Preparation method and application of electro-fenton composite electrode containing silicone oil
By etching graphite felt and adding silicone oil, combined with ion exchange membranes, the oxygen diffusion and active oxygen formation capabilities of electro-Fenton technology are enhanced, solving the problems of insufficient active sites in carbon materials and liquid electrolyte contamination, and achieving efficient degradation and low-cost treatment of organic pollutants.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- UNIV OF JINAN
- Filing Date
- 2024-12-09
- Publication Date
- 2026-06-26
AI Technical Summary
The lack of active sites in carbon materials in existing electro-Fenton technology leads to low hydrogen peroxide yield, liquid electrolytes cause secondary pollution, and oxygen transport is difficult under flooded conditions, affecting the degradation efficiency of organic pollutants.
A novel electro-Fenton system was constructed by etching graphite felt with transition metal oxides, adding silicone oil to the channels, and using an ion exchange membrane as a solid electrolyte.
It improves oxygen diffusion flux and catalyst pore hydrophobicity, enhances reactive oxygen formation capacity, improves the efficiency of organic pollutant degradation, avoids secondary pollution from liquid electrolytes, and is low in cost and easy to mass-produce.
Smart Images
Figure CN119330468B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of organic wastewater treatment technology, and specifically relates to a method for preparing and applying an electro-Fenton composite electrode containing silicone oil. Background Technology
[0002] Electro-Fenton technology is an advanced wastewater treatment technology that relies on clean electrons to induce the generation of highly oxidizing reactive groups, which then attack recalcitrant organic pollutants, oxidizing them into low-toxicity or non-toxic small molecules. This technology is particularly suitable for treating biodegradable organic pollutants. Electro-Fenton technology can generate hydrogen peroxide in situ and activate it into hydroxyl radicals. This process is rapid, environmentally friendly, and requires no special equipment. It shows great promise for application in the field of organic wastewater treatment.
[0003] Currently, the cathode materials used in electro-Fenton technology are mainly composed of carbon materials, which possess advantages such as high conductivity, good stability, low cost, and environmental friendliness. However, unmodified carbon materials lack active sites, resulting in low hydrogen peroxide yield. Therefore, modification of carbon materials is necessary to improve their physical and chemical properties. Choosing to etch carbon materials with transition metal oxides as the cathode material not only increases the specific surface area of the carbon material, making its surface rougher and providing more active sites, but also promotes oxygen adsorption and reactive oxygen species formation, thereby facilitating the oxidative degradation of organic pollutants. Under flooded conditions, due to the low solubility of oxygen in water, it is difficult to transport oxygen to the electrode channels through water, which is detrimental to hydrogen peroxide formation and organic pollutant degradation. Another limiting factor for electro-Fenton technology in treating organic wastewater is the need for a high conductivity solution. This can generally be achieved by adding liquid electrolytes to the water to increase the conductivity, but this leads to secondary pollution and increased costs.
[0004] This invention uses an ion-exchange membrane as a solid electrolyte to replace the traditional liquid electrolyte, constructing a novel electro-Fenton technology to eliminate secondary pollution caused by liquid electrolytes and applying it to the treatment of organic wastewater. High-efficiency cathode materials are prepared by etching graphite felt with transition metal oxides at high temperatures. Adding silicone oil to the pores of the cathode material increases oxygen diffusion flux and hydrophobicity of the catalyst pores, thereby improving the electrode's resistance to flooding and promoting the formation of reactive oxygen species and the degradation of organic pollutants. Therefore, this invention has broad application prospects in the field of organic wastewater treatment. Summary of the Invention
[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a method for preparing an electro-Fenton composite electrode containing silicone oil, which can then be applied to the treatment of organic wastewater. The composite electrode prepared by this method exhibits high current efficiency, low oxygen diffusion resistance, and good flood resistance. Furthermore, the process is simple, low-cost, environmentally friendly, and easy for large-scale production.
[0006] The technical solution of this invention is: to prepare a high-efficiency cathode material by etching graphite felt with transition metal oxides at high temperature, and to add silicone oil, select an ion exchange membrane as a solid electrolyte, construct a novel electro-Fenton technology system, and apply it to the treatment of organic wastewater.
[0007] This invention relates to a method for preparing and applying an electro-Fenton composite electrode containing silicone oil, comprising the following steps:
[0008] (1) The graphite felt with a thickness of 0.2 cm was washed with ethanol and deionized water and dried. Then, it was immersed in a solution of acetate of transition metal with a molar concentration of 5.0 mmol / L and ultrasonically treated for 30 min. After the graphite felt was taken out and dried naturally, it was placed in a muffle furnace and calcined at 300 °C for 1.0 h. Then, the temperature was raised to 400 °C and calcined for 1.0 h to obtain graphite felt cathode material etched with transition metal oxide.
