CN103446699A - Method for cooperatively degrading organic matters by visible light photoelectric-Fenton - Google Patents

Abstract

The invention discloses a method for synergistically degrading organic matter by using visible light photoelectricity-Fenton. It is a visible light photoelectricity-Fenton system composed of visible light, photocatalysis and electro-Fenton. Organic matter is placed in the system for degradation. The specific operation steps As follows: (1) Preparation of mesoporous TiO ₂ thin film electrodes; (2) Composition of visible light photoelectricity-Fenton system; (3) Degradation of organic matter. The present invention combines photocatalysis, electrochemical oxidation, and Fenton oxidation technology, and introduces visible light to form a visible light photoelectric-Fenton system. The self-made mesoporous _TiO2 thin film electrode is used in the visible light photoelectric-Fenton system to achieve The synergistic effect of photocatalysis and electro-Fenton improves the treatment effect of the whole system on organic pollutants.

Description

Synergistic Degradation of Organic Compounds Using Visible Light Photoelectricity-Fenton

technical field

The invention belongs to the field of environmental protection and governance, and relates to a method for degrading organic matter by using a visible light photoelectric-Fenton system.

Background technique

Photocatalysis has been widely used in the degradation of organic matter in the environment. Nano-TiO ₂ photocatalysts are favored by researchers due to their good catalytic performance, non-toxicity, and low price. The traditional TiO ₂ photocatalyst is in the form of powder, which has problems such as difficult separation of the catalyst and easy to cause secondary pollution. Mesoporous TiO ₂ , due to its high specific surface area, ordered pore structure, controllable pore size, and easy surface modification, can solve the problems of difficult catalyst separation and secondary pollution in traditional TiO ₂ photocatalysis. .

Patent 200910306567.0 discloses the preparation method and application of zinc ferrite/titanium dioxide nanocomposite visible light photocatalyst, which belongs to the technical field of environmental pollution control. Catalyst preparation includes the following steps: (1) Electrochemical oxidation reaction occurs under the action of hydrofluoric acid with a concentration of 0.2wt% to prepare titanium dioxide nanotube electrodes. The nanotube diameter is about 80nm and the tube length is 550mm; (2) using Zinc ferrite/titanium dioxide nanocomposite visible light photocatalyst prepared by new electrodeposition method. The method makes the inside of the synthesized ZnFe ₂ O ₄ nanotube, thereby reducing particle accumulation on the surface of the nanotube, and further improving electron transfer efficiency. In addition, the recombination of zinc ferrite reduces the disadvantage of high recombination probability of photogenerated electron-hole pairs to a certain extent, and also broadens the photoresponse range of titanium dioxide nanotube electrodes, improving its resistance to organic pollutants in the visible light range. Photocatalytic degradation efficiency. However, the problem of low photocatalytic efficiency has not been resolved. Some scholars have begun to study the combination of photocatalysis and other advanced oxidation technologies to improve photocatalytic efficiency through coordination. Among them, photocatalysis and electro-Fenton technology are combined to form a photoelectric-Fenton system. Using this system to treat pollutants is a new technology that has gradually entered people's field of vision in recent years. The proposal of the photoelectric-Fenton system improves the efficiency of photocatalysis, and the removal ability of the whole system for pollutants is also improved. At the same time, the combination of the two systems works synergistically to treat organic pollutants.

Patent 201010107539.9 discloses a process method for treating biochemically refractory organic wastewater. This method mainly uses ultraviolet light, electrochemistry, ultrasonic waves and redox chemical reactions to treat refractory organic wastewater, and passes the wastewater into the ultrasonic cavitation zone. The three reaction units in the electrochemical reaction area and the ultraviolet photocatalytic reaction area can realize the efficient combination of ultrasonic treatment of wastewater, ultraviolet light and Fenton reagent oxidation treatment of wastewater, and electrochemical and its cooperation with Fenton reagent oxidation treatment of wastewater. The multi-stage deep wastewater oxidation reaction can effectively treat a variety of biochemically refractory organic wastewater. However, this method is still limited to the use of ultraviolet light. The cost of ultraviolet light is high, it is easy to cause damage to the human body, and it only accounts for a small part of sunlight. These inevitable disadvantages will hinder the further application of this method.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art and provide a method for degrading organic matter with a visible light photoelectric-Fenton system that can improve photocatalytic efficiency and reduce the treatment cost of electro-Fenton.

