CN111547822A - High-catalytic-activity electrode and method for photoelectrocatalytic degradation of active red 195 by using same - Google Patents

Abstract

The invention discloses a high catalytic activity electrode and a method for degrading active red 195 through photoelectrocatalysis thereof, belonging to the technical field of photoelectrocatalysis. The electrode is prepared as follows: preparation of Ti/TiO by anodic oxidation₂NT is reduced and then calcined in nitrogen atmosphere to prepare black Ti/TiO₂NT(Ti/Black‑TiO₂NT), and depositing Ni on Ti/Black-TiO by adopting a pulse current deposition method₂On NT to obtain Ti/Black-TiO₂NT/Ni, subsequently microwave synthesized on Ti/Black-TiO₂MOF material ZIF-9 particles are loaded on NT/Ni to obtain Ti/Black-TiO₂NT/Ni/ZIF-9 electrode. The method for degrading the active red 195 by adopting the electrode comprises the steps of taking the electrode as an anode, taking a copper electrode as a cathode, adopting a constant-current constant-voltage power supply, adopting a 500W xenon lamp as a light source, controlling the temperature to be 25 ℃ and the current density to be 50mA/m²The degradation liquid is: 10mg/L active red 195, Ti/Black-TiO prepared by the invention₂The NT/Ni/ZIF-9 electrode has good electrode stability, and high catalytic efficiency when being used in the process of degrading dye active red 195.

Description

High-catalytic-activity electrode and method for photoelectrocatalytic degradation of active red 195 by using same

Technical Field

The invention belongs to the technical field of photoelectrocatalysis, and particularly relates to a high-catalytic-activity electrode and a method for photoelectrocatalysis degradation of active red 195 by the high-catalytic-activity electrode.

Background

Dyeing is the most important source of environmental pollution in the textile industry. These processes require large amounts of water and therefore produce large amounts of waste water. It is estimated that 10-15% of the dye is lost during dyeing and is discharged as waste liquid, causing serious pollution to the environment. Reactive red 195 is one of the organic dyes widely used for cotton dyeing and printing. The dye wastewater is common organic wastewater in industry, and has high BOD and COD, high chromaticity, complex chemical structure and biological toxicity of partial dye. It is difficult to completely remove them by conventional biochemical methods. The advanced oxidation technology (AOP) treatment by light, electrocatalytic oxidation and the like is one of the research hotspots of the current dye wastewater treatment technology. The photoelectrocatalysis oxidation technology has the advantages of simple and convenient operation, high degradation efficiency, good environmental compatibility and the like. Photoelectrode materials and catalytic materials are important determinants in photoelectrochemical processes and will directly affect the efficiency and energy consumption of photoelectrochemical processes. Therefore, the search and the research of the anode material with high catalytic activity and long service life are very important.

TiO₂Is one of the most widely used photocatalytic materials because it has excellent ability to oxidatively decompose organic pollutants, has corrosion resistance, is non-toxic and low-cost, and many studies have been focused on synthesizing TiO having various structures₂(e.g., nanotube arrays, nanorods, nanowires), wherein the TiO is highly ordered₂Nanotube arrays standing vertically on a Ti substrate in an ideal form to promote photocatalytic efficiency, and other TiO₂Compared with the structure, the nano-tube junctionThe improved structure provides a shorter carrier diffusion path, i.e., along the tube wall, thereby minimizing charge loss due to electron hopping between nanoparticles, and the nanotubes formed from the Ti substrate can also be used as electrodes, which can achieve high photocatalytic efficiency when a small potential is applied, compared to the stand-alone nanotubes. Most studied TiO₂The nanotubes are of anatase and rutile structure^[6]The anatase structure has a higher photocatalytic activity than the rutile form.

But TiO2₂The forbidden band width of the crystal is 3.2eV, and the TiO is limited₂Nanotubes are more widely used. TiO due to its large band gap width₂Nanotubes require UV light irradiation for photocatalysis, which accounts for only a small fraction (5%) of the solar spectrum compared to visible light (52%) and infrared light (43%), and furthermore, the rapid recombination of photogenerated electron-hole pairs also affects TiO₂One factor in the photocatalytic efficiency of nanotubes, and therefore both of these drawbacks must be addressed to enhance TiO enhancement₂Photocatalytic activity of the nanotubes.

