Electric cleaning method for keeping stable electrochemical activity of surface of working electrode and application of electric cleaning method

Abstract

The invention belongs to the technical field of chloride ion detection, particularly relates to an electric cleaning method for keeping the electrochemical activity of the surface of a working electrode stable and application thereof, and aims to solve the problems that electrolyte needs to be added again after cleaning, the whole process is tedious, a large amount of electrolyte needs to be consumed, the detection efficiency and speed are reduced, and the detection cost is increased. In order to solve the problem that when the available chlorine concentration is detected, the pH value of the surface of a working electrode is changed by changing the reaction potential, so that inorganic dirt, loaded acid radical ions and metal ions are removed from the surface of the working electrode, and the experimental error is increased due to long-time exposure of a to-be-detected liquid in the air during detection of the available chlorine concentration. The electrochemical activity of the surface of the working electrode is kept stable for a long time in the determination process, so that the stability and accuracy of detection data are ensured, the surface of the working electrode can be cleaned without dismounting the reference electrode module, the tetrafluoroethylene gasket and the working electrode module, and the operation is convenient and quick.

Description

Technical Field

[0001] The invention belongs to the field of chloride ion detection, and in particular to an electric cleaning method for maintaining stable electrochemical activity on the surface of a working electrode and an application thereof. Background Art

[0002] Hypochlorous acid disinfectant has strong bactericidal ability and good safety, becoming the best choice to replace traditional disinfectants such as 84 liquid, alcohol, peracetic acid, hydrogen peroxide, etc. When the concentration of hypochlorous acid disinfectant is detected online, the effective chlorine concentration of hypochlorous acid is evaluated by measuring the redox potential (ORP) of the solution. The redox potential value changes with the change of the pH value of the solution, resulting in uncertainty in the online detection value. In addition, when detecting the effective chlorine concentration, the liquid to be tested is added to the reaction cup for detection. The long-term exposure of the liquid to be tested to the air will increase the experimental error. In order to reduce the resistance R value of the solution to be tested, electrolytes need to be added to the reaction cup to reduce the resistance. However, during continuous detection, in order to ensure the detection accuracy, the working electrode and the reaction cup need to be cleaned at regular intervals, but electrolytes need to be added again after cleaning. The whole process is cumbersome and consumes a large amount of electrolytes, which reduces the efficiency and speed of detection and increases the detection cost. Summary of the invention

[0003] 1. Technical issues to be resolved The present invention provides an electro-cleaning method and application thereof for maintaining stable electrochemical activity on the surface of a working electrode in order to solve the following problems: 1. When testing the effective chlorine concentration, add the test solution into the reaction cup for testing. If the test solution is exposed to the air for a long time, the experimental error will increase. 2. During continuous detection, the working electrode and reaction cup need to be cleaned at regular intervals to ensure detection accuracy. However, electrolyte needs to be added again after cleaning. The whole process is cumbersome and consumes a large amount of electrolyte, which reduces the efficiency and speed of detection and increases the detection cost.

[0004] (II) Technical content To achieve the above object, the present invention provides the following technical solutions: An electro-cleaning method for maintaining stable electrochemical activity on the surface of a working electrode and its application, specifically comprising the following steps: S1: Apply a reaction potential of -200mv VS Ag / AgCl to the working electrode, hypochlorous acid disinfectant water undergoes a reduction reaction with the working electrode, the reaction is maintained for 1s, and all peak current data within 1s are collected; S2: After the peak current data collection is completed, the reaction potential is increased from -200mv VS Ag / AgCl to 1300mv VS Ag / AgCl. At this time, water oxidation reaction occurs on the electrode surface of the working electrode, and the aqueous solution on the surface of the working electrode becomes strongly acidic. The electrode surface of the working electrode is acid-washed for 2s. S3: After the completion of S2, the reaction potential is reduced from 1300 mv VS Ag / AgCl to 0 mv VS Ag / AgCl, and the maintenance time is 2 s; S4: After the completion of S3, the reaction potential is further reduced from 0mv VS Ag / AgCl to -900mv VS Ag / AgCl. At this time, a water reduction reaction occurs on the electrode surface of the working electrode, and the aqueous solution on the surface of the working electrode becomes strongly alkaline. The electrode surface of the working electrode is washed with alkali for 2s. S5: After the completion of S4, the reaction potential is restored from -900 mv VS Ag / AgCl to 0 mv VS Ag / AgCl for 3 seconds; and then S1-S5 are repeated to start the next cycle.

[0005] Furthermore, the electrode surface of the working electrode is made of any one of gold, platinum, titanium and glassy carbon.