The present invention is realized through the following technical solutions:

A method for synergistically degrading organic matter with visible light photoelectricity-Fenton, which is a visible light photoelectricity-Fenton system composed of visible light, photocatalysis and electro-Fenton, and organic matter is placed in the system for degradation. The specific operation steps are as follows:

(1) Preparation of mesoporous TiO ₂ thin film electrodes: The Ti-based substrates are sequentially polished, chemically polished, and ultrasonically cleaned, and then the treated Ti-based substrates are used as anodes, graphite or Pt electrodes are used as cathodes, fluorine-containing inorganic aqueous solutions or The fluorine-containing organic solution is used as the electrolyte solution, and the amorphous mesoporous TiO ₂ thin film electrode is obtained after electrochemical anodic oxidation; after high-temperature calcination in a tubular resistance furnace, the mesoporous TiO ₂ with a certain crystal form is obtained Thin film electrode, spare;

(2) To form a visible light photoelectric-Fenton system: the mesoporous TiO ₂ thin film electrode obtained in step (1) was used as the anode, and the carbonaceous material was used as the cathode. Illuminated to form a visible light photoelectric-Fenton system;

(3) Degradation of organic matter: the refractory organic matter is placed in the visible light photoelectric-Fenton system obtained in step (2) for degradation.

In the above-mentioned step (1), the sandpaper used in the grinding is 500#, 1000#, and 1500# metallographic sandpaper, which are polished successively.

In the above step (1), the polishing liquid used in the chemical polishing is composed of the following raw materials and the volume ratio is HF:HNO ₃ :H ₂ O=1:4:5.

In the above step (1), the fluorine-containing inorganic aqueous solution is HF solution, and the mass concentration of HF is 0.2-0.5 wt%; the fluorine-containing organic solution is NH ₄ F and glycerol The mixed liquid, the volume ratio of glycerol and water in the fluorine-containing organic solution is 1:9, and the mass concentration of NH ₄ F is 0.2-0.5 wt%.

In the above-mentioned step (1), the control voltage in the electrochemical anodizing method is 10-40V, the plate distance between the anode and the cathode is 3-5cm, and the anodizing time is 30-150min.

In the above-mentioned step (1), the tube-type resistance furnace controls the heating rate to be 20°C/min, the calcination temperature is 400-700°C, and the calcination time is 60-180 min.

In the above step (2), the carbonaceous material is graphite or activated carbon fiber. .

In the above step (2), the plate spacing between the anode and the cathode is 3-7 cm, and the anode voltage is controlled to be 10-40V.

In the above step (2), the aeration control aeration rate is 0.5~2 L/min; the pH of the visible light photoelectric-Fenton system is 2~4, and the supporting electrolyte is Na ₂ SO ₄ , The dosage is 5 ~ 10 g/L; the dosage of Fe ²⁺ is 0.1 ~ 1 mM.

In the above step (2), the visible light irradiation is an external illumination type, and the light source is a xenon lamp light source.

Advantage and positive effect of the present invention relative to prior art are as follows:

1. The present invention prepares mesoporous _TiO2 thin film on Ti base material by anodic oxidation method, can prepare mesoporous _TiO2 thin film with regular shape and uniform size, easy to operate and easy to control conditions; replace with mesoporous _TiO2 thin film The vertical structure of the traditional powder TiO ₂ and mesoporous TiO ₂ film provides a more convenient channel for the transmission and diffusion of electrons, reduces the recombination of photogenerated electrons and holes, and also solves the problem of powder TiO ₂ Catalysts are difficult to separate and easily cause secondary pollution.