In recent years, metal-organic framework Materials (MOFs) have attracted the attention of many scholars, and Zeolitic imidazole-like framework materials (Zeolitic imidazole frameworks ZIFs) are novel metal-organic framework coordination polymers having a zeolite topology, which combine the advantages of both zeolite and metal-organic framework materials, and have large specific surface area and high stability. Co-ZIF-9 is a zeolite-like structure novel material synthesized by taking Co as a metal node and benzimidazole as an organic ligand in an organic solvent DMF through a solvothermal method. TiO2₂Combined with metal-organic framework Materials (MOFs), the specific surface area can be increased, more active sites are provided, and the photoelectrocatalytic activity is improved.

Disclosure of Invention

1. Technical problem to be solved by the invention

The invention aims to overcome the defects of the prior art and provide a catalyst with high catalytic activityElectrode and method for preparing Ti/Black-TiO by microwave method through photoelectrocatalysis degradation of active red 195 by using same₂Compared with other methods, the NT/Ni/ZIF-9 electrode is simple to operate, improves the purity, density and uniformity of a deposited layer, reduces the void ratio, improves the stability and the photoelectric catalytic performance of the electrode, and is prepared from the Ti/Black-TiO₂The method provided by the invention has the advantages that the efficiency of removing the active red 195 by oxidative degradation is high, the electrode corrosion resistance is good, the stability of the degradation process is good, the degradation efficiency is higher than that of a common titanium dioxide nanotube electrode, the decolorization rate of the active red 195 reaches 99.1-99.9%, the degradation rate of COD reaches 95.8-97.2%, the degradation side reaction is less, the degradation high efficiency is ensured, and the method belongs to a green chemical part.

2. Technical scheme

In order to achieve the purpose, the technical scheme provided by the invention is as follows:

the invention relates to a high catalytic activity electrode, which adopts an anodic oxidation method to prepare Ti/TiO₂NT is reduced and then calcined in nitrogen atmosphere to prepare black Ti/TiO₂NT(Ti/Black-TiO₂NT), and depositing Ni on Ti/Black-TiO by adopting a pulse current deposition method₂On NT to obtain Ti/Black-TiO₂NT/Ni, subsequently microwave synthesized on Ti/Black-TiO₂MOF material ZIF-9 particles are loaded on NT/Ni to obtain Ti/Black-TiO₂NT/Ni/ZIF-9 electrode.

As a further improvement of the invention, the preparation method comprises the following specific steps:

the first step,

Selecting pure titanium metal as a titanium sheet, firstly polishing the titanium sheet by three different specifications of 600 meshes, 800 meshes and 1000 meshes of abrasive paper in sequence, then ultrasonically washing the polished titanium sheet in absolute ethyl alcohol, acetone and deionized water for 10min in sequence, then putting the titanium sheet into a mixed solution of ethylene glycol, hydrofluoric acid and secondary distilled water for corrosion treatment for 20min, wherein the surface of the corroded titanium sheet is a white pitted surface, and cleaning the corroded titanium sheet by using deionized water, wherein: hydrofluoric acid, wherein the volume ratio of the ethylene glycol to the secondary distilled water is 2: 6: 10;

step two,

Preparing Ti/TiO by anode oxidation method₂NT, 0.3-0.5 wt% NH and 2-5V% H at room temperature₂In O glycol electrolyte, a Ti sheet is used as an anode, a Cu sheet is used as a cathode, anodic electrooxidation is carried out, the oxidation voltage is 60-100V, the oxidation time is 7-10 h, magnetic stirring is carried out all the time in the oxidation process, a sample is soaked in absolute ethyl alcohol for 2h after the oxidation is finished, the absolute ethyl alcohol is used for carrying out ultrasonic cleaning for 2min, and then the temperature is controlled to be 2-4 mol.L^-1Na₂SO₄To Ti/TiO in solution₂Reduction of NT electrode to obtain Ti⁴⁺Reduction to Ti³⁺Finally, annealing treatment is carried out in the nitrogen atmosphere, the annealing temperature is 500-550 ℃, and heat preservation is carried out for 4 hours, so that the Ti/Black-TiO can be prepared₂An NT electrode;

step three,

Annealing the Ti/Black-TiO annealed in the second step₂The NT electrode is used as a working electrode, the Pt sheet is used as a counter electrode, the saturated calomel electrode is used as a reference electrode, and the electrode is placed in NiSO mixed with 200-400 g/L₄·6H₂O, NiCl of 20-41 g/L₂·6H₂O and 10-32 g/L H₃BO₃In the electroplating solution, the temperature is controlled to be 25 ℃, the stirring speed is 600rpm, and Ni is modified on the nanotube by pulse electrodeposition for 10min to prepare Ti/Black-TiO₂NT/Ni electrode;