[0006] Furthermore, an electro-cleaning method for maintaining stable electrochemical activity on the surface of a working electrode is used to clean a working electrode of a thin-layer channel electrochemical sensor, wherein the thin-layer channel electrochemical sensor comprises a host, a docking seat, a reference electrode module and a working electrode module, wherein the docking seat is installed inside the host, and the working electrode module is installed on the docking seat; A tetrafluoroethylene gasket is placed on the upper surface of the working electrode module, the reference electrode module is installed on the working electrode module, and the bottom of the reference electrode module is in contact with the tetrafluoroethylene gasket, and the tetrafluoroethylene gasket is provided with a thin layer channel; The reference electrode module is provided with a liquid inlet cavity, the bottom of the reference electrode module is provided with a reference electrode hole connected to the liquid inlet cavity, the top of the reference electrode module is provided with a reference electrode connected to the liquid inlet cavity, the reference electrode, a liquid inlet structure connected to the liquid inlet cavity is provided on one side of the reference electrode module, the reference electrode module is also provided with a liquid drainage groove, and a liquid drainage structure is provided on the top of the liquid drainage groove; The working electrode is installed in the working electrode module, and the working electrode module is also installed with a counter electrode, and the working electrode and the counter electrode are both electrically connected to the host; The liquid inlet cavity, the thin layer channel and the liquid discharge groove are combined into a reaction channel, the reference electrode is connected to the reaction channel through the reference electrode hole, and the upper surfaces of the reference electrode, the working electrode and the counter electrode are connected to the reaction channel; The docking seat is provided with a positioning structure, which is used to enhance the stability between the reference electrode module, the tetrafluoroethylene gasket and the working electrode module.

[0007] Furthermore, a plurality of positioning rods are installed at the bottom of the reference electrode module, a positioning socket corresponding to the plurality of positioning rods is provided on the upper surface of the working electrode module, a positioning through-hole corresponding to the plurality of positioning rods is provided on the tetrafluoroethylene gasket, and the free ends of the plurality of positioning rods pass through the positioning through-holes and are plugged into the positioning sockets; The thickness of the tetrafluoroethylene gasket is 25 μm; The upper surface of the working electrode is circular and has a diameter of 1 mm; The working electrode is located directly below the reference electrode hole.

[0008] Furthermore, a first pair of interfaces communicating with the liquid inlet cavity is provided on one side of the reference electrode module, and a first sealing ring is attached to the inner wall of the first pair of interfaces; The liquid inlet structure comprises a first connecting screw rod, one end of which is threadedly connected to the first docking port and the end thereof is in contact with the first sealing ring, an introduction tube is fixedly embedded inside the first connecting screw rod, one end of which passes through the first connecting screw rod and is in communication with the liquid inlet cavity; The other end of the first connecting screw rod is fixedly connected to the first screwing part, and a second sealing ring is embedded on the side of the first screwing part close to the reference electrode module. The other end of the introduction tube passes through the first connecting screw rod and the first screwing part, and the end is connected to the sample outlet of the hypochlorous acid disinfectant water production line through a pulsation-free pump, and the pulsation-free pump is connected to the main machine for signal transmission.

[0009] Further, the drainage groove is provided with a second docking port, the inner wall of the second docking port is provided with a third sealing ring, the drainage structure includes a second connecting screw rod, one end of the second connecting screw rod is threadedly connected to the second docking port and the end thereof is abutted against the third sealing ring, a guide tube is fixedly embedded inside the second connecting screw rod, one end of the guide tube passes through the second connecting screw rod and is connected to the drainage groove; The other end of the second connecting screw rod is fixedly connected to the second screwing part, and a fourth sealing ring is embedded in the side of the second screwing part close to the reference electrode module. The other end of the outlet pipe passes through the second screwing part and extends outside. As the pulsation-free pump continuously delivers hypochlorous acid disinfectant water into the liquid inlet cavity, the hypochlorous acid disinfectant water in the thin layer channel is discharged through the outlet pipe.

[0010] Further, the positioning structure includes a balance plate and a bolt pressure head, two spring grooves are provided on one side of the inner wall of the docking seat, two sliders are provided on one side of the balance plate, the sliders are slidably connected in the spring grooves, springs are provided in the two spring grooves, and one end of the spring is fixedly connected to the slider, and the other end is fixedly connected to the top of the inner cavity of the spring groove; The top of the docking seat is threadedly connected with a bolt pressure head, and the bottom ends of the two bolt pressure heads are threadedly penetrated through the docking seat and abut against the upper surface of the balance plate; The balancing plate is provided with two avoidance holes, the top of the reference electrode is located in one of the avoidance holes, and the second screwing portion is located in the other avoidance hole.

[0011] Furthermore, in S1, a reaction potential of -200mv VS Ag / AgCl is applied to the working electrode, and the hypochlorous acid disinfectant water undergoes a reduction reaction with the working electrode, namely: 2HClO+H + +e=H2O+2HCl+1 / 2O2, the reaction duration is 1s, and all peak current data within 1s are collected.

[0012] Furthermore, after the peak current data collection is completed, the reaction potential is increased from -200mv VS Ag / AgCl to 1300mv VS Ag / AgCl and maintained for 2s. At this time, water oxidation reaction occurs on the electrode surface of the working electrode, that is, H2O=2H + +2e+1 / 2O2, at this time, the aqueous solution on the surface of the working electrode is strongly acidic, and the surface of the working electrode is acid-washed to remove inorganic dirt and negatively charged acid radical ions attached to the surface of the working electrode; After 2s, the reaction potential is reduced from 1300mv VS Ag / AgCl to 0mv VS Ag / AgCl and maintained for 2s. At this time, as the hypochlorous acid disinfectant in the liquid inlet chamber continuously flows into the thin layer channel, the strongly acidic aqueous solution on the surface of the working electrode is discharged along the drainage groove and the outlet pipe along with the hypochlorous acid disinfectant.

