Application of FeS2 / MoS2 heterostructure as anode material of microbial fuel cell in treatment of wastewater

Abstract

The application discloses a kind of heterostructures, including the following method preparation is obtained: anhydrous ferric chloride, sodium dodecyl sulfate and first portion of thiourea are added to deionized water, under stirring condition, 5~7 h after, second portion of thiourea is added, continue stirring 1~3 h, then heating 24~36 h under 180~220 DEG C, collect precipitate, after washing, dry 12~24 h under 70~90 DEG C, obtain heterostructure.The heterostructure is used as microbial fuel cell anode material, load heterostructure to carbon cloth to obtain microbial fuel cell anode, microbial fuel cell anode is used to process medium and high concentration organic wastewater, can improve the power generation performance of microbial fuel cell and COD removal rate of medium and high concentration organic wastewater.

Description

Technical Field

[0001] This invention belongs to the field of microbial fuel cell technology, specifically relating to a... Application of heterogeneous structures as anode materials for microbial fuel cells in wastewater treatment. Background Technology

[0002] With rapid social development and continuous resource utilization, environmental issues have gradually become a major global concern, and wastewater treatment has become a crucial part of these issues. The paper industry is a major water consumer and also one of the largest producers of wastewater. Pulping wastewater accounts for a relatively large proportion of my country's total industrial wastewater. Paper industry wastewater can be divided into sulfate pulp wastewater and sulfite pulp wastewater. This wastewater contains large amounts of organic matter and suspended solids, as well as numerous chemicals and impurities, making it one of the major sources of water pollution in my country.

[0003] Microbial fuel cells (MFCs), as an environmentally friendly new technology that simultaneously treats wastewater and generates electricity, offer advantages over other wastewater treatment technologies. These advantages include mild operating conditions, typically functioning at ambient temperature and pressure in a near-neutral environment, resulting in high battery safety and low maintenance costs. Furthermore, they require no energy input and convert the chemical energy of organic matter in wastewater into electrical energy, achieving zero emissions and no pollution. However, their low power generation performance and low wastewater treatment efficiency hinder the widespread practical application of MFCs. The anode, as the core of MFC operation, determines the electrocatalytic activity of the electroactive biofilm and also affects the wastewater treatment effect. Therefore, preparing anode materials with good biocompatibility, high power generation performance, and high wastewater treatment efficiency can expand the application scope of MFCs in wastewater treatment, environmental bioremediation, and other fields while generating electricity.

[0004] Traditional carbon-based anode materials, including carbon cloth (CC), carbon brushes, and carbon felt, are often used as anode materials due to their high stability and conductivity. However, they have smooth surfaces, low specific surface areas, weak bacterial adhesion, and poor electrocatalytic performance for redox reactions in the medium, usually exhibiting low power output. Summary of the Invention

[0005] The technical problem to be solved by this invention is to overcome the shortcomings of existing microbial fuel cells, such as low power generation performance and low wastewater treatment efficiency, and to provide a... Heterogeneous structure, Heterogeneous structures, when used as anode materials for microbial fuel cells, can improve the power generation performance of microbial fuel cells and the COD removal rate of medium-to-high concentration organic wastewater.

[0006] The technical problem to be solved by this invention is achieved through the following solution:

[0007] A sort of The heterostructure was prepared by the following method: anhydrous ferric chloride, sodium dodecyl sulfate, and a first portion of thiourea were added to deionized water, and under stirring conditions, [further steps were taken]. After 5-7 hours, add the second part of thiourea, continue stirring for 1-3 hours, then heat at 180-220℃ for 24-36 hours. Collect the precipitate, wash it, and dry it at 70-90℃ for 12-24 hours to obtain... Heterogeneous structure.

[0008] Based on the addition of anhydrous ferric chloride of 0.50~1.50 g, the corresponding addition of sodium dodecyl sulfate is calculated to be 0.45 g~1.35 g, and the addition of the first portion of thiourea is 0.25 g~0.70 g.

[0009] by In heterostructures The molar percentage is calculated as 4%~12%. The amount added; The molar ratio of the second thiourea to the first is 1:5.