step four,

0.1-0.7 g Co (NO)₃)₂And 0.5-0.8 g of benzimidazole is dissolved in 10-40 ml of N, N-dimethylformamide, and the Ti/Black-TiO is added₂Putting NT/Ni into the solution, then putting the solution into a microwave reactor for reaction for 10-20 min at the reaction temperature of 200-230 ℃, taking out the solution after the reaction is finished, washing the solution for several times by using DMF (dimethyl formamide), and then putting the solution into a vacuum drying oven at the temperature of 90 ℃ for drying overnight to obtain the Ti/Black-TiO further modified by the MOF material₂NT/Ni/ZIF-9 electrode.

The invention relates to a method for degrading active red 195 by high catalytic activity electrode photoelectrocatalysis, which comprises the following steps:

1) preparation of highly catalytically active electrodes

Preparation of Ti/TiO by anodic oxidation₂NT is reduced and then calcined in nitrogen atmosphere to prepare black Ti/TiO₂NT(Ti/Black-TiO₂NT), and depositing Ni on Ti/Black-TiO by adopting a pulse current deposition method₂On NT to obtain Ti/Black-TiO₂NT/Ni, subsequently microwave synthesized on Ti/Black-TiO₂MOF material ZIF-9 particles are loaded on NT/Ni to obtain Ti/Black-TiO₂NT/Ni/ZIF-9 electrode;

2) photoelectrocatalysis degradation active red 195

The Ti/Black-TiO with high catalytic activity prepared in the step 1)₂The NT/Ni/ZIF-9 electrode is used as an anode, the copper electrode is used as a cathode, a constant-current constant-voltage power supply is adopted, a 500W xenon lamp is adopted as a light source, the temperature is 25 ℃, and the current density is 50mA/m²The degradation liquid is: 10mg/L active Red 195.

As a further improvement of the invention, the Ti/Black-TiO with high catalytic activity is prepared in the step 1)₂The specific steps of the NT/Ni/ZIF-9 electrode are as follows:

the first step,

Selecting pure titanium metal as a titanium sheet, firstly polishing the titanium sheet by three different specifications of 600 meshes, 800 meshes and 1000 meshes of abrasive paper in sequence, then ultrasonically washing the polished titanium sheet in absolute ethyl alcohol, acetone and deionized water for 10min in sequence, then putting the titanium sheet into a mixed solution of ethylene glycol, hydrofluoric acid and secondary distilled water for corrosion treatment for 20min, wherein the surface of the corroded titanium sheet is a white pitted surface, and cleaning the corroded titanium sheet by using deionized water, wherein: hydrofluoric acid, wherein the volume ratio of the ethylene glycol to the secondary distilled water is 2: 6: 10;

step two,

Preparing Ti/TiO by anode oxidation method₂NT, 0.3-0.5 wt% NH and 2-5V% H at room temperature₂In O glycol electrolyte, a Ti sheet is used as an anode, a Cu sheet is used as a cathode, anodic electrooxidation is carried out, the oxidation voltage is 60-100V, the oxidation time is 7-10 h, magnetic stirring is carried out all the time in the oxidation process, a sample is soaked in absolute ethyl alcohol for 2h after the oxidation is finished, the absolute ethyl alcohol is used for carrying out ultrasonic cleaning for 2min, and then the temperature is controlled to be 2-4 mol.L^-1Na₂SO₄To Ti/TiO in solution₂Reduction of NT electrode to obtain Ti⁴⁺Reduction to Ti³⁺Finally, annealing treatment is carried out in the nitrogen atmosphere, the annealing temperature is 500-550 ℃, and heat preservation is carried out for 4 hours, so that the Ti/Black-TiO can be prepared₂An NT electrode;

step three,

Annealing the Ti/Black-TiO annealed in the second step₂The NT electrode is used as a working electrode, the Pt sheet is used as a counter electrode, the saturated calomel electrode is used as a reference electrode, and the electrode is placed in NiSO mixed with 200-400 g/L₄·6H₂O, NiCl of 20-41 g/L₂·6H₂O and 10-32 g/L H₃BO₃In the electroplating solution, the temperature is controlled to be 25 ℃, the stirring speed is 600rpm, and Ni is modified on the nanotube by pulse electrodeposition for 10min to prepare Ti/Black-TiO₂NT/Ni electrode;

step four,

0.1-0.7 g Co (NO)₃)₂And 0.5-0.8 g of benzimidazole is dissolved in 10-40 ml of N, N-dimethylformamide, and the Ti/Black-TiO is added₂Putting NT/Ni into the solution, then putting the solution into a microwave reactor for reaction for 10-20 min at the reaction temperature of 200-230 ℃, taking out the solution after the reaction is finished, washing the solution for several times by using DMF (dimethyl formamide), and then putting the solution into a vacuum drying oven at the temperature of 90 ℃ for drying overnight to obtain the Ti/Black-TiO further modified by the MOF material₂NT/Ni/ZIF-9 electrode.