[0009] The acetate of the transition metal is any one or two of iron acetate, cobalt acetate, or manganese acetate;
[0010] (2) Add silicone oil to n-hexane, wherein the mass percentage concentration of silicone oil is 2.0~10.0%, sonicate for 10 min, then immerse the graphite felt etched by transition metal oxide in the above mixture and sonicate for 30 min, then vacuum dry at 80 °C for 2.0 h, and finally calcine at 200 °C for 1.0 h to obtain an electro-Fenton composite electrode containing silicone oil;
[0011] The silicone oil is any one of dimethyl silicone oil, methyl hydrogen silicone oil, methyl phenyl silicone oil, methyl ethoxy silicone oil, methyl vinyl silicone oil, or methyl hydroxy silicone oil;
[0012] (3) Immerse the ion exchange membrane in 5.0% hydrogen peroxide solution and treat it at 80 °C for 1.0 h. After washing with deionized water, place the membrane in 0.5 mol / L sulfuric acid solution and treat it at 80 °C for 2.0 h. Finally, put the membrane into deionized water and treat it at 80 °C for 2.0 h.
[0013] The ion exchange membrane is any one of Nafion N324, Nafion N117 or Nafion N438;
[0014] (4) At room temperature, an electro-Fenton wastewater treatment device is assembled with an acrylic sheet as the frame, a stainless steel mesh as the current collector, an electro-Fenton composite electrode containing silicone oil as the cathode, a ruthenium-iridium-titanium plate as the anode, and an ion exchange membrane as the solid electrolyte. Organic wastewater is treated under certain current density and aeration conditions. Samples are taken at certain intervals for analysis to calculate the degradation rate of organic pollutants in the wastewater.
[0015] The advantages of this invention over existing technologies are mainly reflected in:
[0016] (1) The present invention selects to etch graphite felt with transition metal oxides to form a large number of defects and porous structures on its surface, providing more active sites, which is beneficial to oxygen adsorption, reactive oxygen formation and oxidative degradation of organic pollutants.
[0017] (2) Adding silicone oil to the pores of graphite felt etched with transition metal oxides can improve the oxygen diffusion flux and the hydrophobicity of the catalyst pores, promote the improvement of the electrode's resistance to water flooding, and thus facilitate the formation of active oxygen and the degradation of organic pollutants.
[0018] (3) Using ion exchange membranes as solid electrolytes to replace traditional liquid electrolytes, a new type of electro-Fenton technology is constructed, which eliminates the secondary pollution caused by liquid electrolytes.
[0019] (4) The composite electrode prepared by the present invention has the advantages of low cost, good cycle stability, low oxygen mass transfer resistance, no secondary pollution, simple operation and high organic wastewater degradation efficiency. Attached Figure Description
[0020] Figure 1 This is a schematic diagram of the electric Fenton device assembled in Example 1.
[0021] Figure 2 The image shown is a scanning electron microscope (SEM) image of the composite electrode prepared in Example 1. Detailed Implementation
[0022] The specific embodiments of the present invention will be further explained below, but the scope of protection of the present invention is not limited thereto. Example 1
[0023] A graphite felt with a thickness of 0.2 cm was washed with ethanol and deionized water and dried. Then, it was immersed in a cobalt acetate solution with a molar concentration of 5.0 mmol / L and ultrasonically treated for 30 min. After the graphite felt was removed and dried naturally, it was placed in a muffle furnace and calcined at 300 °C for 1.0 h, and then heated to 400 °C for 1.0 h to obtain a cobalt tetroxide-etched graphite felt cathode material.
[0024] Dimethyl silicone oil was added to n-hexane at a mass percentage concentration of 2.0%, and ultrasonically treated for 10 min. Then, the etched graphite felt was immersed in the above mixture and ultrasonically treated for 30 min. Subsequently, it was vacuum dried at 80 °C for 2.0 h and finally calcined at 200 °C for 1.0 h to obtain an electro-Fenton composite electrode containing silicone oil.
[0025] The Nafion N324 ion exchange membrane was immersed in a 5.0% hydrogen peroxide solution and treated at 80 °C for 1.0 h. After washing with deionized water, the membrane was placed in a 0.5 mol / L sulfuric acid solution and treated at 80 °C for 2.0 h. Finally, the membrane was placed in deionized water and treated at 80 °C for 2.0 h.