[0010] One of the present inventions Heterogeneous structures as anode materials for microbial fuel cells will Heterogeneous structures are loaded onto pretreated carbon cloth to obtain microbial fuel cell anodes. Microbial fuel cell anodes are used to treat medium-to-high concentration organic wastewater (concentration range of 3000~12000 mg / L), which can improve the power generation performance of microbial fuel cells and the COD removal rate of medium-to-high concentration organic wastewater.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] (1) The present invention Heterogeneous structures have interface defects, which increase the number of edge active sites and improve catalytic performance; strong electron interactions at the interface accelerate electron transport, which is beneficial to the transfer of extracellular electrons in the anode, thereby improving the anode's power generation performance and wastewater treatment capacity.

[0013] (2) In this invention The heterogeneous structure has a nano-flower cluster shape, a large specific surface area, and high biocompatibility, which is conducive to bacterial adhesion and can improve the power generation performance of microbial fuel cells and the COD removal rate of medium and high concentration organic wastewater. Attached Figure Description

[0014] Figure 1 for and , , Scanning electron microscope (SEM) images;

[0015] Figure 2 for SEM images and X-ray energy dispersive spectroscopy (EDS) images of C, Fe, Mo, S and N elements;

[0016] Figure 3 yes , , , Cyclic voltammetry (CV) curves;

[0017] Figure 4 yes , , , Electrochemical impedance spectroscopy (EIS) curves;

[0018] Figure 5 yes , , , Anode Output voltage curve;

[0019] Figure 6 yes Anode at Image showing COD removal rate after stable operation. Detailed Implementation

[0020] Example 1

[0021] One of the present inventions The preparation method of the heterostructure is as follows: 1.14 g of anhydrous ferric chloride, 1.00 g of sodium dodecyl sulfate, and 0.53 g of thiourea were added to 70 mL of deionized water to prepare three parallel samples. Under stirring conditions, the mixture was... In heterostructures The corresponding molar percentages are calculated as 4%, 8%, and 12%. The amount added was divided into three parallel samples. After 6 hours, thiourea (of which...) was added... The mixture was stirred for 2 h at a molar ratio of 1:5 with thiourea, then transferred to a 100 mL Teflon-lined autoclave and heated at 200 °C for 25 h. The precipitate was collected and washed with ultrapure water and anhydrous ethanol. It was then dried in a vacuum oven at 80 °C for 18 h to obtain the products containing... The molar percentages were 4%, 8%, and 12%, respectively. Heterogeneous structures, respectively labeled as , , .

[0022] Pretreatment method for carbon fiber cloth: Cut the carbon fiber cloth into... The carbon cloth was ultrasonically cleaned for 20 minutes each with acetone, anhydrous ethanol, and deionized water to remove surface grease, and then subjected to further cleaning in a tube furnace at 350°C. Heating under ambient conditions for 3 hours.

[0023] Weigh out 9.2 mg of each. , , The solutions were placed in separate centrifuge tubes, and 49.6 μL of deionized water, 100 μL of isopropanol, and 57.12 μL of 5 wt% Nafion solution were added to each tube. The tubes were sonicated for 30 min to ensure uniform dispersion. The mixture was then evenly coated onto both sides of the pretreated carbon cloth and dried at room temperature. A blank carbon cloth was used as a control. Titanium wires were attached to the carbon cloth using conductive silver paste to obtain blank carbon cloth (CC) and carbon cloth containing... The molar percentages were 4%, 8%, and 12%, respectively. The carbon cloth microbial fuel cell anodes are labeled as follows: electrode, electrode, Electrodes and electrode.

[0024] Example 2

[0025] One of the present inventions The preparation method of the heterostructure is as follows: 0.50 g of anhydrous ferric chloride, 0.45 g of sodium dodecyl sulfate, and 0.25 g of thiourea were added to 40 mL of deionized water to prepare three parallel samples. Under stirring conditions, the mixture was... In heterostructures The corresponding molar percentages are calculated as 4%, 8%, and 12%. The amount added was divided into three parallel samples. After 5 hours, thiourea (of which...) was added... The mixture was stirred for 1 h (molar ratio of thiourea to thiourea was 1:5), then transferred to a 100 mL Teflon-lined autoclave and heated at 180 °C for 24 h. The precipitate was collected and washed with ultrapure water and anhydrous ethanol. It was then dried in a vacuum oven at 70 °C for 12 h to obtain the products containing... The molar percentages were 4%, 8%, and 12%, respectively. Heterogeneous structures, respectively labeled as , , .