3. Advantageous effects

Compared with the prior art, the technical scheme provided by the invention has the following remarkable effects:

(1) the high catalytic activity electrode can improve Ti/Black-TiO content by doping metal Ni through pulse electrodeposition₂The conductivity of NT/Ni/ZIF-9, and part of Ni is oxidized into NiO during the electroplating process, and the NiO can be mixed with TiO₂Further forming p-n semiconductor heterojunction, thereby improving Ti/Black-TiO₂NT photocatalytic activity.

(2) The ZIF-9 of the high catalytic activity electrode has high photoelectrocatalysis activity and high specific surface area, and the ZIF-9 modified Ti/Black-TiO is prepared by a microwave synthesis technology₂The NT/Ni electrode is simple to operate, and the prepared ZIF-9 has small (nano-scale) and uniform size, high catalytic activity and micro-scaleThe wave method can also improve the purity, density and uniformity of the ZIF-9 deposition layer and reduce the void ratio, thereby further improving the stability and the photoelectrocatalysis performance of the composite electrode.

(3) The method for photoelectrocatalytic degradation of active red 195 by the high-catalytic-activity electrode has the advantages of simple electrode preparation, simple operation, easy equipment acquisition, simple process flow, low investment cost, good degradation effect of the active red 195, good electrode corrosion resistance, good degradation process stability, higher degradation efficiency than that of a common titanium dioxide nanotube electrode, 99.1-99.9% of the decolorization rate of the active red 195 and 95.8-97.2% of the degradation rate of COD.

Detailed Description

For a further understanding of the present invention, reference will now be made in detail to the following examples.

Example 1

The method for photocatalytically degrading active red 195 by the high-catalytic-activity electrode comprises the following specific steps:

the first step,

Selecting pure titanium metal as a titanium sheet, firstly polishing the titanium sheet by three different specifications of 600 meshes, 800 meshes and 1000 meshes of abrasive paper in sequence, then ultrasonically washing the polished titanium sheet in absolute ethyl alcohol, acetone and deionized water for 10min in sequence, then putting the titanium sheet into a mixed solution of ethylene glycol, hydrofluoric acid and secondary distilled water for corrosion treatment for 20min, wherein the surface of the corroded titanium sheet is a white pitted surface, and cleaning the corroded titanium sheet by using deionized water, wherein: hydrofluoric acid, wherein the volume ratio of the ethylene glycol to the secondary distilled water is 2: 6: 10;

step two,

Preparing Ti/TiO by anode oxidation method₂NT, 0.3 wt% NH and 2V% H at room temperature₂In O glycol electrolyte, a Ti sheet is taken as an anode, a Cu sheet is taken as a cathode, anodic electrooxidation is carried out, the oxidation voltage is 60V, the oxidation time is 7h, magnetic stirring is always carried out in the oxidation process, the sample is soaked in absolute ethyl alcohol for 2h after the oxidation is finished, the absolute ethyl alcohol is used for carrying out ultrasonic cleaning for 2min, and then the solution is subjected to 2 mol.L^-1Na₂SO₄To Ti/TiO in solution₂Reduction of NT electrode firstHandle of Ti⁴⁺Reduction to Ti³⁺Finally annealing treatment is carried out in nitrogen atmosphere, the annealing temperature is 500 ℃, and the heat preservation is carried out for 4 hours, thus obtaining the Ti/Black-TiO₂An NT electrode;

step three,

Annealing the Ti/Black-TiO annealed in the second step₂NT electrode as working electrode, Pt sheet as counter electrode, saturated calomel electrode as reference electrode, placed in NiSO mixed with 200g/L₄·6H₂O, 20g/L NiCl₂·6H₂O and 10g/L of H₃BO₃In the electroplating solution, the temperature is controlled to be 25 ℃, the stirring speed is 600rpm, and Ni is modified on the nanotube by pulse electrodeposition for 10min to prepare Ti/Black-TiO₂NT/Ni electrode;