[0026] At room temperature, an electro-Fenton wastewater treatment device was assembled using an acrylic sheet as the frame, a stainless steel mesh as the current collector, a silicone oil-containing Fenton composite electrode with a length, width, and thickness of 2.0 cm, 2.0 cm, and 0.2 cm as the cathode, a ruthenium-iridium-titanium plate as the anode, and Nafion N324 as the solid electrolyte. This device treated 100 mL of 20 mg / L Orange II dye wastewater at a current density of 3.0 mA / cm². 2 At a flow rate of 10 mL / min, the degradation rate of Orange II in the wastewater was 96.6% after 90 min. Under the same experimental conditions, when etched graphite felt without silicone oil was used as the cathode, the degradation rate of Orange II in the wastewater was 86.1%. Example 2
[0027] A graphite felt with a thickness of 0.2 cm was washed with ethanol and deionized water and dried. Then, it was immersed in a 5.0 mmol / L iron acetate solution and sonicated for 30 min. After the graphite felt was removed and dried naturally, it was placed in a muffle furnace and calcined at 300 °C for 1.0 h, and then calcined at 400 °C for 1.0 h to obtain an iron oxide etched graphite felt cathode material.
[0028] Methyl hydrogen-containing silicone oil was added to n-hexane, wherein the mass percentage concentration of methyl hydrogen-containing silicone oil was 5.0%, and ultrasonic treatment was performed for 10 min. Then, the etched graphite felt was immersed in the above mixture and ultrasonically treated for 30 min. Subsequently, it was vacuum dried at 80 °C for 2.0 h, and finally calcined at 200 °C for 1.0 h to obtain an electro-Fenton composite electrode containing silicone oil.
[0029] The Nafion N324 ion exchange membrane was immersed in a 5.0% hydrogen peroxide solution and treated at 80 °C for 1.0 h. After washing with deionized water, the membrane was placed in a 0.5 mol / L sulfuric acid solution and treated at 80 °C for 2.0 h. Finally, the membrane was placed in deionized water and treated at 80 °C for 2.0 h.
[0030] At room temperature, an electro-Fenton wastewater treatment device was assembled using an acrylic sheet as the frame, a stainless steel mesh as the current collector, a silicone oil-containing Fenton composite electrode with a length, width, and thickness of 2.0 cm, 2.0 cm, and 0.2 cm as the cathode, a ruthenium-iridium-titanium plate as the anode, and Nafion N324 as the solid electrolyte. This device treated 100 mL of 20 mg / L Orange II dye wastewater at a current density of 3.0 mA / cm². 2 At a flow rate of 10 mL / min, the degradation rate of Orange II in the wastewater was 88.5% after 90 min. Under the same experimental conditions, when silicone oil-free etched graphite felt was used as the cathode, the degradation rate of Orange II in the wastewater was 83.7%. Example 3
[0031] A graphite felt with a thickness of 0.2 cm was washed with ethanol and deionized water and dried. Then, it was immersed in a cobalt acetate solution with a molar concentration of 5.0 mmol / L and ultrasonically treated for 30 min. After the graphite felt was removed and dried naturally, it was placed in a muffle furnace and calcined at 300 °C for 1.0 h, and then heated to 400 °C for 1.0 h to obtain a cobalt tetroxide-etched graphite felt cathode material.
[0032] Methylphenyl silicone oil was added to n-hexane, wherein the mass percentage concentration of methylphenyl silicone oil was 2.0%, and ultrasonic treatment was performed for 10 min. Then, the etched graphite felt was immersed in the above mixture and ultrasonically treated for 30 min. Subsequently, it was vacuum dried at 80 °C for 2.0 h and finally calcined at 200 °C for 1.0 h to obtain an electro-Fenton composite electrode containing silicone oil.
[0033] The Nafion N324 ion exchange membrane was immersed in a 5.0% hydrogen peroxide solution and treated at 80 °C for 1.0 h. After washing with deionized water, the membrane was placed in a 0.5 mol / L sulfuric acid solution and treated at 80 °C for 2.0 h. Finally, the membrane was placed in deionized water and treated at 80 °C for 2.0 h.
