阅读说明：本技术 采用纳米掺硼金刚石膜电极的电化学分析装置及其应用 (Electrochemical analysis device adopting nano boron-doped diamond membrane electrode and application thereof ) 是由 刘建波 尚永辉 张萍 于 2019-10-18 设计创作，主要内容包括：本发明提供了采用纳米掺硼金刚石膜电极的电化学分析装置,包括底座、电解池和电解池盖；底座顶部设有一体结构的电解池,底座还设有电机,电机的输出轴伸至电解池内底部并连有搅拌叶片；电解池的侧壁装设有参比电极；电解池盖上对应装设有辅助电极和工作电极；工作电极为纳米掺硼金刚石膜电极；电解池盖还设有通气口；电解池下部还设有电解池排液口。本发明的装置结构简单,使用方便,有效避免了三电极体系搭建过程的繁琐,同时克服了由于搭建时三电极相对距离不固定造成的重现性差的问题；本发明还保护该电化学分析装置在污水处理时水体化学需氧量检测中的应用,本发明的电化学分析装置测量量程较宽,可达到7324.5mg/L,具有较高的现实意义。(The invention provides an electrochemical analysis device adopting a nano boron-doped diamond membrane electrode, which comprises a base, an electrolytic cell and an electrolytic cell cover, wherein the base is provided with a plurality of grooves; the top of the base is provided with an electrolytic cell with an integrated structure, the base is also provided with a motor, and an output shaft of the motor extends to the bottom in the electrolytic cell and is connected with a stirring blade; the side wall of the electrolytic cell is provided with a reference electrode; the electrolytic cell cover is correspondingly provided with an auxiliary electrode and a working electrode; the working electrode is a nano boron-doped diamond membrane electrode; the electrolytic cell cover is also provided with an air vent; the lower part of the electrolytic cell is also provided with an electrolytic cell liquid outlet. The device disclosed by the invention is simple in structure and convenient to use, effectively avoids the complexity of the construction process of a three-electrode system, and simultaneously solves the problem of poor reproducibility caused by unfixed relative distance of three electrodes during construction; the invention also protects the application of the electrochemical analysis device in the detection of the chemical oxygen demand of the water body during sewage treatment, and the electrochemical analysis device has wider measurement range which can reach 7324.5mg/L and has higher practical significance.)

1. The electrochemical analysis device adopting the nano boron-doped diamond membrane electrode is characterized by comprising a base (1), an electrolytic cell (2) and an electrolytic cell cover (3) which can be hermetically connected with the electrolytic cell (2);

The electrolytic cell (2) of an integrated structure is arranged at the top of the base (1), the base (1) is of a hollow structure, a motor (4) is arranged in the base (1), an output shaft of the motor (4) penetrates through the base (1) and extends to the inner bottom of the electrolytic cell (2), and the top of the output shaft is connected with a stirring blade;

a reference electrode mounting hole is formed in the side wall of the electrolytic cell (2), a reference electrode (5) is arranged in the reference electrode mounting hole, and the front end of the reference electrode (5) is positioned in the electrolytic cell (2);

an auxiliary electrode mounting hole and a working electrode mounting hole penetrate through the electrolytic cell cover (3), an auxiliary electrode (6) is arranged in the auxiliary electrode mounting hole, a working electrode (7) is arranged in the working electrode mounting hole, and the front ends of the auxiliary electrode (6) and the working electrode (7) are both positioned in the electrolytic cell (2);

the working electrode (7) is a nano boron-doped diamond membrane electrode;

The electrolytic cell cover (3) is also provided with an air vent (8);

the lower part of the side wall of the electrolytic cell (2) is also communicated with an electrolytic cell liquid outlet (9), and a sealing plug is arranged on the electrolytic cell liquid outlet (9).

2. the electrochemical analysis device adopting the nano boron-doped diamond membrane electrode as set forth in claim 1, further comprising an electrochemical analyzer and a computer equipped with workstation software of the electrochemical analyzer, wherein the computer is electrically connected with the electrochemical analyzer, and the electrochemical analyzer is electrically connected with the reference electrode (5), the auxiliary electrode (6) and the working electrode (7) in a one-to-one correspondence manner through leads.

3. The electrochemical analysis device adopting the nano boron-doped diamond membrane electrode as set forth in claim 1, wherein a jacket (11) capable of surrounding the electrolytic cell (2) is detachably connected to the base (1), a heating wire and a temperature sensor are disposed in the jacket (11), a controller is disposed outside the jacket (11), the controller can be electrically connected with an external power supply, and the controller is electrically connected with both the heating wire and the temperature sensor.

4. The electrochemical analysis device adopting the nano boron-doped diamond membrane electrode according to claim 1, wherein the sealing plug is a silica gel sealing plug.