[0013] Further, after the completion of S3, the reaction potential is reduced from 0mv VS Ag / AgCl to -900mv VS Ag / AgCl, and the maintenance time is 2s. At this time, a water reduction reaction occurs on the electrode surface of the working electrode, that is, 2H2O+2e=H2+2OH - At this time, the aqueous solution on the surface of the working electrode becomes strongly alkaline, and the electrode surface of the working electrode is washed with alkali to remove organic dirt on the surface of the working electrode and metal ions attached to the surface of the working electrode; After 2s, the reaction potential is restored from -900mv VS Ag / AgCl to 0mv VS Ag / AgCl, and the maintenance time is 3s. At this time, as the hypochlorous acid disinfectant water in the liquid inlet chamber continuously flows into the thin layer channel, the strongly alkaline aqueous solution on the surface of the working electrode is discharged along the drainage groove and the outlet pipe along with the hypochlorous acid disinfectant water.

[0014] (III) Beneficial effects Compared with the prior art, the present invention has the following beneficial effects: 1. In the present invention, by setting the thickness of the tetrafluoroethylene gasket to 25 μm, the distance between the reference electrode hole and the working electrode is precisely controlled at 25 μm, and the thickness of the thin layer channel is also precisely controlled at 25 μm, thereby effectively reducing the solution measurement resistance R value. The upper surface of the working electrode is circular and has a diameter of 1 mm, which can effectively reduce the measurement current density I, thereby reducing the IR value of the measurement system, thereby achieving the purpose of accurately measuring the effective chlorine concentration without adding electrolyte.

[0015] 2. In the present invention, the pH value of the working electrode surface is changed by changing the reaction potential, thereby removing organic and inorganic dirt, loaded acid ions and metal ions from the working electrode surface. By continuously carrying out the detection and cleaning cycle, it is ensured that the electrochemical activity of the working electrode surface remains stable for a long time during the measurement process, thereby ensuring the stability and accuracy of the detection data. Therefore, the surface of the working electrode can be cleaned without removing the reference electrode module, the tetrafluoroethylene gasket and the working electrode module, which is convenient and quick.

[0016] 3. In the present invention, the balance plate is driven to move by rotating the bolt pressure head, which can ensure that when the balance plate moves to any position, under the action of the bolt pressure head and the spring, the balance plate will not reset or automatically move down, so that the staff can adjust the reference electrode module, the tetrafluoroethylene gasket and the working electrode module midway.

[0017] 4. In the present invention, the bolt pressure head is rotated clockwise, and the bolt pressure head presses the balance plate downward. The balance plate slides downward along the spring groove through the slider so that the bottom of the balance plate contacts the top of the reference electrode module, and the reference electrode module is squeezed, so that the reference electrode module, the tetrafluoroethylene gasket and the working electrode module are closely fitted, thereby improving the air tightness of the reaction channel.

[0018] 5. In the present invention, as the hypochlorous acid disinfectant in the liquid inlet cavity continuously flows into the thin layer channel, inorganic dirt, loaded acid ions and metal ions on the surface of the working electrode are discharged along the drainage groove and the outlet pipe along with the hypochlorous acid disinfectant. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A three-dimensional schematic diagram of the present invention as a whole; Figure 2 A schematic diagram of the interior of the host in the present invention; Figure 3 It is a schematic diagram of the docking seat, reference electrode module, tetrafluoroethylene gasket and working electrode module in the present invention; Figure 4 It is a cross-sectional schematic diagram of the reference electrode module, the tetrafluoroethylene gasket and the working electrode module in the present invention; Figure 5 Schematic diagram of the reaction channel in the present invention; Figure 6 It is an exploded schematic diagram of the reference electrode module, the tetrafluoroethylene gasket and the working electrode module in the present invention; Figure 7 is a cross-sectional schematic diagram of a reference electrode module in the present invention; Figure 8 for Figure 7 A local enlarged schematic diagram of the middle A; Fig. 9 It is a schematic diagram of the liquid inlet structure in the present invention; Fig.10 for Figure 7 A partial enlarged schematic diagram of point B in the middle; Fig.11 It is a schematic diagram of the liquid outlet structure in the present invention; Fig.12 is a schematic diagram of the positioning structure in the present invention; Fig.13 is a schematic diagram of a balance board in the present invention; Fig.14 It is a schematic diagram of the process of applying reaction potential and duration to the working electrode in the present invention; Fig.15 It is the relationship diagram between the effective chlorine concentration and the peak current in the present invention.

