 is formed, the carbon brush anode is fixed into a cubic reactor with the effective volume of 100mL, and the end of the titanium wire extends out of the reactor and is exposed out of the reactor. Connecting the carbon brush anode, the 10 omega resistor and the foam material composite cathode with a power supply by using a lead to complete the assembly of the microbial electrolytic cell reactor; all the microbial electrolytic cell reactors are acclimatized, started and subsequently operated by using simulated wastewater to simulateThe waste water component is 1g/L^-1Sodium acetate, 20mM phosphate buffer, 0.13g/L^-1Potassium chloride, 0.31g/L^-1Ammonium chloride, 12.5mL/L^-1Microelement solution and 5mL/L^-1A vitamin solution.

Example 2:

the invention provides a copper foam material composite cathode of a microbial electrolytic cell, which comprises a copper foam plate and modified powder selenium, wherein the copper foam plate and the modified powder selenium are prepared by secondary firing.

In a preferred embodiment, the pore diameter of the copper foam plate is 300-400um, the thickness of the copper foam plate is 2mm, and the content of the modified powder selenium on the copper foam plate is 0.4g/cm²。

In a preferred embodiment, the particle size of the modified powdered selenium is 0.5-15um, and the purity of the modified powdered selenium is 99.9% or more.

A preparation method of a copper foam material composite cathode of a microbial electrolytic cell comprises the following steps:

the method comprises the following steps: preparing modified powder selenium, namely dissolving weighed powder selenium in 75% ethanol solution by using ultrasonic assistance, stirring and mixing uniformly, then sequentially adding a coupling agent and stearic acid, stirring and mixing for 50min at 50 ℃, then carrying out reduced pressure suction filtration, washing and drying treatment to obtain pretreated powder selenium particles, and carrying out ball milling treatment on the pretreated powder selenium particles under the protection of nitrogen to obtain modified powder selenium for later use;

step two: cleaning the selected foam copper plate, soaking the cleaned foam copper plate in a surface treating agent, reacting for 10 hours at 80 ℃, washing with deionized water, and drying to obtain a pretreated foam copper plate for later use;

step three: and (3) uniformly coating the modified powder selenium in the step one on the copper foam plate obtained in the step two, and then carrying out primary ignition, wherein the temperature of the primary ignition is 250 ℃, and the ignition time is 3 h.

Step four: after the primary burning is finished, the temperature is raised to 600 ℃ for secondary burning, the burning time is 50min, after the secondary burning is finished, air cooling is carried out under the protection of nitrogen to obtain the copper foam material composite cathode of the microbial electrolytic cell, and a physical diagram of the copper foam material composite cathode of the microbial electrolytic cell under SEM is shown in figure 2.

In a preferred embodiment, the weight of the coupling agent and the stearic acid in the first step is 3% and 15% of the weight of the ethanol solution, the coupling agent and the stearic acid are washed by deionized water after suction filtration and dried at 70 ℃, the pretreated powdered selenium particles are screened after ball milling in the first step, and the particle size of the modified powdered selenium obtained after screening is 0.5-15 um.

In a preferred embodiment, in the second step, the copper foam plate is washed by sequentially using acetone, ethanol, a hydrochloric acid aqueous solution and deionized water, and each washing solution is washed for 3 times.

In a preferred embodiment, the surface treatment agent in the second step comprises the following raw materials in parts by weight: 18 parts of copper salt, 22 parts of silver nitrate solution, 35 parts of 1, 4-phthalic acid and 70 parts of solvent, wherein the copper salt is Cu (CH)₃COO)₂The solvent is DMF, and the drying temperature in the second step is 70 ℃.

In a preferred embodiment, the burning in the third step is performed in a muffle furnace.

In a preferred embodiment, the temperature increase rate when the temperature is increased to 600 ℃ in the fourth step is 5 ℃/min.

Example 3:

the invention provides a copper foam material composite cathode of a microbial electrolytic cell, which comprises a copper foam plate and powdered selenium, wherein the copper foam plate and the powdered selenium are prepared by secondary firing.

In a preferred embodiment, the pore diameter of the copper foam plate is 100-200um, the thickness of the copper foam plate is 2mm, and the content of the modified powder selenium on the copper foam plate is 0.3g/cm²。

In a preferred embodiment, the particle size of the modified powdered selenium is 0.5-15um, and the purity of the modified powdered selenium is 99.9% or more.

A preparation method of a copper foam material composite cathode of a microbial electrolytic cell comprises the following steps:

the method comprises the following steps: cleaning the selected foam copper plate, soaking the cleaned foam copper plate in a surface treating agent, reacting for 10 hours at 80 ℃, washing with deionized water, and drying to obtain a pretreated foam copper plate for later use;

step two: and uniformly coating the powder selenium on the copper foam plate obtained in the step one, and then carrying out primary ignition, wherein the temperature during primary ignition is 250 ℃, and the ignition time is 3 h.