step four,

0.1g of Co (NO)₃)₂And 0.5g benzimidazole in 10ml N, N-dimethylformamide and adding Ti/Black-TiO₂Putting NT/Ni into the solution, then putting the solution into a microwave reactor for reaction for 10min at the reaction temperature of 200 ℃, taking the solution out after the reaction is finished, washing the solution with DMF for several times, and then putting the solution into a vacuum drying oven at the temperature of 90 ℃ for drying overnight to obtain the Ti/Black-TiO further modified by the MOF material₂NT/Ni/ZIF-9 electrode. It should be noted that: the nano-sized ZIF-9 particles can be obtained by microwave synthesis, and meanwhile, the ZIF-9 particles can be uniformly distributed on Ti/Black-TiO₂On the NT/Ni electrode.

Step five,

The Ti/Black-TiO prepared in the fourth step₂The NT/Ni/ZIF-9 electrode is used as an anode, the copper electrode is used as a cathode, a constant-current constant-voltage power supply is adopted, a 500W xenon lamp is adopted as a light source, the temperature is 25 ℃, and the current density is 50mA/m²The degradation liquid is: 10mg/L active Red 195. After the photoelectric degradation process, the decolorization rate of the active red 195 reaches 99.5 percent, and the degradation rate of COD reaches 96.8 percent.

Example 2

The method for photocatalytically degrading active red 195 by the high-catalytic-activity electrode comprises the following specific steps:

the first step,

Selecting pure titanium metal as a titanium sheet, firstly polishing the titanium sheet by three different specifications of 600 meshes, 800 meshes and 1000 meshes of abrasive paper in sequence, then ultrasonically washing the polished titanium sheet in absolute ethyl alcohol, acetone and deionized water for 10min in sequence, then putting the titanium sheet into a mixed solution of ethylene glycol, hydrofluoric acid and secondary distilled water for corrosion treatment for 20min, wherein the surface of the corroded titanium sheet is a white pitted surface, and cleaning the corroded titanium sheet by using deionized water, wherein: hydrofluoric acid, wherein the volume ratio of the ethylene glycol to the secondary distilled water is 2: 6: 10;

step two,

Preparing Ti/TiO by anode oxidation method₂NT, 0.4 wt% NH and 4V% H at room temperature₂In O glycol electrolyte, a Ti sheet is taken as an anode, a Cu sheet is taken as a cathode, anodic electrooxidation is carried out, the oxidation voltage is 80V, the oxidation time is 8h, magnetic stirring is always carried out in the oxidation process, the sample is soaked in absolute ethyl alcohol for 2h after the oxidation is finished, the absolute ethyl alcohol is used for carrying out ultrasonic cleaning for 2min, and then the solution is subjected to 3 mol.L^-1Na₂SO₄To Ti/TiO in solution₂Reduction of NT electrode to obtain Ti⁴⁺Reduction to Ti³⁺Finally annealing treatment is carried out in nitrogen atmosphere, the annealing temperature is 530 ℃, and heat preservation is carried out for 4 hours, thus obtaining the Ti/Black-TiO₂An NT electrode;

step three,

Annealing the Ti/Black-TiO annealed in the second step₂NT electrode as working electrode, Pt sheet as counter electrode, saturated calomel electrode as reference electrode, placed in NiSO mixed with 300g/L₄·6H₂O, 30g/L NiCl₂·6H₂O and 25g/L of H₃BO₃In the electroplating solution, the temperature is controlled to be 25 ℃, the stirring speed is 600rpm, and Ni is modified on the nanotube by pulse electrodeposition for 10min to prepare Ti/Black-TiO₂NT/Ni electrode;

step four,

0.5g of Co (NO)₃)₂And 0.7g benzimidazole in 30ml N, N-dimethylformamide and adding Ti/Black-TiO₂Putting NT/Ni into the solution, then putting the solution into a microwave reactor for reaction for 15min at the reaction temperature of 210 ℃, taking out the solution after the reaction is finished, washing the solution with DMF for several times, and then putting the solution into a vacuum drying oven at the temperature of 90 ℃ for dryingThen, Ti/Black-TiO modified MOF material is obtained₂NT/Ni/ZIF-9 electrode.