5. The electrochemical analysis device adopting the nano boron-doped diamond membrane electrode as set forth in claim 1, wherein the electrolytic cell (2) is connected with the electrolytic cell cover (3) by a screw thread, and the electrolytic cell (2) is made of transparent organic glass material.

6. the electrochemical analysis device adopting the nano boron-doped diamond membrane electrode as set forth in claim 1, wherein a three-way piston for ventilation is further provided on the vent (8).

7. the electrochemical analysis device adopting the nano boron-doped diamond membrane electrode as set forth in claim 1, wherein the reference electrode (5) is a saturated calomel electrode or an Ag/AgCl electrode, and the auxiliary electrode (6) is a platinum electrode.

8. the electrochemical analysis device adopting the nano boron-doped diamond membrane electrode as set forth in claim 1, wherein an electrolyte inlet (10) is further provided on an upper portion of a sidewall of the electrolytic cell (2), and a sealing cover is detachably connected to the electrolyte inlet (10).

9. The use of the electrochemical analyzer with the nano boron-doped diamond membrane electrode according to any one of claims 1 to 8, wherein the electrochemical analyzer is used in chemical oxygen demand measurement in sewage treatment.

Technical Field

The invention relates to the technical field of analytical chemistry, in particular to an electrochemical analysis device adopting a nanometer boron-doped diamond membrane electrode and application thereof.

Background

with social development and technological progress, people's environmental awareness is gradually strengthened, and detection and control of water pollution are more and more paid attention. At present, the major water body pollution in China is mainly organic pollution, and Chemical Oxygen Demand (COD) is an important parameter for evaluating the organic pollution degree of the water body. COD is the amount of an oxidizing agent consumed in treating a water sample with a specific strong oxidizing agent such as potassium dichromate or potassium permanganate under strong acid and heating conditions, and is expressed in terms of the equivalent oxygen concentration (mg/L). The standard method for measuring the COD of the water body is a potassium dichromate titration method, the method is accurate in measurement and good in reproducibility, but the operation process is too complicated, reflux titration is required in the test, and the consumed time is long. In recent years, new methods such as ultraviolet absorption spectroscopy, photocatalytic methods, photoelectrocatalysis methods, and electrochemical methods have appeared. The ultraviolet absorption spectrometry is to measure organic matters according to different absorptions of the organic matters in water under ultraviolet light with specific wavelength, but the ultraviolet absorption difference of different organic matters is large, so that the measurement of complex wastewater is easy to deviate; the photocatalytic method and the photoelectrocatalysis method oxidize reducing substances in wastewater by using cavities or free radicals during ultraviolet irradiation, and obtain corresponding COD by detecting electric quantity or current value, but the method is easy to generate deviation on wastewater with low light transmittance such as high turbidity, high chroma and the like. Relatively speaking, the COD is measured by the electrochemical method by applying a constant potential to a three-electrode system including a working electrode, electrolyzing water to generate hydroxyl radicals, wherein the hydroxyl radicals are used as a strong oxidant, organic matters in water can be quickly oxidized to generate an electric signal, and the concentration of the COD in the water is measured by utilizing the size of the generated response signal.

At present, most of electrodes used for testing COD by using electrochemical method are AgO/CuO composite electrodes or PbO₂The electrode, however, AgO/CuO composite electrode has not high oxidation capacity, PbO₂The electrode is not corrosion-resistant, and the heavy metal ions are eluted in an acidic or alkaline medium, so that the detection signal is interfered, and therefore, the design of an electrochemical analysis device with a proper electrode material is necessary.

Disclosure of Invention

the invention aims to solve the defects of the technology and provides an electrochemical analysis device adopting the nano boron-doped diamond membrane electrode, the device is reasonable in design and simple to operate, the nano boron-doped diamond membrane electrode is used as a working electrode, strong oxidant hydroxyl radicals with high oxidation-reduction potential are generated on the surface of the working electrode in the detection process, organic pollutants in water can be completely oxidized, the nano boron-doped diamond membrane electrode is corrosion-resistant and pollution-resistant, harmful substances cannot be generated in the detection process and after the detection is finished, and the device is safe and environment-friendly.

in order to achieve the purpose, the invention adopts the technical scheme that:

The electrochemical analysis device adopting the nanometer boron-doped diamond membrane electrode comprises a base, an electrolytic cell and an electrolytic cell cover which can be hermetically connected with the electrolytic cell;

the top of the base is provided with an electrolytic cell with an integrated structure, the base is of a hollow structure and is internally provided with a motor, an output shaft of the motor penetrates through the base and extends to the inner bottom of the electrolytic cell, and the top of the output shaft is connected with a stirring blade;

a reference electrode mounting hole is formed in the side wall of the electrolytic cell, a reference electrode is arranged in the reference electrode mounting hole, and the front end of the reference electrode is positioned in the electrolytic cell;