[0034] At room temperature, an electro-Fenton wastewater treatment device was assembled using an acrylic sheet as the frame, a stainless steel mesh as the current collector, a silicone oil-containing Fenton composite electrode with a length, width, and thickness of 2.0 cm, 2.0 cm, and 0.2 cm as the cathode, a ruthenium-iridium-titanium plate as the anode, and Nafion N324 as the solid electrolyte. This device treated 100 mL of 20 mg / L Orange II dye wastewater at a current density of 3.0 mA / cm². 2 At a flow rate of 10 mL / min, the degradation rate of Orange II in the wastewater was 93.3% after 90 min. Under the same experimental conditions, when etched graphite felt without silicone oil was used as the cathode, the degradation rate of Orange II in the wastewater was 86.1%. Example 4
[0035] A 0.2 cm thick graphite felt was washed with ethanol and deionized water and dried. Then, it was immersed in a mixed solution of 5.0 mmol / L cobalt acetate and 5.0 mmol / L manganese acetate and ultrasonicated for 30 min. After the graphite felt was removed and dried naturally, it was placed in a muffle furnace and calcined at 300 °C for 1.0 h, and then heated to 400 °C for 1.0 h to obtain a graphite felt cathode material etched with cobalt tetroxide and manganese dioxide.
[0036] Methyl ethoxy silicone oil was added to n-hexane, wherein the mass percentage concentration of methyl ethoxy silicone oil was 10.0%, and ultrasonic treatment was performed for 10 min. Then, the etched graphite felt was immersed in the above mixture and ultrasonically treated for 30 min. Subsequently, it was vacuum dried at 80 °C for 2.0 h, and finally calcined at 200 °C for 1.0 h to obtain an electro-Fenton composite electrode containing silicone oil.
[0037] The Nafion N117 ion exchange membrane was immersed in a 5.0% hydrogen peroxide solution and treated at 80 °C for 1.0 h. After washing with deionized water, the membrane was placed in a 0.5 mol / L sulfuric acid solution and treated at 80 °C for 2.0 h. Finally, the membrane was placed in deionized water and treated at 80 °C for 2.0 h.
[0038] At room temperature, an electro-Fenton composite electrode containing silicone oil was assembled using an acrylic sheet as the frame, a stainless steel mesh as the current collector, a ruthenium-iridium-titanium plate as the anode, and Nafion N117 as the solid electrolyte. The electrode was used to treat 100 mL of 20 mg / L Orange II dye wastewater at a current density of 3.0 mA / cm². 2 At a flow rate of 10 mL / min, the degradation rate of Orange II in the wastewater was 85.4% after 90 min. Under the same experimental conditions, when silicone oil-free etched graphite felt was used as the cathode, the degradation rate of Orange II in the wastewater was 88.2%. Example 5
[0039] A graphite felt with a thickness of 0.2 cm was washed with ethanol and deionized water and dried. Then, it was immersed in a cobalt acetate solution with a molar concentration of 5.0 mmol / L and ultrasonically treated for 30 min. After the graphite felt was removed and dried naturally, it was placed in a muffle furnace and calcined at 300 °C for 1.0 h, and then heated to 400 °C for 1.0 h to obtain a cobalt tetroxide-etched graphite felt cathode material.
[0040] Methyl vinyl silicone oil was added to n-hexane, wherein the mass percentage concentration of methyl vinyl silicone oil was 2.0%, and ultrasonic treatment was performed for 10 min. Then, the etched graphite felt was immersed in the above mixture and ultrasonically treated for 30 min. Subsequently, it was vacuum dried at 80 °C for 2.0 h, and finally calcined at 200 °C for 1.0 h to obtain an electro-Fenton composite electrode containing silicone oil.
[0041] The Nafion N438 ion exchange membrane was immersed in a 5.0% hydrogen peroxide solution and treated at 80 °C for 1.0 h. After washing with deionized water, the membrane was placed in a 0.5 mol / L sulfuric acid solution and treated at 80 °C for 2.0 h. Finally, the membrane was placed in deionized water and treated at 80 °C for 2.0 h.
[0042] At room temperature, an electro-Fenton composite electrode containing silicone oil was assembled using an acrylic sheet as the frame, a stainless steel mesh as the current collector, a ruthenium-iridium-titanium plate as the anode, and Nafion N438 as the solid electrolyte. The electrode was used to treat 100 mL of 20 mg / L Orange II dye wastewater at a current density of 3.0 mA / cm². 2 At a flow rate of 10 mL / min, the degradation rate of Orange II in the wastewater was 92.5% after 90 min. Under the same experimental conditions, when etched graphite felt without silicone oil was used as the cathode, the degradation rate of Orange II in the wastewater was 85.4%. Example 6
[0043] A graphite felt with a thickness of 0.2 cm was washed with ethanol and deionized water and dried. Then, it was immersed in a manganese acetate solution with a molar concentration of 5.0 mmol / L and ultrasonically treated for 30 min. After the graphite felt was removed and dried naturally, it was placed in a muffle furnace and calcined at 300 ℃ for 1.0 h, and then heated to 400 ℃ for 1.0 h to obtain a graphite felt cathode material etched with manganese dioxide.