[0020] In the figure: 1. working electrode; 2. docking seat; 3. reference electrode module; 4. working electrode module; 5. tetrafluoroethylene gasket; 6. thin layer channel; 7. liquid inlet cavity; 8. reference electrode hole; 9. reference electrode; 10. drainage channel; 11. counter electrode; 12. positioning rod; 13. positioning socket; 14. positioning perforation; 15. first pair of interfaces; 16. first sealing ring; 17. first connecting screw rod; 18. introduction tube; 19. first screwing part; 20. second sealing ring; 21. second pair of interfaces; 22. third sealing ring; 23. second connecting screw rod; 24. outlet tube; 25. second screwing part; 26. fourth sealing ring; 27. balance plate; 28. bolt pressure head; 29. ​​spring groove; 30. slider; 31. spring; 32. avoidance hole; 100. reaction channel; 101. host. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] Example like Figure 1-Figure 15 As shown, an electro-cleaning method for maintaining stable electrochemical activity on the surface of a working electrode and its application specifically include the following steps: like Fig.14 As shown, S1: a reaction potential of -200mv VS Ag / AgCl is applied to the working electrode 1, and the hypochlorous acid disinfectant water undergoes a reduction reaction with the working electrode 1. The reaction is maintained for 1s, and all peak current data within 1s are collected; S2: After the peak current data is collected, the reaction potential is increased from -200mv VS Ag / AgCl to 1300mv VS Ag / AgCl. At this time, an oxidation reaction of water occurs on the electrode surface of the working electrode 1, and the aqueous solution on the surface of the working electrode 1 becomes strongly acidic. The electrode surface of the working electrode 1 is acid-washed for 2s. S3: After S2 is completed, the reaction potential is reduced from 1300mv VS Ag / AgCl to 0mv VS Ag / AgCl, and the maintenance time is 2s; S4: After S3 is completed, the reaction potential is further reduced from 0mv VS Ag / AgCl to -900mv VS Ag / AgCl. At this time, a water reduction reaction occurs on the electrode surface of the working electrode 1, and the aqueous solution on the surface of the working electrode 1 becomes strongly alkaline. The electrode surface of the working electrode 1 is washed with alkali for 2s. S5: After S4 is completed, the reaction potential is restored from -900 mv VS Ag / AgCl to 0 mv VS Ag / AgCl, and the maintenance time is 3 s; then S1-S5 are repeated to start the next cycle.

[0023] Furthermore, the electrode surface of the working electrode 1 is made of any one of gold, platinum, titanium, and glassy carbon having good electrical conductivity and corrosion resistance.

[0024] Furthermore, the method is used to clean the working electrode of the thin-layer channel electrochemical sensor, such as Figure 1-Figure 13 As shown, the thin-layer channel electrochemical sensor includes a host 101, a docking station 2, a reference electrode module 3 and a working electrode module 4. Figure 2 and Figure 3 As shown, the docking seat 2 is installed inside the host 101, and the working electrode module 4 is installed on the docking seat 2; like Figure 4 and Figure 6 As shown, a tetrafluoroethylene gasket 5 is placed on the upper surface of the working electrode module 4, and the reference electrode module 3 is installed on the working electrode module 4, and the bottom of the reference electrode module 3 is in contact with the tetrafluoroethylene gasket 5, and the tetrafluoroethylene gasket 5 is provided with a thin layer channel 6; like Figure 4 As shown, the reference electrode module 3 is provided with a liquid inlet cavity 7, a reference electrode hole 8 connected to the liquid inlet cavity 7 is provided at the bottom of the reference electrode module 3, a reference electrode 9 connected to the liquid inlet cavity 7 is installed on the top of the reference electrode module 3, and the reference electrode 9 with an Ag / AgCl electrode is selected to provide a known potential reference point as a reference, a liquid inlet structure connected to the liquid inlet cavity 7 is installed on one side of the reference electrode module 3, and the reference electrode module 3 is also provided with a liquid discharge groove 10, and a liquid discharge structure is installed on the top of the liquid discharge groove 10; The working electrode 1 is installed in the working electrode module 4, and the counter electrode 11 is also installed in the working electrode module 4. The reference electrode 9, the working electrode 1, and the counter electrode 11 are all electrically connected to the host 101 for easy regulation; like Figure 5 As shown, the liquid inlet cavity 7, the thin layer channel 6 and the liquid discharge groove 10 are combined into a reaction channel 100, the reference electrode 9 is connected to the reaction channel 100 through the reference electrode hole 8, and the upper surfaces of the working electrode 1 and the counter electrode 11 are connected to the reaction channel 100, so that the working electrode 1 and the hypochlorous acid disinfectant water react; A positioning structure is provided on the docking seat 2 , and the positioning structure is used to enhance the stability among the reference electrode module 3 , the tetrafluoroethylene gasket 5 and the working electrode module 4 .

[0025] Further, such as Figure 6 As shown, a plurality of positioning rods 12 are installed at the bottom of the reference electrode module 3, a positioning socket 13 corresponding to the plurality of positioning rods 12 is provided on the upper surface of the working electrode module 4, and a positioning through hole 14 corresponding to the plurality of positioning rods 12 is provided on the tetrafluoroethylene gasket 5, and the free ends of the plurality of positioning rods 12 pass through the positioning through holes 14 and are plugged into the positioning socket 13; During installation, the reference electrode 9 is installed on the reference electrode module 3 so that the reference electrode 9 is connected to the liquid inlet cavity 7, and the working electrode 1 and the counter electrode 11 are installed on the working electrode module 4; then the tetrafluoroethylene gasket 5 is placed on the upper surface of the working electrode module 4, the positioning perforation 14 is aligned with the positioning socket 13, and then the positioning rod 12 at the bottom of the reference electrode module 3 is inserted into the positioning perforation 14 and the positioning socket 13, so that the liquid inlet cavity 7, the thin layer channel 6 and the liquid discharge groove 10 are combined into a reaction channel 100; the tetrafluoroethylene gasket 5 is clamped by the reference electrode module 3 and the working electrode module 4, and the position of the tetrafluoroethylene gasket 5 is limited by the positioning rod 12 to prevent the tetrafluoroethylene gasket 5 from being offset during operation, thereby affecting the accuracy of the detection; The thickness of the tetrafluoroethylene gasket 5 is 25 μm; The upper surface of the working electrode 1 is circular and has a diameter of 1 mm; The working electrode 1 is located directly below the reference electrode hole 8; By setting the thickness of the tetrafluoroethylene gasket 5 to 25 μm, the distance between the reference electrode hole 8 and the working electrode 1 is precisely controlled at 25 μm, and the thickness of the thin layer channel 6 is also precisely controlled at 25 μm, thereby effectively reducing the solution measurement resistance R value. The upper surface of the working electrode 1 is circular and has a diameter of 1 mm, which can effectively reduce the measurement current density. I , thereby reducing the measurement system I R value, thereby achieving the purpose of accurately measuring the effective chlorine concentration without adding electrolytes.