2. The present invention combines mesoporous _TiO2 thin film photocatalysis with electro-Fenton technology. The combination of the two systems, synergistic effect, greatly improves the degradation ability of organic pollutants, not only improves the photocatalytic efficiency, but also to a certain extent Reduced power consumption on the Electric-Fenton.

3. The present invention introduces visible light, which avoids potential safety hazards when using ultraviolet light, and reduces the required cost accordingly. At the same time, this system has a positive guiding effect on the utilization of solar energy, and has certain industrial promotion value.

Description of drawings

Fig. 1 is the FE-SEM picture of the mesoporous _TiO2 film electrode that is made under the experimental condition in example 1.

Fig. 2 is the XRD figure of the mesoporous _TiO2 film electrode that is made under experimental conditions in example 1

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

Example 1:

Polish the Ti-based substrate with a purity >99.6% with metallographic sandpaper of 500#, 1000#, and 1500# in sequence until the surface is smooth, and then immerse it in a solution with a volume ratio of HF:HNO ₃ :H ₂ O=1:4:5. Chemical polishing was carried out in the polishing solution for 30 s, and then cleaned with acetone and pure water in an ultrasonic cleaner. The treated Ti-based substrate was used as the anode, and the graphite electrode was used as the cathode. The distance between the anode and the cathode was 4 cm. A mixed solution of NH ₄ F and glycerin was used as the electrolyte, and the volume ratio of glycerol to water was 1:9. , containing NH ₄ F at a concentration of 0.5 wt%. Use copper wires as wires to connect the two stages to a DC stabilized power supply for electrochemical anodic oxidation. In this reaction, the controlled voltage was 30 V, and the anodic oxidation time was 90 min to obtain an amorphous mesoporous TiO ₂ thin film electrode; After calcination for 120 min, a mesoporous _TiO2 thin film electrode with a certain crystal form was obtained.

The prepared mesoporous _TiO2 thin film electrode was used as the anode, the graphite was used as the cathode, and the rectangular PVC tank was used as the electrolytic reaction tank. The plate distance between the anode and the cathode is 5 cm, the anode voltage is controlled at 30 V, the cathode is aerated through the aeration device, the aeration rate is controlled at 1.5 L/min, and the visible light irradiation is 150 W xenon lamp, forming a visible light photoelectric - Fenton system.

20 mg/L Rhodamine B was used as an organic pollutant that needs to be degraded, and it was put into the visible light photoelectric-Fenton system for degradation reaction. During the reaction process, constant stirring was maintained. The pH of the reaction solution in this system was 3, and the supporting electrolyte was Na The dosage of ₂ SO ₄ is 5 g/L; the dosage of Fe ²⁺ is 1 mM. Visible light photocatalysis (lighting, no electricity, aeration, no Fe ^2+, ), electric Fenton (no light, electricity, aeration, Fe ²⁺ ), photoelectric Fenton test (lighting, electricity , aeration, Fe ^{2+ ,} ), kept stirring at a constant speed during the reaction process, the removal rates of rhodamine B in 30 minutes were 2.78%, 30.87%, 69.92% Electro-Fenton system summation improved by 108%.

Example 2:

Polish the Ti-based substrate with a purity >99.6% with metallographic sandpaper of 500#, 1000#, and 1500# in sequence until the surface is smooth, and then immerse it in a solution with a volume ratio of HF:HNO ₃ :H ₂ O=1:4:5. Chemical polishing was carried out in the polishing solution for 30 s, and then cleaned with acetone and pure water in an ultrasonic cleaner. The treated Ti-based substrate is used as the anode, and the graphite electrode is used as the cathode. The distance between the anode and the cathode is 5 cm. A mixed solution of NH ₄ F and glycerin is used as the electrolyte, and the volume ratio of glycerol to water is 1:9. , containing NH ₄ F at a concentration of 0.3wt%. Use copper wires as wires to connect the two stages to a DC stabilized power supply for electrochemical anodic oxidation. In this reaction, the control voltage was 10 V, and the anodic oxidation time was 150 min to obtain an amorphous mesoporous TiO ₂ thin film electrode; After calcination for 180 min, a mesoporous TiO ₂ thin film electrode with a certain crystal form was obtained.