[0044] Methyl hydroxy silicone oil was added to n-hexane, wherein the mass percentage concentration of methyl hydroxy silicone oil was 2.0%, and ultrasonic treatment was performed for 10 min. Then, the etched graphite felt was immersed in the above mixture and ultrasonically treated for 30 min. Subsequently, it was vacuum dried at 80 °C for 2.0 h and finally calcined at 200 °C for 1.0 h to obtain an electro-Fenton composite electrode containing silicone oil.
[0045] The Nafion N324 ion exchange membrane was immersed in a 5.0% hydrogen peroxide solution and treated at 80 °C for 1.0 h. After washing with deionized water, the membrane was placed in a 0.5 mol / L sulfuric acid solution and treated at 80 °C for 2.0 h. Finally, the membrane was placed in deionized water and treated at 80 °C for 2.0 h.
[0046] At room temperature, an electro-Fenton wastewater treatment device was assembled using an acrylic sheet as the frame, a stainless steel mesh as the current collector, a silicone oil-containing Fenton composite electrode with a length, width, and thickness of 2.0 cm, 2.0 cm, and 0.2 cm as the cathode, a ruthenium-iridium-titanium plate as the anode, and Nafion N324 as the solid electrolyte. This device treated 100 mL of 20 mg / L Orange II dye wastewater at a current density of 3.0 mA / cm². 2 At a flow rate of 10 mL / min, the degradation rate of Orange II in the wastewater was 90.1% after 90 min. Under the same experimental conditions, when etched graphite felt without silicone oil was used as the cathode, the degradation rate of Orange II in the wastewater was 84.6%.
Claims
1. A method for preparing an electro-Fenton composite electrode containing silicone oil, characterized in that: Follow these steps: (1) The graphite felt with a thickness of 0.2 cm was washed with ethanol and deionized water and dried. Then, it was immersed in a solution of acetate of transition metal with a molar concentration of 5.0 mmol / L and ultrasonically treated for 30 min. After the graphite felt was taken out and dried naturally, it was placed in a muffle furnace and calcined at 300 °C for 1.0 h. Then, the temperature was raised to 400 °C and calcined for 1.0 h to obtain graphite felt cathode material etched with transition metal oxide. (2) Add silicone oil to n-hexane, wherein the mass ratio concentration of silicone oil is 2.0~10.0%, sonicate for 10 min, then immerse the graphite felt etched by transition metal oxide in the above mixture and sonicate for 30 min, then vacuum dry at 80 °C for 2.0 h, and finally calcine at 200 °C for 1.0 h to obtain an electro-Fenton composite electrode containing silicone oil; (3) Immerse the ion exchange membrane in 5.0% hydrogen peroxide solution and treat it at 80 °C for 1.0 h. After washing with deionized water, place the membrane in 0.5 mol / L sulfuric acid solution and treat it at 80 °C for 2.0 h. Finally, put the membrane into deionized water and treat it at 80 °C for 2.0 h. The acetate of the transition metal mentioned in step (1) is any one or two of iron acetate, cobalt acetate, or manganese acetate; The silicone oil mentioned in step (2) is any one of dimethyl silicone oil, methyl hydrogen silicone oil, methyl phenyl silicone oil, methyl ethoxy silicone oil, methyl vinyl silicone oil or methyl hydroxy silicone oil; The ion exchange membrane mentioned in step (3) is any one of Nafion N324, Nafion N117 or Nafion N438.
2. The application of the silicone oil-containing electro-Fenton composite electrode obtained by the method according to claim 1, characterized in that: At room temperature, an electro-Fenton wastewater treatment device was assembled using an acrylic sheet as a frame, a stainless steel mesh as a current collector, an electro-Fenton composite electrode containing silicone oil as a cathode, a ruthenium-iridium-titanium plate as an anode, and an ion exchange membrane as a solid electrolyte. Organic wastewater was treated under certain current density and aeration conditions. Samples were taken and analyzed at regular intervals to calculate the degradation rate of organic pollutants in the wastewater.