Step three: and after the primary burning is finished, raising the temperature to 600 ℃ for secondary burning, wherein the burning time is 50min, and after the secondary burning is finished, performing air cooling under the protection of nitrogen to obtain the copper foam material composite cathode of the microbial electrolytic cell.

In a preferred embodiment, the copper foam plate is washed in the step one by sequentially using acetone, ethanol, a hydrochloric acid aqueous solution and deionized water, and each washing liquid is washed for 3 times.

In a preferred embodiment, the surface treatment agent in the first step comprises the following raw materials in parts by weight: 18 parts of copper salt, 22 parts of silver nitrate solution, 35 parts of 1, 4-phthalic acid and 70 parts of solvent, wherein the copper salt is Cu (CH)₃COO)₂The solvent is DMF, and the drying temperature in the second step is 70 ℃.

In a preferred embodiment, the burning in the second step is performed in a muffle furnace.

In a preferred embodiment, the temperature rise rate when the temperature is raised to 600 ℃ in step three is 5 ℃/min.

Comparative example:

the preparation method of the traditional cathode taking carbon cloth as a base material is realized according to the following steps:

taking a piece of carbon cloth, mixing carbon powder with polytetrafluoroethylene turbid liquid (PTFE) with the concentration of 30%, shaking, uniformly mixing, smearing on one side of the carbon cloth, drying at room temperature for 15min, heating in a muffle furnace at 380 ℃ for 30min, and cooling at room temperature for 1h to obtain initial carbon cloth;

continuously coating PTFE with the concentration of 60% on the initial cathode, cooling at room temperature for 15min, then carrying out heating treatment in a muffle furnace at 380 ℃ for 30min, cooling at room temperature for 1h, and repeatedly coating, heating and cooling for three times to obtain carbon cloth loaded with a PTFE layer;

and thirdly, mixing 10mg of platinum-carbon catalyst with the platinum mass content of 20%, 50uL of isopropanol, 100uL of Nafion and 12.5uL of deionized water, oscillating and stirring for 40min to form a viscous state to obtain a liquid catalyst, and smearing the liquid catalyst on one side of the carbon cloth without the PTFE layer to obtain the carbon cloth-based foam material composite cathode.

Experimental study on hydrogen production performance was performed using the copper foam material composite cathodes of the microbial electrolytic cells produced in example 1, example 2, and comparative example, and the experimental results are shown in fig. 4.

In FIG. 4, both example 1 and example 2 are higher than the comparative example in view of the current density achievable after start-up of the MEC, and it was calculated that the highest current densities of example 1 and example 2 could achieve 110A/m, respectively^-3And 90A/m^-3While the comparative example has a maximum of less than 60A/m^-3. The current densities of example 1 and example 2 were thus increased by 1.83 times and 1.5 times, respectively, over the comparative current densities.

The hydrogen production was measured at an external resistance of 10 Ω for the copper foam plate composite cathode materials produced in examples 1 to 3 and the cathode material in the comparative example, and the measurement results are shown in table one:

	hydrogen production/L.L-1reactor
		Example 1	0.88
Example 2	0.80
		Example 3	0.72
Comparative example	0.38

Watch 1

As can be seen from table one, the copper foam material composite cathode of the microbial electrolytic cell produced by the method has better hydrogen production compared with the traditional carbon cloth cathode material, and the unmodified powdered selenium is adopted in the example 3, the hydrogen production is better compared with the carbon cloth cathode material, but the hydrogen production is reduced compared with the example 1; the invention uses the firing method to melt the modified powder selenium on the foam copper plate, the steps are simple and easy to implement, the rapid preparation of the electrode can be realized, the scale application of the cathode material is promoted, and the finished product has simple and pure components, no impurities and no need of adhesives during sintering; the invention selects the powdered selenium as the load of the foam copper plate, is based on the excellent conductive property of the selenium, has lower melting point (the melting point of the selenium is 221 ℃), has low price, is a necessary trace element for microorganisms, has higher biocompatibility and is not easy to cause environmental pollution; according to the invention, the surface treating agent is used for treating the copper foam plate, so that silver particles and metal oxide are loaded on the surface of the copper foam plate, the electric conductivity of the copper foam plate can be better, and the coupling agent and stearic acid are used for modifying the powder selenium, so that the adhesion and the catalytic performance of the powder selenium are better, and the hydrogen evolution effect of the composite cathode material can be effectively improved.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.