Step five,

The Ti/Black-TiO prepared in the fourth step₂The NT/Ni/ZIF-9 electrode is used as an anode, the copper electrode is used as a cathode, a constant-current constant-voltage power supply is adopted, a 500W xenon lamp is adopted as a light source, the temperature is 25 ℃, and the current density is 50mA/m²The degradation liquid is: 10mg/L active Red 195. After the photoelectric degradation process, the decolorization rate of the active red 195 reaches 99.9 percent, and the degradation rate of COD reaches 97.2 percent.

Example 3

The method for photocatalytically degrading active red 195 by the high-catalytic-activity electrode comprises the following specific steps:

the first step,

Selecting pure titanium metal as a titanium sheet, firstly polishing the titanium sheet by three different specifications of 600 meshes, 800 meshes and 1000 meshes of abrasive paper in sequence, then ultrasonically washing the polished titanium sheet in absolute ethyl alcohol, acetone and deionized water for 10min in sequence, then putting the titanium sheet into a mixed solution of ethylene glycol, hydrofluoric acid and secondary distilled water for corrosion treatment for 20min, wherein the surface of the corroded titanium sheet is a white pitted surface, and cleaning the corroded titanium sheet by using deionized water, wherein: hydrofluoric acid, wherein the volume ratio of the ethylene glycol to the secondary distilled water is 2: 6: 10;

step two,

Preparing Ti/TiO by anode oxidation method₂NT, 0.5 wt% NH and 5V% H at room temperature₂In O glycol electrolyte, a Ti sheet is taken as an anode, a Cu sheet is taken as a cathode, anodic electrooxidation is carried out, the oxidation voltage is 100V, the oxidation time is 10h, magnetic stirring is carried out all the time in the oxidation process, the sample is soaked in absolute ethyl alcohol for 2h after the oxidation is finished, the absolute ethyl alcohol is used for carrying out ultrasonic cleaning for 2min, and then the solution is subjected to 4 mol.L^-1Na₂SO₄To Ti/TiO in solution₂Reduction of NT electrode to obtain Ti⁴⁺Reduction to Ti³⁺Finally annealing treatment is carried out in nitrogen atmosphere, the annealing temperature is 550 ℃, and heat preservation is carried out for 4 hours, thus obtaining the Ti/Black-TiO₂An NT electrode;

step three,

Step two is returnedWell-ignited Ti/Black-TiO₂NT electrode as working electrode, Pt sheet as counter electrode, saturated calomel electrode as reference electrode, placed in NiSO mixed with 400g/L₄·6H₂O, 41g/L NiCl₂·6H₂O and 32g/L of H₃BO₃In the electroplating solution, the temperature is controlled to be 25 ℃, the stirring speed is 600rpm, and Ni is modified on the nanotube by pulse electrodeposition for 10min to prepare Ti/Black-TiO₂NT/Ni electrode;

step four,

0.7g of Co (NO)₃)₂And 0.8g benzimidazole in 40ml N, N-dimethylformamide and adding Ti/Black-TiO₂Putting NT/Ni into the solution, then putting the solution into a microwave reactor for reaction for 20min at the reaction temperature of 230 ℃, taking the solution out after the reaction is finished, washing the solution with DMF for several times, and then putting the solution into a vacuum drying oven at the temperature of 90 ℃ for drying overnight to obtain the Ti/Black-TiO further modified by the MOF material₂NT/Ni/ZIF-9 electrode.

Step five,

The Ti/Black-TiO prepared in the fourth step₂The NT/Ni/ZIF-9 electrode is used as an anode, the copper electrode is used as a cathode, a constant-current constant-voltage power supply is adopted, a 500W xenon lamp is adopted as a light source, the temperature is 25 ℃, and the current density is 50mA/m²The degradation liquid is: 10mg/L active Red 195. After the photoelectric degradation process, the decolorization rate of the active red 195 reaches 99.1 percent, and the degradation rate of COD reaches 95.8 percent.

The high catalytic activity electrode can improve Ti/Black-TiO content by doping metal Ni through pulse electrodeposition₂The conductivity of NT/Ni/ZIF-9, and part of Ni is oxidized into NiO during the electroplating process, and the NiO can be mixed with TiO₂Further forming p-n semiconductor heterojunction, thereby improving Ti/Black-TiO₂NT photocatalytic activity. The ZIF-9 has high photoelectrocatalysis activity and high specific surface area, the ZIF-9 modified Ti/Black-TiO2NT/Ni electrode is prepared by the microwave synthesis technology, the operation is simple, the prepared ZIF-9 has small (nano) particles, uniform size and high catalytic activity, and meanwhile, the microwave method can also improve the purity, density and uniformity of a ZIF-9 deposition layer and reduce the porosity of the ZIF-9 deposition layer, so that the composite photoelectrocatalysis is further improvedExcellent stability and photocatalytic performance.