[0026] Further, such as Figure 7-Figure 9 As shown, a first interface 15 communicating with the liquid inlet cavity 7 is provided on one side of the reference electrode module 3, and a first sealing ring 16 is attached to the inner wall of the first interface 15; The liquid inlet structure includes a first connecting screw rod 17, one end of which is threadedly connected to the first docking port 15 and the end thereof is in contact with the first sealing ring 16, an introduction tube 18 is fixedly embedded inside the first connecting screw rod 17, one end of which passes through the first connecting screw rod 17 and is in communication with the liquid inlet chamber 7; The other end of the first connecting screw rod 17 is fixedly connected to the first screwing part 19, and a second sealing ring 20 is embedded on the side of the first screwing part 19 close to the reference electrode module 3. The other end of the introduction tube 18 passes through the first connecting screw rod 17 and the first screwing part 19, and the end is connected to the sample outlet of the hypochlorous acid disinfectant water production line through a pulsation-free pump (not shown in the figure). The pulsation-free pump is connected to the main unit 101 for signal transmission to facilitate regulation.

[0027] After the reference electrode module 3, the tetrafluoroethylene gasket 5 and the working electrode module 4 are installed, the liquid inlet structure and the liquid discharge structure are installed, specifically: the first screwing part 19 is rotated, and the first screwing part 19 drives the first connecting screw rod 17 to rotate, and then the first connecting screw rod 17 is screwed into the first docking port 15. The first docking port 15 can be isolated from the liquid inlet cavity 7 by the first sealing ring 16, so as to ensure the air tightness inside the liquid inlet cavity 7, and at the same time, it can also prevent the solution to be tested from flowing into the first docking port 15, resulting in an increase in the error of chlorine concentration detection. The second sealing ring 20 can further ensure the air tightness inside the liquid inlet cavity 7. When testing, the hypochlorous acid disinfectant water production line uses a pulsation-free pump to deliver the hypochlorous acid disinfectant water into the introduction pipe 18, and then flows into the reaction channel 100; Further, such as Figure 7 , Fig.10 and Fig.11 As shown, the drainage groove 10 is provided with a second docking port 21, and a third sealing ring 22 is attached to the inner wall of the second docking port 21. The drainage structure includes a second connecting screw rod 23, one end of the second connecting screw rod 23 is threadedly connected to the second docking port 21 and the end thereof is in contact with the third sealing ring 22. A guide tube 24 is fixedly embedded inside the second connecting screw rod 23, and one end of the guide tube 24 passes through the second connecting screw rod 23 and is connected to the drainage groove 10. The other end of the second connecting screw rod 23 is fixedly connected to the second screwing part 25, and a fourth sealing ring 26 is embedded on one side of the second screwing part 25 close to the reference electrode module 3. The other end of the outlet pipe 24 passes through the second screwing part 25 and extends outside. As the pulsation-free pump continuously delivers the hypochlorous acid disinfectant water into the liquid inlet chamber 7, the hypochlorous acid disinfectant water in the thin layer channel 6 is discharged through the outlet pipe 24. By rotating the second screwing portion 25, the second screwing portion 25 drives the second connecting screw rod 23 to rotate, and then screws the second connecting screw rod 23 into the second docking port 21. The third sealing ring 22 can prevent the hypochlorous acid disinfectant from flowing into the second docking port 21, thereby affecting the discharge of the hypochlorous acid disinfectant from the outlet pipe 24. The fourth sealing ring 26 can further ensure the air tightness inside the liquid inlet chamber 7.