The prepared mesoporous _TiO2 thin film electrode was used as the anode, the activated carbon fiber was used as the cathode, and the rectangular PVC tank was used as the electrolytic reaction tank. The plate distance between the anode and the cathode is 3 cm, the anode voltage is controlled at 10 V, the cathode is aerated through the aeration device, the aeration rate is controlled at 0.5 L/min, and the visible light irradiation is 150 W xenon lamp, forming a visible light photoelectric- Fenton system.

20 mg/L Rhodamine B was used as an organic pollutant that needs to be degraded, and it was put into the visible light photoelectric-Fenton system for degradation reaction. During the reaction process, constant stirring was maintained. The pH of the reaction solution in this system was 4, and the supporting electrolyte was Na The dosage of ₂ SO ₄ is 10 g/L; the dosage of Fe ²⁺ is 0.1 mM. Visible light photocatalysis (lighting, no electricity, aeration, no Fe ^2+, ), electric Fenton (no light, electricity, aeration, Fe ²⁺ ), photoelectric Fenton test (lighting, electricity , aeration, Fe ^{2+ ,} ), kept stirring at a constant speed during the reaction process, the removal rates of rhodamine B in 30 minutes were 2.71%, 39.89%, 65.72% The addition of the electro-Fenton system increased by 54.3%.

Example 3:

Polish the Ti-based substrate with a purity >99.6% with metallographic sandpaper of 500#, 1000#, and 1500# in sequence until the surface is smooth, and then immerse it in a solution with a volume ratio of HF:HNO ₃ :H ₂ O=1:4:5. Chemical polishing was carried out in the polishing solution for 30 s, and then cleaned with acetone and pure water in an ultrasonic cleaner. The treated Ti-based substrate was used as the anode, and the graphite electrode was used as the cathode. The distance between the anode and the cathode was 3 cm. A mixed solution of NH ₄ F and glycerin was used as the electrolyte, and the volume ratio of glycerol to water was 1:9. , containing NH ₄ F at a concentration of 0.2wt%. Use copper wires as wires to connect the two stages to a DC stabilized power supply for electrochemical anodic oxidation. In this reaction, the control voltage was 40 V, and the anodic oxidation time was 90 min to obtain an amorphous mesoporous TiO ₂ thin film electrode; After calcination for 120 min, a mesoporous _TiO2 thin film electrode with a certain crystal form was obtained.

The prepared mesoporous _TiO2 thin film electrode was used as the anode, the graphite was used as the cathode, and the rectangular PVC tank was used as the electrolytic reaction tank. The plate distance between the anode and the cathode is 4 cm, the anode voltage is controlled at 40 V, the cathode is aerated through the aeration device, the aeration rate is controlled at 1 L/min, and the visible light irradiation is 150 W xenon lamp to form a visible light photoelectric- Fenton system.

20 mg/L Rhodamine B was used as an organic pollutant that needs to be degraded, and it was put into the visible light photoelectric-Fenton system for degradation reaction. During the reaction process, constant stirring was maintained. The pH of the reaction solution in this system was 2, and the supporting electrolyte was Na The dosage of ₂ SO ₄ is 8 g/L; the dosage of Fe ²⁺ is 0.5 mM. Visible light photocatalysis (lighting, no electricity, aeration, no Fe ^2+, ), electric Fenton (no light, electricity, aeration, Fe ²⁺ ), photoelectric Fenton test (lighting, electricity , aeration, Fe ^{2+ ,} ), kept stirring at a constant speed during the reaction process, the removal rates of Rhodamine B in 30 minutes were 2.91%, 33.74%, 69.52% The addition of the electro-Fenton system increased by 89.69%.