[0026] Pretreatment method for carbon fiber cloth: Cut the carbon fiber cloth into... The carbon cloth was ultrasonically cleaned for 20 minutes each with acetone, anhydrous ethanol, and deionized water to remove surface grease, and then subjected to further cleaning in a tube furnace at 350°C. Heating under ambient conditions for 3 hours.

[0027] Weigh out 9.2 mg of each. , , The solutions were placed in separate centrifuge tubes, and 49.6 μL of deionized water, 100 μL of isopropanol, and 57.12 μL of 5 wt% Nafion solution were added to each tube. The mixtures were sonicated for 30 min to ensure uniform dispersion. The mixture was then evenly coated onto both sides of the pretreated carbon cloth and dried at room temperature. A blank carbon cloth was used as a control. Titanium wires were attached to the carbon cloth using conductive silver paste to obtain blank carbon cloth (CC) and carbon cloth containing... The molar percentages were 4%, 8%, and 12%, respectively. The carbon cloth microbial fuel cell anodes are labeled as CC electrodes, respectively. electrode, Electrodes and electrode.

[0028] Example 3

[0029] One of the present inventions The preparation method of the heterostructure is as follows: 1.50 g of anhydrous ferric chloride, 1.35 g of sodium dodecyl sulfate, and 0.70 g of thiourea were added to 90 mL of deionized water to prepare three parallel samples. Under stirring conditions, the mixture was... In heterostructures The corresponding molar percentages are calculated as 4%, 8%, and 12%. The amount added was divided into three parallel samples. After 7 hours, thiourea (of which...) was added... The mixture was stirred for 3 h (molar ratio of thiourea to thiourea was 1:5), then transferred to a 100 mL Teflon-lined autoclave and heated at 220 °C for 36 h. The precipitate was collected and washed with ultrapure water and anhydrous ethanol. It was then dried in a vacuum oven at 90 °C for 24 h to obtain the products containing... The molar percentages were 4%, 8%, and 12%, respectively. Heterogeneous structures, respectively labeled as , , .

[0030] Pretreatment method for carbon fiber cloth: Cut the carbon fiber cloth into... The carbon cloth was ultrasonically cleaned for 20 minutes each with acetone, anhydrous ethanol, and deionized water to remove surface grease, and then subjected to further cleaning in a tube furnace at 350°C. Heating under ambient conditions for 3 hours.

[0031] Weigh out 9.2 mg of each. , , The solutions were placed in separate centrifuge tubes, and 49.6 μL of deionized water, 100 μL of isopropanol, and 57.12 μL of 5 wt% Nafion solution were added to each tube. The tubes were sonicated for 30 min to ensure uniform dispersion. The mixture was then evenly coated onto both sides of the pretreated carbon cloth and dried at room temperature. A blank carbon cloth was used as a control; titanium wires were attached to the carbon cloth using conductive silver paste to obtain blank carbon cloth (CC) and carbon cloth containing... The molar percentages were 4%, 8%, and 12%, respectively. The carbon cloth microbial fuel cell anodes are labeled as CC electrodes, respectively. electrode, Electrodes and electrode.

[0032] Construction and Start-up of a Single-Chamber Microbial Fuel Cell: The reactor used in this example is a 100 mL bottle-type single-chamber membrane-free air cathode microbial fuel cell (SC-MFC). It requires high-temperature sterilization before use to ensure no residual microorganisms remain inside. The anode chamber of the microbial fuel cell is inoculated with 10 mL of acclimated anaerobic granular sludge using a sterile syringe, followed by 10 mL of bacterial solution previously enriched in the SC-MFC, and 80 mL of prepared nutrient solution. Pretreated carbon cloth is used as the cathode material. Four different electrodes were prepared... , , , Four microbial fuel cells were obtained, each serving as the anode of a microbial fuel cell. Under a constant temperature of 30°C, the microbial fuel cells were operated with an external 1000 Ω resistor. Data was collected every 10 minutes using a multi-channel fuel cell voltage tester. When the battery output voltage dropped to 50 mV, 80 mL of inoculum was replaced in the anode chamber, while 20 mL of bacterial culture was retained to ensure rapid battery startup after the addition of fresh nutrient solution. This cycle was repeated until the output voltage stabilized and reached over 100 mV, at which point startup was considered successful.

