An in-situ electrochemical cell and detection method for synchrotron radiation infrared testing

Abstract

This invention relates to an in-situ electrochemical reaction cell and detection method for synchrotron radiation infrared (SIR) testing, comprising a working electrode stage, a base, a cell body, an infrared viewing window, and a top cover. The working electrode stage passes through an opening in the base and cell body, with the sample to be tested placed on top. The feed rate of the threaded base is controlled to ensure close contact with the planar infrared viewing window. The synchrotron radiation infrared testing port is coupled to an inclined surface surrounding the central opening of the top cover to form an infrared detection channel. A working electrode lead is provided on one side of the base. Reference electrode slots, counter electrode slots, electrolyte pump in slots, and electrolyte pump out slots are provided on the four sides of the cell body, respectively connected to an external electrochemical working platform and a circulation device. A central opening is provided in the cell body, with serrated edges on the upper end of the opening wall, communicating with a liquid storage groove around the opening to form an electrochemical detection micro-region. This invention fully utilizes the advantages of the synchrotron radiation infrared light source, simulates a real electrochemical detection environment, has good coupling, is easy to assemble and disassemble, has a simple and easy detection method, and provides reliable data.

Description

Technical Field

[0001] This invention relates to the field of spectroelectrochemical technology, and in particular to an in-situ electrochemical cell and detection method for synchrotron radiation infrared testing. Background Technology

[0002] In-situ monitoring of the dynamic processes at the interfaces of energy conversion catalysts, such as the formation and evolution of intermediate products, is an effective means to fully understand the mechanisms of energy conversion and is crucial for the rational design of efficient, inexpensive, and stable novel energy conversion catalysts. Infrared spectroscopy can detect the intrinsic molecular vibrations of functional groups at the catalyst interface, providing rich information on interface chemistry. Moreover, the testing method is simple, rapid, label-free, and requires no damaging pretreatment of the sample, making it widely used for in-situ characterization of heterogeneous catalytic mechanisms. However, in in-situ electrochemical-infrared spectroscopy detection, the liquid electrolyte severely weakens the infrared signal intensity, and the adsorption and re-adsorption of complex gas / solid / liquid multiphase products under operating conditions pose extremely high requirements for the detection sensitivity of infrared spectroscopy. Synchrotron radiation infrared spectroscopy, in addition to possessing the molecular fingerprint effect of conventional infrared spectroscopy, also has many excellent characteristics of synchrotron radiation sources, such as high brightness, good collimation, and continuous spectrum, especially providing higher spectral signal intensity and good spatial and temporal resolution for micro-area samples. Combining synchrotron radiation infrared spectroscopy with in-situ electrochemical detection can greatly improve the sensitivity of in-situ electrochemical detection. However, there is currently a lack of publicly available national invention patents in this area.

[0003] Currently published patents typically design various transparent windows to couple different spectrometers with in-situ electrochemical cells. Examples include a multifunctional in-situ interface research and detection cell for spectroscopic applications proposed by Central South University (CN103115869A) and an in-situ electrochemical-optical coupled research spectroscopic cell (CN103033474A), and a sum-frequency spectroscopic in-situ flowing thin-layer spectroscopic electrochemical reaction cell proposed by the Institute of Chemistry, Chinese Academy of Sciences (CN102539328A). All these designs employ semi-cylindrical transparent windows, allowing for continuous adjustment of the incident light angle from a small starting point, simplifying the optical path. However, they cannot effectively couple to planar synchrotron radiation infrared testing ports. To enhance the infrared signal, active materials are often directly plated onto the bottom plane of the transparent window, utilizing the principle of surface-enhanced total internal reflection to prevent absorption of the spectral signal by the solution. While these designs can simulate real electrochemical reactions, they also increase the fabrication difficulty of the in-situ electrochemical cell. Furthermore, the diversity of samples and electrolytes limits its applicability, and the repeatability of detection needs improvement. Furthermore, thin-layer flow electrochemical cell designs are often used to reduce secondary adsorption interference and improve the signal-to-noise ratio. Examples include a thin-layer flow electrolytic cell (CN105403553A) proposed by the University of Science and Technology of China for in-situ electrochemical Raman spectroscopy detection, a simulated battery device (CN110320476A) proposed by the Institute of Physics, Chinese Academy of Sciences for in-situ detection of gas generation from liquid batteries, and an electrochemical thin-layer flow detection cell (CN103983720A) proposed by the University of Shanghai for Science and Technology. In these designs, the sample is directly exposed to the electrolyte, making it susceptible to edge effects and unable to fully simulate the real electrochemical detection environment. Therefore, it is necessary to comprehensively optimize the in-situ electrochemical cell design for the synchrotron radiation infrared testing port. Summary of the Invention