Example 4:

Polish the Ti-based substrate with a purity >99.6% with metallographic sandpaper of 500#, 1000#, and 1500# in sequence until the surface is smooth, and then immerse it in a solution with a volume ratio of HF:HNO ₃ :H ₂ O=1:4:5. Chemical polishing was carried out in the polishing solution for 30 s, and then cleaned with acetone and pure water in an ultrasonic cleaner. The treated Ti-based substrate was used as the anode, and the graphite electrode was used as the cathode. The distance between the anode and the cathode was 3 cm. A mixed solution of NH ₄ F and glycerin was used as the electrolyte, and the volume ratio of glycerol to water was 1:9. , containing NH ₄ F at a concentration of 0.4wt%. Use copper wires as wires to connect the two stages to a DC stabilized power supply for electrochemical anodic oxidation. In this reaction, the controlled voltage was 20 V, and the anodic oxidation time was 60 min to obtain an amorphous mesoporous TiO ₂ thin film electrode; After calcination for 60 min, a mesoporous TiO ₂ thin film electrode with a certain crystal form was obtained.

The prepared mesoporous _TiO2 thin film electrode was used as the anode, the graphite was used as the cathode, and the rectangular PVC tank was used as the electrolytic reaction tank. The plate distance between the anode and the cathode is 7 cm, the anode voltage is controlled to 20 V, the cathode is aerated through the aeration device, the aeration rate is controlled to 2 L/min, and the visible light irradiation is 150 W xenon lamp to form a visible light photoelectric- Fenton system.

20 mg/L Rhodamine B was used as an organic pollutant that needs to be degraded, and it was put into the visible light photoelectric-Fenton system for degradation reaction. During the reaction process, constant stirring was maintained. The pH of the reaction solution in this system was 3, and the supporting electrolyte was Na The dosage of ₂ SO ₄ is 5 g/L; the dosage of Fe ²⁺ is 1 mM. Visible light photocatalysis (lighting, no electricity, aeration, no Fe ^2+, ), electric Fenton (no light, electricity, aeration, Fe ²⁺ ), photoelectric Fenton test (lighting, electricity , aeration, Fe ^{2+ ,} ), kept stirring at a constant speed during the reaction process, the removal rates of Rhodamine B in 30 minutes were 5.43%, 30.31%, 67.35% The addition of the electro-Fenton system increased by 88.4%.

Example 5:

Polish the Ti-based substrate with a purity >99.6% with metallographic sandpaper of 500#, 1000#, and 1500# in sequence until the surface is smooth, and then immerse it in a solution with a volume ratio of HF:HNO ₃ :H ₂ O=1:4:5. Chemical polishing was carried out in the polishing solution for 30 s, and then cleaned with acetone and pure water in an ultrasonic cleaner. The treated Ti-based substrate was used as the anode, the Pt electrode was used as the cathode, the distance between the anode and the cathode was 4 cm, and HF aqueous solution was used as the electrolyte, where HF was 0.4 wt%. Use copper wires as wires to connect the two stages to a DC stabilized power supply for electrochemical anodic oxidation. In this reaction, the controlled voltage was 30 V, and the anodic oxidation time was 150 min to obtain an amorphous mesoporous TiO ₂ thin film electrode; After calcination for 120 min, a mesoporous _TiO2 thin film electrode with a certain crystal form was obtained.

The prepared mesoporous _TiO2 thin film electrode was used as the anode, the graphite was used as the cathode, and the rectangular PVC tank was used as the electrolytic reaction tank. The plate distance between the anode and the cathode is 5 cm, the anode voltage is controlled at 30 V, the cathode is aerated through the aeration device, the aeration rate is controlled at 1.5 L/min, and the visible light irradiation is 150 W xenon lamp, forming a visible light photoelectric- Fenton system.