Modified Ti/Black-TiO by doping in examples 1-3₂The method provided by the invention has the advantages that the efficiency of removing the active red 195 by oxidative degradation is high, the electrode corrosion resistance is good, the stability of the degradation process is good, the degradation efficiency is higher than that of a common titanium dioxide nanotube electrode, the decolorization rate of the active red 195 reaches 99.1-99.9%, the degradation rate of COD reaches 95.8-97.2%, the degradation side reaction is less, the energy consumption is low, and the method belongs to a green chemical part.

The above examples are only intended to illustrate the technical solution of the present invention and are not intended to be limiting. Although the present invention has been described in detail with reference to the preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the present invention.

Claims (4)

1. The high catalytic activity electrode is characterized in that Ti/TiO is prepared by adopting an anodic oxidation method₂NT is reduced and then calcined in nitrogen atmosphere to prepare black Ti/TiO₂NT(Ti/Black-TiO₂NT), and depositing Ni on Ti/Black-TiO by adopting a pulse current deposition method₂On NT to obtain Ti/Black-TiO₂NT/Ni, subsequently microwave synthesized on Ti/Black-TiO₂MOF material ZIF-9 particles are loaded on NT/Ni to obtain Ti/Black-TiO₂NT/Ni/ZIF-9 electrode.

2. The electrode with high catalytic activity according to claim 1, characterized in that the specific steps of its preparation are:

the first step,

Selecting pure titanium metal as a titanium sheet, firstly polishing the titanium sheet by three different specifications of 600 meshes, 800 meshes and 1000 meshes of abrasive paper in sequence, then ultrasonically washing the polished titanium sheet in absolute ethyl alcohol, acetone and deionized water for 10min in sequence, then putting the titanium sheet into a mixed solution of ethylene glycol, hydrofluoric acid and secondary distilled water for corrosion treatment for 20min, wherein the surface of the corroded titanium sheet is a white pitted surface, and cleaning the corroded titanium sheet by using deionized water, wherein: hydrofluoric acid, wherein the volume ratio of the ethylene glycol to the secondary distilled water is 2: 6: 10;

step two,

Preparing Ti/TiO by anode oxidation method₂NT, 0.3-0.5 wt% NH and 2-5V% H at room temperature₂In O glycol electrolyte, a Ti sheet is used as an anode, a Cu sheet is used as a cathode, anodic electrooxidation is carried out, the oxidation voltage is 60-100V, the oxidation time is 7-10 h, magnetic stirring is carried out all the time in the oxidation process, a sample is soaked in absolute ethyl alcohol for 2h after the oxidation is finished, the absolute ethyl alcohol is used for carrying out ultrasonic cleaning for 2min, and then the temperature is controlled to be 2-4 mol.L^-1Na₂SO₄To Ti/TiO in solution₂Reduction of NT electrode to obtain Ti⁴⁺Reduction to Ti³⁺Finally, annealing treatment is carried out in the nitrogen atmosphere, the annealing temperature is 500-550 ℃, and heat preservation is carried out for 4 hours, so that the Ti/Black-TiO can be prepared₂An NT electrode;

step three,

Annealing the Ti/Black-TiO annealed in the second step₂The NT electrode is used as a working electrode, the Pt sheet is used as a counter electrode, the saturated calomel electrode is used as a reference electrode, and the electrode is placed in NiSO mixed with 200-400 g/L₄·6H₂O, NiCl of 20-41 g/L₂·6H₂O and 10-32 g/L H₃BO₃In the electroplating solution, the temperature is controlled to be 25 ℃, the stirring speed is 600rpm, and Ni is modified on the nanotube by pulse electrodeposition for 10min to prepare Ti/Black-TiO₂NT/Ni electrode;

step four,

0.1-0.7 g Co (NO)₃)₂And 0.5-0.8 g of benzimidazole is dissolved in 10-40 ml of N, N-dimethylformamide, and the Ti/Black-TiO is added₂Putting NT/Ni into the solution, then putting the solution into a microwave reactor for reaction for 10-20 min at the reaction temperature of 200-230 ℃, taking out the solution after the reaction is finished, washing the solution for several times by using DMF (dimethyl formamide), and then putting the solution into a vacuum drying oven at the temperature of 90 ℃ for drying overnight to obtain the Ti/Black-TiO further modified by the MOF material₂NT/Ni/ZIF-9 electrode.