[0004] The purpose of this invention is to provide an in-situ electrochemical cell for synchrotron infrared testing and its detection method. The in-situ electrochemical cell provided by this invention can fully utilize the advantages of synchrotron infrared light sources, simulate real electrochemical processes, is easy to assemble and disassemble, and has a simple and easy detection method, providing accurate and reliable data.

[0005] This invention provides an in-situ electrochemical cell for synchrotron infrared testing, comprising:

[0006] A working electrode stage, comprising a threaded base, a polytetrafluoroethylene outer jacket, and a glassy carbon electrode core, wherein a groove is cut into the upper part of the threaded base to provide the glassy carbon electrode core, and a polytetrafluoroethylene outer jacket is provided around the glassy carbon electrode core;

[0007] Preferably, the threaded base material is a conductor;

[0008] Preferably, the diameter of the glassy carbon electrode core is less than or equal to 5 mm.

[0009] The base has a central hole with threads machined on the inner wall of the hole, a working electrode lead is provided on one side of the base, and fastening bolts are provided at the four corners of the base. The base is made of a conductive material.

[0010] The pool body, which is fixed to the base by fastening bolts, is square with a central opening. The upper end of the opening wall has serrations, and the outer perimeter of the opening wall has an annular coaxial liquid storage groove. The outer perimeter of the liquid storage groove has an annular shallow groove. The wall thickness of the central opening is about 2-5mm, and the serrations at the upper end of the opening wall are about 1-5mm deep and communicate with the liquid storage groove on the outer perimeter of the opening wall. A sealing ring is installed in the annular shallow groove, with a diameter slightly smaller than the wire diameter of the sealing ring and a depth slightly less than 1 / 2 of the wire diameter of the sealing ring. The four sides of the pool body are provided with reference electrode slots, counter electrode slots, electrolyte pump in slots, and electrolyte pump out slots. Fastening bolt holes are provided on the upper and lower surfaces of the pool body, corresponding to the fastening bolts of the upper cover and the base.

[0011] Preferably, the pool material is polytetrafluoroethylene, polyethylene terephthalate, polyvinyl chloride, or plexiglass;

[0012] Preferably, the reference electrode is a calomel electrode, a silver-silver chloride electrode, a mercury-mercury oxide electrode, a mercury-mercurous sulfate electrode, or a standard hydrogen electrode;

[0013] Preferably, the counter electrode is a platinum wire or a carbon rod;

[0014] Preferably, both the reference electrode and the counter electrode are provided with threaded sleeves, which are inserted into corresponding slots and fixed and sealed by threads and sealing rings;

[0015] Preferably, the electrolyte pump inlet conduit and the pump outlet conduit are respectively inserted into corresponding slots and connected to an external circulation device through threaded sleeves and sealing rings on the conduits. The external circulation device includes a circulation pump, a gas flow control pump, conduits, and an electrolyte tank.

[0016] The beneficial effect of the liquid storage groove and the toothed design of the pore wall is to avoid the edge effect caused by the disturbance of the thin-layer flow electrochemical micro-region, and to simulate the real electrochemical detection environment.