20 mg/L Rhodamine B was used as an organic pollutant that needs to be degraded, and it was put into the visible light photoelectric-Fenton system for degradation reaction. During the reaction process, constant stirring was maintained. The pH of the reaction solution in this system was 3, and the supporting electrolyte was Na The dosage of ₂ SO ₄ is 5 g/L; the dosage of Fe ²⁺ is 1 mM. Visible light photocatalysis (lighting, no electricity, aeration, no Fe ^2+, ), electric Fenton (no light, electricity, aeration, Fe ²⁺ ), photoelectric Fenton test (lighting, electricity , aeration, Fe ^{2+ ,} ), kept stirring at a constant speed during the reaction process, the removal rates of Rhodamine B in 30 minutes were 4.56%, 37.87%, 67.16% The addition of the electro-Fenton system increased by 58.3%.

Embodiment 6:

Polish the Ti-based substrate with a purity >99.6% with metallographic sandpaper of 500#, 1000#, and 1500# in sequence until the surface is smooth, and then immerse it in a solution with a volume ratio of HF:HNO ₃ :H ₂ O=1:4:5. Chemical polishing was carried out in the polishing solution for 30 s, and then cleaned with acetone and pure water in an ultrasonic cleaner. The treated Ti-based substrate was used as the anode, the graphite electrode was used as the cathode, the distance between the anode and the cathode was 5 cm, and HF aqueous solution was used as the electrolyte, where HF was 0.5 wt%. Use copper wires as wires to connect the two stages to a DC stabilized power supply for electrochemical anodic oxidation. In this reaction, the control voltage is 10 V, and the anodic oxidation time is 30 min to obtain an amorphous mesoporous TiO ₂ thin film electrode; then it is calcined at a high temperature in a tubular resistance furnace with a heating rate of 20 ℃/min and a calcination temperature of 700 ℃ After 180 min, a mesoporous TiO ₂ thin film electrode with a certain crystal form was obtained.

The prepared mesoporous _TiO2 thin film electrode was used as the anode, the activated carbon fiber was used as the cathode, and the rectangular PVC tank was used as the electrolytic reaction tank. The plate distance between the anode and the cathode is 5 cm, the anode voltage is controlled at 10 V, the cathode is aerated through the aeration device, the aeration rate is controlled at 0.5 L/min, and the visible light irradiation is 150 W xenon lamp to form a visible light photoelectric- Fenton system.

20 mg/L Rhodamine B was used as an organic pollutant that needs to be degraded, and it was put into the visible light photoelectric-Fenton system for degradation reaction. During the reaction process, constant stirring was maintained. The pH of the reaction solution in this system was 4, and the supporting electrolyte was Na The dosage of ₂ SO ₄ is 10 g/L; the dosage of Fe ²⁺ is 0.1 mM. Visible light photocatalysis (lighting, no electricity, aeration, no Fe ^2+, ), electric Fenton (no light, electricity, aeration, Fe ²⁺ ), photoelectric Fenton test (lighting, electricity , aeration, Fe ^{2+ ,} ), kept stirring at a constant speed during the reaction process, the removal rates of rhodamine B in 30 minutes were 3.59%, 33.05%, 61.58% The addition of the electro-Fenton system increased by 68.1%.

Embodiment 7:

Polish the Ti-based substrate with a purity >99.6% with metallographic sandpaper of 500#, 1000#, and 1500# in sequence until the surface is smooth, and then immerse it in a solution with a volume ratio of HF:HNO ₃ :H ₂ O=1:4:5. Chemical polishing was carried out in the polishing solution for 30 s, and then cleaned with acetone and pure water in an ultrasonic cleaner. The treated Ti-based substrate was used as the anode, the Pt electrode was used as the cathode, the distance between the anode and the cathode was 3 cm, and HF aqueous solution was used as the electrolyte, where HF was 0.3 wt%. Use copper wires as wires to connect the two stages to a DC stabilized power supply for electrochemical anodic oxidation. In this reaction, the control voltage is 40 V, and the anodic oxidation time is 60 min to obtain an amorphous mesoporous TiO ₂ thin film electrode; then it is calcined at a high temperature in a tubular resistance furnace with a heating rate of 20 ℃/min and a calcination temperature of 400 ℃ After 60 min, a mesoporous TiO ₂ thin film electrode with a certain crystal form was obtained.