[0028] Further, such as Fig.12 and Fig.13 As shown, the positioning structure includes a balance plate 27 and a bolt pressure head 28. Two spring grooves 29 are provided on one side of the inner wall of the docking seat 2. Two sliders 30 are provided on one side of the balance plate 27. The sliders 30 are slidably connected in the spring grooves 29. Springs 31 are provided in both spring grooves 29, and one end of the spring 31 is fixedly connected to the slider 30, and the other end is fixedly connected to the top of the inner cavity of the spring groove 29. The top of the docking seat 2 is threadedly connected with a bolt pressure head 28, and the bottom end of the bolt pressure head 28 is threadedly penetrated through the docking seat 2 and abuts against the upper surface of the balance plate 27; like Figure 3 and Fig.13 As shown, the balance plate 27 is provided with two avoidance holes 32, the top of the reference electrode 9 is located in one of the avoidance holes 32, and the second screwing portion 25 is located in the other avoidance hole 32; After the reference electrode 9, the liquid inlet structure, the liquid discharge structure, the reference electrode module 3, the working electrode 1, the counter electrode 11, the working electrode module 4, and the tetrafluoroethylene gasket 5 are installed, the working electrode module 4 is placed on the docking seat 2, and the bolt pressing head 28 is rotated clockwise, and the bolt pressing head 28 presses the balance plate 27 downward, and the balance plate 27 slides downward along the spring groove 29 through the slider 30 so that the bottom of the balance plate 27 contacts the top of the reference electrode module 3, and the reference electrode module 3 is squeezed, so that the reference electrode module 3, the tetrafluoroethylene gasket 5 and the working electrode module 4 are closely fitted; In the present invention, the balancing plate 27 is driven to move by rotating the bolt pressure head 28, so that when the balancing plate 27 moves to any position, under the action of the bolt pressure head 28 and the spring 31, the balancing plate 27 will not reset or automatically move down, so that the staff can adjust the reference electrode module 3, the tetrafluoroethylene gasket 5 and the working electrode module 4 in the middle.

[0029] During the test, the hypochlorous acid disinfectant water production line continuously delivers the hypochlorous acid disinfectant water into the introduction pipe 18 through the sample outlet and the pulsation-free pump, flows into the liquid inlet chamber 7 along the first interface 15 and flows into the thin layer channel 6 through the reference electrode hole 8, and the hypochlorous acid disinfectant water is measured by voltammetry (CV), as shown in FIG. Fig.14 As shown in the figure, a reaction potential of -200mv VSAg / AgCl is applied to the working electrode 1, and the hypochlorous acid disinfectant water undergoes a reduction reaction with the working electrode 1, namely: 2HClO+H + +e=H2O+2HCl+1 / 2O2, the reaction duration is 1s, and all peak current data within 1s are collected; like Fig.14 As shown in the figure, after the peak current data acquisition is completed, the reaction potential is increased from -200mv VS Ag / AgCl to 1300mv VS Ag / AgCl and maintained for 2s. At this time, water oxidation reaction occurs on the electrode surface of working electrode 1, that is: H2O=2H + +2e+1 / 2O2, at this time, the aqueous solution on the surface of the working electrode 1 is strongly acidic, and the surface of the working electrode 1 is acid-washed to remove inorganic dirt and negatively charged acid radical ions attached to the surface of the working electrode 1; After 2s, the reaction potential is reduced from 1300mv VS Ag / AgCl to 0mv VS Ag / AgCl, and the maintenance time is 2s. At this time, the surface of the working electrode stops reacting, and the hypochlorous acid disinfectant in the liquid inlet chamber 7 continuously flows into the thin layer channel 6, and then the strongly acidic aqueous solution and dirt on the surface of the working electrode 1 are discharged along the drainage groove 10 and the outlet pipe 24 along with the hypochlorous acid disinfectant. Then, the reaction potential is reduced from 0mv VS Ag / AgCl to -900mv VS Ag / AgCl, and the maintenance time is 2s. At this time, a water reduction reaction occurs on the electrode surface of the working electrode 1, that is: 2H2O+2e=H2+2OH - At this time, the aqueous solution on the surface of the working electrode 1 becomes strongly alkaline, and the electrode surface of the working electrode 1 is alkaline-washed to remove organic dirt on the surface of the working electrode 1 and metal ions attached to the surface of the working electrode 1; After 2s, the reaction potential is restored from -900mv VS Ag / AgCl to 0mv VS Ag / AgCl for 3s. At this time, the surface of the working electrode stops reacting. As the hypochlorous acid disinfectant in the liquid inlet chamber 7 continuously flows into the thin layer channel 6, the strongly alkaline aqueous solution and dirt on the surface of the working electrode 1 are discharged along the drainage groove 10 and the outlet pipe 24 along with the hypochlorous acid disinfectant (that is, the cleaning work is completed). When the dirt is away from the working electrode 1, the next effective chlorine concentration detection can be carried out to enter the next cycle.

[0030] In the present invention, the detection and cleaning cycle is continuously carried out to ensure that the electrochemical activity on the surface of the working electrode 1 remains stable for a long time during the measurement process, thereby ensuring the stability and accuracy of the detection data. Therefore, the surface of the working electrode 1 can be cleaned without removing the reference electrode module 3, the tetrafluoroethylene gasket 5 and the working electrode module 4, which is convenient and quick.

[0031] In the present invention, in order to ensure the accuracy of the experiment, voltammetry (CV) was used to measure the hypochlorous acid disinfectant water with different concentrations. Fig.15 As shown, the effective chlorine concentration in hypochlorous acid disinfected water shows a good linear relationship in the range of 5.0 to 2000 mg / L. Therefore, hypochlorous acid disinfected water products with an effective chlorine concentration in the range of 5.0 to 2000 mg / L can be tested to see whether they meet the standards.

[0032] However, as is well known to those skilled in the art, the working principles and wiring methods of the working electrode 1, the counter electrode 11, the reference electrode 9, the main unit 101 and the pulsation-free pump are commonplace and are conventional means or common knowledge, and will not be elaborated here. Those skilled in the art may make any selections according to their needs or convenience.