[0017] An infrared viewing window is installed above the pool body;

[0018] Preferably, the window material is diamond, silicon, germanium, barium fluoride, or zinc selenide;

[0019] Preferably, the viewing window is a planar circular piece with a diameter larger than the diameter of the annular shallow groove.

[0020] The working electrode stage passes through the base and the opening in the pool body, and the sample to be tested is placed on top of it. The feed amount through the threaded base is as close as possible to the infrared viewing window above the pool body.

[0021] A top cover is provided above the infrared window. The top cover has a central opening, and an annular coaxial inclined surface is provided around the opening to couple with the synchrotron radiation infrared test port. The top cover is fixed to the pool body by fastening bolts.

[0022] Preferably, the diameter of the central opening in the upper cover is slightly larger than the diameter of the working electrode platform;

[0023] Preferably, the angle between the inclined plane and the horizontal is less than 90°, and the outer diameter is larger than the synchrotron infrared test port.

[0024] The beneficial effects of the planar infrared window and the inclined design of the top cover are to achieve good coupling between the in-situ electrochemical cell and the synchrotron infrared test port. At the same time, the inclined surface is also conducive to the emission of infrared signals, making it easier for the detector to receive effective signals and obtain infrared spectroscopic signals with high signal-to-noise ratio.

[0025] The present invention provides a detection method for in-situ electrochemical-synchrotron radiation infrared testing using the above-mentioned in-situ electrochemical cell, employing a multi-step focusing measurement method to achieve reliable data, comprising the following steps:

[0026] (1) The sample to be tested is dropped onto the glassy carbon electrode core of the working electrode stage of the above-mentioned in-situ electrochemical cell and dried.

[0027] (2) Install the working electrode stage, tighten the bolts to fix the base and cell body of the above-mentioned in-situ electrochemical cell, focus the synchrotron infrared light on the surface of the sample to be tested, and collect the infrared spectrum.

[0028] (3) Select the reference electrode and the counter electrode according to different electrochemical processes, and fix them to the device in step (2) by means of threads and sealing rings;

[0029] (4) Select electrolyte and saturated atmosphere according to different electrochemical processes. Connect the electrolyte inlet and outlet pipes to the device in step (3) through threads and sealing rings. Start the circulation pump of the external circulation device to pump the gas-saturated electrolyte into the storage tank. After forming a stable circulating electrolyte, refocus the synchrotron infrared light on the surface of the sample to be tested and collect the infrared spectrum with the infrared spectrum collected in step (2) as the background.

[0030] (5) Install the infrared window, fix the top cover of the above-mentioned in-situ electrochemical cell to the device in step (4) with fastening bolts, adjust the feed amount of the threaded base of the working electrode stage to control the thickness of the electrolyte film between the infrared window and the sample to be tested to be on the order of micrometers, reduce the signal interference of the electrolyte, refocus the synchrotron infrared light on the surface of the sample to be tested, and collect the infrared spectrum with the infrared spectrum collected in step (4) as the background.

[0031] (6) Connect the reference electrode, counter electrode and working electrode leads of the device in step (5) to the external electrochemical working platform, and power on the device. Perform pre-stabilization pretreatment according to the control voltage, current and scanning time of different samples to be tested.

[0032] (7) After the electrochemical signal on the surface of the sample to be tested is stabilized, control the voltage, current and scanning time, and collect infrared spectra at different electrochemical stages with the infrared spectrum collected in step (5) as the background.

[0033] The advantages of this invention compared to the prior art are:

[0034] (1) The present invention achieves good coupling with the synchrotron infrared test port through the design of planar infrared window and upper cover slope, which can make full use of the high brightness, high throughput and high collimation characteristics of synchrotron infrared light source in micro area. At the same time, the slope is also conducive to the emission of infrared signal, making it easier for the detector to receive effective signal and obtain infrared spectral signal with high signal-to-noise ratio.