The prepared mesoporous _TiO2 thin film electrode was used as the anode, the graphite was used as the cathode, and the rectangular PVC tank was used as the electrolytic reaction tank. The plate distance between the anode and the cathode is 3 cm, the anode voltage is controlled to 40 V, the cathode is aerated through the aeration device, the aeration rate is controlled to 2 L/min, and the visible light irradiation is 150 W xenon lamp to form a visible light photoelectric- Fenton system.

20 mg/L Rhodamine B was used as an organic pollutant that needs to be degraded, and it was put into the visible light photoelectric-Fenton system for degradation reaction. During the reaction process, constant stirring was maintained. The pH of the reaction solution in this system was 2, and the supporting electrolyte was Na The dosage of ₂ SO ₄ is 8 g/L; the dosage of Fe ²⁺ is 1 mM. Visible light photocatalysis (lighting, no electricity, aeration, no Fe ^2+, ), electric Fenton (no light, electricity, aeration, Fe ²⁺ ), photoelectric Fenton test (lighting, electricity , aeration, Fe ^{2+ ,} ), kept stirring at a constant speed during the reaction process, the removal rates of rhodamine B in 30 minutes were 4.83%, 34.54%, 71.00%, respectively, and the removal rates of visible light photoelectric Fenton system were higher than The addition of the electro-Fenton system increased by 80.3%.

Example 8

Polish the Ti-based substrate with a purity >99.6% with metallographic sandpaper of 500#, 1000#, and 1500# in sequence until the surface is smooth, and then immerse it in a solution with a volume ratio of HF:HNO ₃ :H ₂ O=1:4:5. Chemical polishing was carried out in the polishing solution for 30 s, and then cleaned with acetone and pure water in an ultrasonic cleaner. The treated Ti-based substrate was used as the anode, the graphite electrode was used as the cathode, the distance between the anode and the cathode was 4 cm, and HF aqueous solution was used as the electrolyte, where HF was 0.2 wt%. Use copper wires as wires to connect the two stages to a DC stabilized power supply for electrochemical anodic oxidation. In this reaction, the control voltage was 30 V, and the anodic oxidation time was 90 min to obtain an amorphous mesoporous TiO ₂ thin film electrode; then it was calcined at a high temperature in a tubular resistance furnace with a heating rate of 20 ℃/min and a calcination temperature of 600 ℃ After 120 min, a mesoporous TiO ₂ thin film electrode with a certain crystal form was obtained.

The prepared mesoporous _TiO2 thin film electrode was used as the anode, the activated carbon fiber was used as the cathode, and the rectangular PVC tank was used as the electrolytic reaction tank. The plate distance between the anode and the cathode is 7 cm, the anode voltage is controlled at 30 V, the cathode is aerated through the aeration device, the aeration rate is controlled at 1.5 L/min, and the visible light irradiation is 150 W xenon lamp, forming a visible light photoelectric- Fenton system.

20 mg/L Rhodamine B was used as an organic pollutant that needs to be degraded, and it was put into the visible light photoelectric-Fenton system for degradation reaction. During the reaction process, constant stirring was maintained. The pH of the reaction solution in this system was 3, and the supporting electrolyte was Na The dosage of ₂ SO ₄ is 5 g/L; the dosage of Fe ²⁺ is 0.5 mM. Visible light photocatalysis (lighting, no electricity, aeration, no Fe ^2+, ), electric Fenton (no light, electricity, aeration, Fe ²⁺ ), photoelectric Fenton test (lighting, electricity , aeration, Fe ^{2+ ,} ), kept stirring at a constant speed during the reaction process, the removal rates of rhodamine B in 30 minutes were 3.23%, 36.33%, 63.24% The addition of the electro-Fenton system increased by 59.86%.