3. A method for degrading active red 195 by high catalytic activity electrode photoelectrocatalysis is characterized by comprising the following steps:

1) preparation of highly catalytically active electrodes

Preparation of Ti/TiO by anodic oxidation₂NT is reduced and then calcined in nitrogen atmosphere to prepare black Ti/TiO₂NT(Ti/Black-TiO₂NT), and depositing Ni on Ti/Black-TiO by adopting a pulse current deposition method₂On NT to obtain Ti/Black-TiO₂NT/Ni, subsequently microwave synthesized on Ti/Black-TiO₂MOF material ZIF-9 particles are loaded on NT/Ni to obtain Ti/Black-TiO₂NT/Ni/ZIF-9 electrode;

2) photoelectrocatalysis degradation active red 195

The Ti/Black-TiO with high catalytic activity prepared in the step 1)₂The NT/Ni/ZIF-9 electrode is used as an anode, the copper electrode is used as a cathode, a constant-current constant-voltage power supply is adopted, a 500W xenon lamp is adopted as a light source, the temperature is 25 ℃, and the current density is 50mA/m²The degradation liquid is: 10mg/L active Red 195.

4. The method for photoelectrocatalytic degradation of active red 195 with a high catalytic activity electrode as claimed in claim 3, wherein the high catalytic activity Ti/Black-TiO prepared in step 1) is₂The specific steps of the NT/Ni/ZIF-9 electrode are as follows:

the first step,

Selecting pure titanium metal as a titanium sheet, firstly polishing the titanium sheet by three different specifications of 600 meshes, 800 meshes and 1000 meshes of abrasive paper in sequence, then ultrasonically washing the polished titanium sheet in absolute ethyl alcohol, acetone and deionized water for 10min in sequence, then putting the titanium sheet into a mixed solution of ethylene glycol, hydrofluoric acid and secondary distilled water for corrosion treatment for 20min, wherein the surface of the corroded titanium sheet is a white pitted surface, and cleaning the corroded titanium sheet by using deionized water, wherein: hydrofluoric acid, wherein the volume ratio of the ethylene glycol to the secondary distilled water is 2: 6: 10;

step two,

Preparing Ti/TiO by anode oxidation method₂NT, mass at room temperatureThe fraction of NH is 0.3-0.5 wt% and H is 2-5V%₂In O glycol electrolyte, a Ti sheet is used as an anode, a Cu sheet is used as a cathode, anodic electrooxidation is carried out, the oxidation voltage is 60-100V, the oxidation time is 7-10 h, magnetic stirring is carried out all the time in the oxidation process, a sample is soaked in absolute ethyl alcohol for 2h after the oxidation is finished, the absolute ethyl alcohol is used for carrying out ultrasonic cleaning for 2min, and then the temperature is controlled to be 2-4 mol.L^-1Na₂SO₄To Ti/TiO in solution₂Reduction of NT electrode to obtain Ti⁴⁺Reduction to Ti³⁺Finally, annealing treatment is carried out in the nitrogen atmosphere, the annealing temperature is 500-550 ℃, and heat preservation is carried out for 4 hours, so that the Ti/Black-TiO can be prepared₂An NT electrode;

step three,

Annealing the Ti/Black-TiO annealed in the second step₂The NT electrode is used as a working electrode, the Pt sheet is used as a counter electrode, the saturated calomel electrode is used as a reference electrode, and the electrode is placed in NiSO mixed with 200-400 g/L₄·6H₂O, NiCl of 20-41 g/L₂·6H₂O and 10-32 g/L H₃BO₃In the electroplating solution, the temperature is controlled to be 25 ℃, the stirring speed is 600rpm, and Ni is modified on the nanotube by pulse electrodeposition for 10min to prepare Ti/Black-TiO₂NT/Ni electrode;

step four,

0.1-0.7 g Co (NO)₃)₂And 0.5-0.8 g of benzimidazole is dissolved in 10-40 ml of N, N-dimethylformamide, and the Ti/Black-TiO is added₂Putting NT/Ni into the solution, then putting the solution into a microwave reactor for reaction for 10-20 min at the reaction temperature of 200-230 ℃, taking out the solution after the reaction is finished, washing the solution for several times by using DMF (dimethyl formamide), and then putting the solution into a vacuum drying oven at the temperature of 90 ℃ for drying overnight to obtain the Ti/Black-TiO further modified by the MOF material₂NT/Ni/ZIF-9 electrode.