[0033] The above different embodiments can be combined, replaced and used in conjunction with each other.

[0034] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0035] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An electro-cleaning method for maintaining stable electrochemical activity on the surface of a working electrode, characterized in that: The specific steps include: S1: applying a reaction potential of -200 mv VS Ag / AgCl to the working electrode (1), the hypochlorous acid disinfectant water undergoes a reduction reaction with the working electrode (1), the reaction is maintained for 1 second, and all peak current data within 1 second are collected; S2: After the peak current data is collected, the reaction potential is raised from -200 mv VS Ag / AgCl to 1300 mv VS Ag / AgCl. At this time, an oxidation reaction of water occurs on the electrode surface of the working electrode (1), and the aqueous solution on the surface of the working electrode (1) becomes strongly acidic. The electrode surface of the working electrode (1) is acid-washed for 2 seconds. S3: After the completion of S2, the reaction potential is reduced from 1300 mv VS Ag / AgCl to 0 mv VS Ag / AgCl, and the maintenance time is 2 s; S4: After the completion of S3, the reaction potential is further reduced from 0 mv VS Ag / AgCl to -900 mv VS Ag / AgCl. At this time, a water reduction reaction occurs on the electrode surface of the working electrode (1), and the aqueous solution on the surface of the working electrode (1) becomes strongly alkaline. The electrode surface of the working electrode (1) is washed with alkaline for 2 seconds. S5: After the completion of S4, the reaction potential is restored from -900 mv VS Ag / AgCl to 0 mv VS Ag / AgCl for 3 seconds; and then S1-S5 are repeated to start the next cycle.

2. The electro-cleaning method for maintaining stable electrochemical activity on the surface of a working electrode according to claim 1, characterized in that: The electrode surface of the working electrode (1) is made of any one of gold, platinum, titanium and glassy carbon.

3. The use of the electro-cleaning method for maintaining stable electrochemical activity on the surface of a working electrode according to claim 1, characterized in that: Used for cleaning a working electrode of a thin-layer channel electrochemical sensor, the thin-layer channel electrochemical sensor comprising a host (101), a docking seat (2), a reference electrode module (3) and a working electrode module (4), the docking seat (2) being mounted inside the host (101), and the working electrode module (4) being mounted on the docking seat (2); A tetrafluoroethylene gasket (5) is placed on the upper surface of the working electrode module (4), the reference electrode module (3) is mounted on the working electrode module (4), and the bottom of the reference electrode module (3) is in contact with the tetrafluoroethylene gasket (5), and the tetrafluoroethylene gasket (5) is provided with a thin layer channel (6); The reference electrode module (3) is provided with a liquid inlet cavity (7), the bottom of the reference electrode module (3) is provided with a reference electrode hole (8) connected to the liquid inlet cavity (7), the top of the reference electrode module (3) is provided with a reference electrode (9) connected to the liquid inlet cavity (7), the reference electrode (9) and a liquid inlet structure connected to the liquid inlet cavity (7) are installed on one side of the reference electrode module (3), the reference electrode module (3) is further provided with a liquid discharge groove (10), and the top of the liquid discharge groove (10) is provided with a liquid discharge structure; The working electrode (1) is installed in a working electrode module (4), and a counter electrode (11) is also installed in the working electrode module (4), and the working electrode (1) and the counter electrode (11) are both electrically connected to the host (101); The liquid inlet cavity (7), the thin layer channel (6) and the liquid discharge groove (10) are combined to form a reaction channel (100); the reference electrode (9) is connected to the reaction channel (100) via the reference electrode hole (8); and the upper surfaces of the reference electrode (9), the working electrode (1) and the counter electrode (11) are connected to the reaction channel (100); The docking seat (2) is provided with a positioning structure, which is used to enhance the stability between the reference electrode module (3), the tetrafluoroethylene gasket (5) and the working electrode module (4).

4. The use of the electro-cleaning method for maintaining stable electrochemical activity on the surface of a working electrode according to claim 3, characterized in that: A plurality of positioning rods (12) are installed at the bottom of the reference electrode module (3); a positioning socket (13) corresponding one-to-one to the plurality of positioning rods (12) is provided on the upper surface of the working electrode module (4); a positioning through-hole (14) corresponding one-to-one to the plurality of positioning rods (12) is provided on the tetrafluoroethylene gasket (5); and free ends of the plurality of positioning rods (12) pass through the positioning through-holes (14) and are plugged into the positioning sockets (13); The thickness of the tetrafluoroethylene gasket (5) is 25 μm; The upper surface of the working electrode (1) is circular and has a diameter of 1 mm; The working electrode (1) is located directly below the reference electrode hole (8).

5. The use of the electro-cleaning method for maintaining stable electrochemical activity on the surface of a working electrode according to claim 3, characterized in that: A first pair of interfaces (15) communicating with the liquid inlet cavity (7) is provided on one side of the reference electrode module (3), and a first sealing ring (16) is attached to the inner wall of the first pair of interfaces (15); The liquid inlet structure comprises a first connecting screw rod (17), one end of the first connecting screw rod (17) is threadedly connected to the first docking port (15) and the end thereof abuts against the first sealing ring (16), an introduction tube (18) is fixedly embedded inside the first connecting screw rod (17), one end of the introduction tube (18) passes through the first connecting screw rod (17) and is in communication with the liquid inlet chamber (7); The other end of the first connecting screw rod (17) is fixedly connected to a first screwing portion (19), and a second sealing ring (20) is embedded on a side of the first screwing portion (19) close to the reference electrode module (3). The other end of the introduction tube (18) passes through the first connecting screw rod (17) and the first screwing portion (19), and the end is connected to a sample outlet of a hypochlorous acid disinfectant water production line via a pulsation-free pump, and the pulsation-free pump is connected to a host (101) for signal transmission.