Claims (10)

1. one kind by visible ray photoelectricity-organic method of Fenton Synergistic degradation, it is characterized in that: it is the visible ray photoelectricity that utilizes visible ray, photocatalysis and electricity-Fenton to form-Fenton system, organic matter is placed in to this system and is degraded, its concrete operation step is as follows:

(1) prepare mesoporous TiO ₂membrane electrode: by the Ti substrate material polished successively, chemical polishing, Ultrasonic Cleaning process, then the Ti substrate material after processing is as anode, graphite or Pt electrode are as negative electrode, fluorine-containing inorganic aqueous solution or fluorine-containing organic solution are as electrolyte solution, after processing by electrochemistry anodic oxidation, obtain unformed mesoporous TiO ₂membrane electrode; After high-temperature calcination in tube type resistance furnace, obtain having the mesoporous TiO of certain crystal formation again ₂membrane electrode, standby;

(2) form visible ray photoelectricity-Fenton system: the mesoporous TiO that step (1) is obtained ₂membrane electrode is as anode, and carbonaceous material, as negative electrode, carries out aeration by the aerator target, applies DC voltage-stabilizing and visible ray irradiation simultaneously, forms visible ray photoelectricity-Fenton system;

(3) organic matter is degraded: the organic matter of difficult degradation is placed in to the visible ray photoelectricity that step (2) obtains-Fenton system and is degraded.

2. according to claim 1 by visible ray photoelectricity-organic method of Fenton Synergistic degradation, it is characterized in that: in step (1), the abrasive paper for metallograph that the sand paper that described polishing adopts is 500#, 1000#, 1500#, polishing successively.

3. according to claim 1 by visible ray photoelectricity-organic method of Fenton Synergistic degradation, it is characterized in that: in step (1), the polishing fluid that described chemical polishing adopts is HF: HNO by following raw material and volume ratio ₃: H ₂o=1: form at 4: 5.

4. according to claim 1 by visible ray photoelectricity-organic method of Fenton Synergistic degradation, it is characterized in that: in step (1), described fluorine-containing inorganic aqueous solution is HF solution, and the mass concentration of HF is 0.2 ~ 0.5 wt%; Described fluorine-containing organic solution is NH ₄the mixed liquor of F and glycerine, in fluorine-containing organic solution, the volume ratio of glycerine and water is 1: 9, contains NH ₄the mass concentration of F is 0.2 ~ 0.5 wt%.

5. according to claim 1 by visible ray photoelectricity-organic method of Fenton Synergistic degradation, it is characterized in that: in step (1), controlling voltage in described electrochemistry anodic oxidation is 10 ~ 40V, and the distance between plates of anode and negative electrode is 3 ~ 5cm, and anodizing time is 30 ~ 150min.

6. according to claim 1 by visible ray photoelectricity-organic method of Fenton Synergistic degradation, it is characterized in that: in step (1), it is 20 ℃/min that described tube type resistance furnace is controlled programming rate, and calcining heat is 400 ~ 700 ℃, and calcination time is 60 ~ 180 min.

7. according to claim 1 by visible ray photoelectricity-organic method of Fenton Synergistic degradation, it is characterized in that: in step (2), described carbonaceous material is graphite or NACF.

8. according to claim 1 by visible ray photoelectricity-organic method of Fenton Synergistic degradation, it is characterized in that: in step (2), described anode, the negative electrode distance between plates between them is 3 ~ 7cm, and the control anode voltage is 10 ~ 40V.

9. according to claim 1 by visible ray photoelectricity-organic method of Fenton Synergistic degradation, it is characterized in that: in step (2), described aeration control aeration rate is 0.5 ~ 2 L/min; The pH of described visible ray photoelectricity-Fenton system is 2 ~ 4, and the support electrolyte is Na ₂sO ₄, dosage is 5 ~ 10 g/L; Fe ²⁺dosage be 0.1 ~ 1 mM.

10. according to claim 1 by visible ray photoelectricity-organic method of Fenton Synergistic degradation, it is characterized in that: in step (2), described visible ray irradiation is external lighting type, and the employing light source is xenon source.

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