[0033] The following uses the material prepared in Example 1 as a representative to illustrate the performance of the material prepared in this invention. Examples 2 and 3 also achieved the same technical effect.

[0034] Figure 1 for and , , Scanning electron microscope (SEM) images of the prepared The flower cluster structure and granules are loosely combined. Furthermore, the near-spherical shape reduces the specific surface area. Its three-dimensional flower-like structure is tightly bound and greatly increases the specific surface area of ​​the anode, which is conducive to the attachment of electrogenic bacteria and the formation of biofilm.

[0035] Figure 2 for The SEM images and X-ray energy dispersive spectroscopy (EDS) images of C, Fe, Mo, S, and N elements show that Fe, Mo, and S are uniformly distributed throughout the region and overlap with each other, confirming that... Successful preparation of heterostructures.

[0036] Figure 3 yes , , , Cyclic voltammetry (CV) curves, The modified electrode exhibits a higher capacitive current than the CC anode, which means there are more electrocatalytic active sites, thereby improving the power generation performance of MFCs. electrode, Electrodes and The area under the curve for the electrode is also higher than that for CC, further proving... Modification facilitates the adhesion of electroactive bacteria and provides more active sites for electrocatalytic redox reactions.

[0037] Figure 4 yes , , , The electrochemical impedance spectroscopy (EIS) curves, compared with other control groups, The electrode had the lowest Rct (81.12Ω), indicating that an appropriate amount of... Doping is more conducive to improving heterostructure and spatial structure, and enhancing catalytic activity. Doping The resulting composite catalyst exhibits the lowest charge transfer resistance and the fastest charge transfer, consistent with the output voltage results.

[0038] Figure 5 yes , , , When used as an anode, the output voltage curve of MFCs shows that in the early stage (0-5 days) when the influent COD is low, The MFCs output voltage corresponding to the electrode reaches a maximum of 656 mV, and the maximum power density reaches [value missing]. The maximum current density reached When the COD concentration later increased to 12000 mg / L, The maximum output voltage of the MFCs corresponding to the electrode can still reach 456 mV and remain stable, at which point the power density and current density are respectively and This indicates that the prepared It can improve the power generation performance of microbial fuel cells.

[0039] Figure 6 yes Image showing COD removal rate of the anode after stable operation of MFCs, under the condition of influent COD of 3000 mg / L. The COD removal rate can reach 97.41%. When the influent COD is increased to 12000 mg / L, the COD removal rate of MFCs can still reach 83.41%, which is higher than most microbial fuel cells that treat wastewater of the same intensity. This indicates that the prepared anode material can improve the COD removal rate of medium and high concentration organic wastewater.

[0040] Therefore, the present invention Heterogeneous structures used as anode materials for microbial fuel cells have a higher specific surface area, better biocompatibility, and more catalytic active sites, resulting in higher power density and higher COD removal rate when treating wastewater, making them suitable as anode materials for microbial fuel cells.

Claims

1. A kind The application of heterogeneous structures as anode materials for microbial fuel cells in wastewater treatment, The heterostructure was prepared by the following method: anhydrous ferric chloride, sodium dodecyl sulfate, and a first portion of thiourea were added to deionized water, and under stirring conditions, [further steps were taken]. After 5-7 hours, add the second part of thiourea, continue stirring for 1-3 hours, then heat at 180-220℃ for 24-36 hours. Collect the precipitate, wash it, and dry it at 70-90℃ for 12-24 hours to obtain... Heterogeneous structure.

2. The application according to claim 1, characterized in that: Based on the addition of anhydrous ferric chloride of 0.50~1.50 g, the corresponding addition of sodium dodecyl sulfate is calculated to be 0.45~1.35 g, and the addition of the first portion of thiourea is 0.25~0.70 g.

3. The application according to claim 1, characterized in that: by In heterostructures The molar percentage is calculated as 4%~12%. The amount added; The molar ratio of the second thiourea to the first is 1:

5.

4. The application according to claim 1, characterized in that: The Heterogeneous structures are loaded onto carbon cloth to obtain microbial fuel cell anodes.

5. The application according to claim 1, characterized in that: The wastewater is a medium-to-high concentration organic wastewater with a concentration range of 3000~12000 mg / L.

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