An auxiliary electrode mounting hole and a working electrode mounting hole are arranged on the electrolytic cell cover in a penetrating manner, an auxiliary electrode is arranged in the auxiliary electrode mounting hole, a working electrode is arranged in the working electrode mounting hole, and the front ends of the auxiliary electrode and the working electrode are both positioned in the electrolytic cell;

The working electrode is a nano boron-doped diamond membrane electrode;

The electrolytic cell cover is also provided with an air vent;

The lower part of the side wall of the electrolytic cell is also communicated with a liquid outlet of the electrolytic cell, and a sealing plug is arranged on the liquid outlet of the electrolytic cell.

preferably, the electrochemical analyzer further comprises an electrochemical analyzer and a computer provided with workstation software of the electrochemical analyzer, the computer is electrically connected with the electrochemical analyzer, and the electrochemical analyzer is electrically connected with the reference electrode, the auxiliary electrode and the working electrode in a one-to-one correspondence manner through leads.

Preferably, the base is detachably connected with a jacket capable of surrounding the electrolytic cell, the jacket is internally provided with a heating wire and a temperature sensor, the jacket is externally provided with a controller, the controller can be electrically connected with an external power supply, and the controller is electrically connected with the heating wire and the temperature sensor.

Preferably, the sealing plug is a silicone sealing plug.

preferably, the electrolytic cell is in threaded connection with the electrolytic cell cover, and the electrolytic cell is made of transparent organic glass.

Preferably, the vent is further provided with a three-way piston for ventilation.

Preferably, the reference electrode is a saturated calomel electrode or an Ag/AgCl electrode, and the auxiliary electrode is a platinum electrode.

preferably, the upper part of the side wall of the electrolytic cell is also provided with an electrolyte adding port, and the electrolyte adding port is detachably connected with a sealing cover.

The invention also protects the application of the electrochemical analysis device in COD detection in sewage treatment.

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

1. according to the electrochemical analysis device, the reference electrode is arranged on the inner wall of the electrolytic cell, and the auxiliary electrode and the working electrode are arranged on the electrolytic cell cover, so that the position relation among the three electrodes and the relative distance among the three electrodes are defined, and the problem of poor reproducibility caused by the change of the relative distance in the process of building the device is effectively avoided;

2. According to the invention, through the arrangement of the motor and the stirring blade, the liquid to be detected can be uniformly stirred without additionally using a stirrer, the use is convenient, and the stirring blade is wrapped with the anti-corrosion coating, so that the influence of the stirring blade on the liquid to be detected is effectively avoided, and the service life of the stirring blade is ensured;

3. According to the invention, through the arrangement of the liquid outlet of the electrolytic cell and the electrolyte inlet, the replacement and the supplement of the electrolyte during the detection are facilitated, the electrolyte is discharged after the detection is finished, the electrolytic cell can be cleaned under the condition that the electrolytic cell and the electrolytic cell cover are not disassembled, and the working electrode is cleaned by replacing the sulfuric acid solution;

4. The electrochemical analysis device adopts the nanometer boron-doped diamond membrane electrode as the working electrode, and in the detection process, a certain voltage is applied between the boron-doped diamond membrane electrode and the platinum electrode, so that strong oxidant hydroxyl free radicals with high oxidation-reduction potential are generated on the surface of the boron-doped diamond membrane electrode, the oxidation-reduction potential (2.8V) of the boron-doped diamond membrane electrode is far higher than that of dichromate ions (1.4V), organic pollutants in water can be completely oxidized, the detection accuracy is high, the measurement range is wider, and the measurement range can reach 7324.5 mg/L; and other harmful substances are not generated in the detection process, so that the method is safe and environment-friendly;

5. The invention adopts a boron-doped diamond film electrode as a working electrode, wherein sp is formed between carbon atoms in diamond³the hybrid mode is combined, the structure is very stable, the chemical stability is high, and the activation can be carried out under a higher anode potential to remove the pollution on the surface; meanwhile, the boron-doped diamond membrane electrode has the advantages of pollution resistance, corrosion resistance and the like, and is long in service life.

drawings

FIG. 1 is a schematic view showing the construction of an electrochemical analysis apparatus of the present invention without a jacket;

FIG. 2 is a schematic view showing the structure of an electrochemical analysis apparatus according to the present invention in the case where the apparatus has a jacket.

In the figure: 1. a base; 2. an electrolytic cell; 3. an electrolytic cell cover; 4. a motor; 5. a reference electrode; 6. an auxiliary electrode; 7. a working electrode; 8. a vent; 9. a liquid outlet of the electrolytic cell; 10. an electrolyte inlet; 11. and a jacket.

Detailed Description

The present invention will be described in detail below with reference to specific embodiments. The scope of the invention is not limited to the specific embodiments.