6. The use of the electro-cleaning method for maintaining stable electrochemical activity on the surface of a working electrode according to claim 5, characterized in that: The drainage groove (10) is provided with a second docking port (21), the inner wall of the second docking port (21) is provided with a third sealing ring (22), the drainage structure comprises a second connecting screw rod (23), one end of the second connecting screw rod (23) is threadedly connected to the second docking port (21) and the end thereof is in contact with the third sealing ring (22), a guide tube (24) is fixedly embedded inside the second connecting screw rod (23), one end of the guide tube (24) passes through the second connecting screw rod (23) and is in communication with the drainage groove (10); The other end of the second connecting screw rod (23) is fixedly connected to a second screwing portion (25); a fourth sealing ring (26) is embedded on a side of the second screwing portion (25) close to the reference electrode module (3); the other end of the outlet pipe (24) passes through the second screwing portion (25) and extends outside; as the pulsation-free pump continuously delivers the hypochlorous acid disinfectant water into the liquid inlet chamber (7), the hypochlorous acid disinfectant water in the thin layer channel (6) is discharged through the outlet pipe (24).

7. Application of the electro-cleaning method for maintaining stable electrochemical activity on the surface of a working electrode according to claim 6, characterized in that: The positioning structure comprises a balance plate (27) and a bolt pressure head (28); two spring grooves (29) are provided on one side of the inner wall of the docking seat (2); two sliders (30) are provided on one side of the balance plate (27); the sliders (30) are slidably connected in the spring grooves (29); a spring (31) is provided in each of the two spring grooves (29); one end of the spring (31) is fixedly connected to the slider (30) and the other end is fixedly connected to the top of the inner cavity of the spring groove (29); The top of the docking seat (2) is threadedly connected with a bolt pressure head (28), and the bottom ends of the two bolt pressure heads (28) are threadedly passed through the docking seat (2) and abut against the upper surface of the balance plate (27); The balancing plate (27) is provided with two avoidance holes (32), the top of the reference electrode (9) is located in one of the avoidance holes (32), and the second screwing portion (25) is located in the other avoidance hole (32).

8. The use of the electro-cleaning method for maintaining stable electrochemical activity on the surface of a working electrode according to claim 5, characterized in that: In S1, a reaction potential of -200 mv VS Ag / AgCl is applied to the working electrode (1), and the hypochlorous acid disinfectant water undergoes a reduction reaction with the working electrode (1), namely: 2HClO+H + +e=H2O+2HCl+1 / 2O2, the reaction duration is 1s, and all peak current data within 1s are collected.

9. The use of the electro-cleaning method for maintaining stable electrochemical activity on the surface of a working electrode according to claim 5, characterized in that: After the peak current data acquisition is completed, the reaction potential is increased from -200mv VS Ag / AgCl to 1300mv VS Ag / AgCl and maintained for 2s. At this time, water oxidation reaction occurs on the electrode surface of the working electrode (1), that is, H2O=2H + +2e+1 / 2O2, at this time, the aqueous solution on the surface of the working electrode (1) is strongly acidic, and the surface of the working electrode (1) is acid-washed to remove inorganic dirt and negatively charged acid radical ions attached to the surface of the working electrode (1); After 2 seconds, the reaction potential is reduced from 1300 mv VS Ag / AgCl to 0 mv VS Ag / AgCl and maintained for 2 seconds. At this time, as the hypochlorous acid disinfectant in the liquid inlet chamber (7) continuously flows into the thin layer channel (6), the strongly acidic aqueous solution on the surface of the working electrode (1) is discharged along the drainage groove (10) and the outlet pipe (24) along with the hypochlorous acid disinfectant.

10. The use of the electro-cleaning method for maintaining stable electrochemical activity on the surface of a working electrode according to claim 5, characterized in that: After the S3 is completed, the reaction potential is lowered from 0mv VS Ag / AgCl to -900mv VS Ag / AgCl and maintained for 2s. At this time, a water reduction reaction occurs on the electrode surface of the working electrode (1), namely: 2H2O+2e=H2+2OH - At this time, the aqueous solution on the surface of the working electrode (1) becomes strongly alkaline, and the electrode surface of the working electrode (1) is washed with alkali to remove organic dirt on the surface of the working electrode (1) and metal ions attached to the surface of the working electrode (1); After 2 seconds, the reaction potential is restored from the reaction potential of -900 mv VS Ag / AgCl to 0 mv VS Ag / AgCl and maintained for 3 seconds. At this time, as the hypochlorous acid disinfectant in the liquid inlet chamber (7) continuously flows into the thin layer channel (6), the strongly alkaline aqueous solution on the surface of the working electrode (1) is discharged along the drainage groove (10) and the outlet pipe (24) along with the hypochlorous acid disinfectant.

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