[0035] (2) This invention can effectively avoid edge effects, simulate the real electrochemical detection environment, and more intuitively identify reaction intermediates in the energy conversion process. It can be used for in-situ research on the evolution of reaction intermediates in the energy conversion process.

[0036] (3) The in-situ electrochemical cell described in this invention does not have a specific window design, has low processing cost, and is easy to assemble and disassemble;

[0037] (4) The detection method described in this invention is simple and easy to implement. It can gradually obtain reliable infrared signals of the sample to be tested, avoid interference from false signals caused by the focus not being on the sample, and ensure the authenticity and reliability of the obtained data. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the structure of an in-situ electrochemical cell used for synchrotron infrared testing;

[0039] Figure 2 This is a schematic diagram of the working electrode stage of the present invention;

[0040] Figure 3 This is a top view of the pool structure of the present invention;

[0041] Figure 4 This is a schematic diagram of the pool structure from below according to the present invention;

[0042] Figure 5 This is a schematic diagram of the threaded sleeves in the reference electrode and counter electrode of the embodiment;

[0043] Figure 6 This is a comparison of LSV curves tested using a conventional electrochemical cell in the embodiment and an in-situ electrochemical cell of the present invention.

[0044] Figure 7 These are the infrared spectral curves of different scanning voltages in the embodiment.

[0045] Among them, 1 is the working electrode stage, 2 is the base, 3 is the pool body, 4 is the infrared window, 5 is the top cover, 11 is the working electrode lead, 12 is the fastening bolt, 13 is the sealing ring, 31 is the reference electrode slot, 32 is the counter electrode slot, 33 is the electrolyte pump in slot, 34 is the electrolytic flow pump out slot, 35 is the liquid storage groove, 36 is the annular shallow groove, 101 is the threaded base, 102 is the polytetrafluoroethylene outer jacket, 103 is the glassy carbon electrode core, 104 is the sample to be tested, and 105 is the threaded sleeve. Detailed Implementation

[0046] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0047] like Figure 1 As shown, the present invention provides an in-situ electrochemical cell for synchrotron radiation infrared testing, including a working electrode stage 1, as shown in the figure. Figure 2 The working electrode stage includes a threaded base 101, a polytetrafluoroethylene (PTFE) jacket 102, and a glassy carbon electrode core 103. The glassy carbon electrode core is slotted above the threaded base and surrounded by a PTFE jacket. The threaded base is made of copper, and the glassy carbon electrode core has a diameter of 5 mm. A sample 104 to be tested is placed on the working electrode stage; in this embodiment, a powdered NiFe-MOF material is used. The base 2 has a central hole with threads machined into its inner wall. A working electrode lead 11 is located on one side of the base, and fastening bolts 12 are located at the four corners of the base. The base is made of aluminum-magnesium alloy. A pool 3 is located above the base. Figure 3 This is a top-view structural diagram of the pool body. The pool body has dimensions of 6cm × 6cm × 1.5cm. It has a central opening with a diameter of 1.06cm and an inner wall thickness of 2mm. The upper end of the opening has serrations approximately 4mm deep. A liquid storage groove 35 is provided around the outer perimeter of the opening wall. The outer diameter of the liquid storage groove is 1.63cm from the center, and the depth is 8mm. Electrolyte is stored inside; in this embodiment, 1MKOH saturated O2 electrolyte is used. An annular shallow groove 36 with a diameter of 3.7cm is provided around the liquid storage groove for placing an O-ring seal 13. The wire diameter of the O-ring is 1.8mm. The diameter of the annular shallow groove is 1.6mm, and the depth is 0.8mm. The pool body material is polytetrafluoroethylene (PTFE), which is resistant to strong alkalis. Reference electrode slots 31, counter electrode slots 32, electrolyte pump in slots 33, and electrolyte pump out slots 34 are respectively provided on the four sides. In this embodiment, the electrolyte is used as described above. Figure 5An Ag / AgCl reference electrode and a platinum wire counter electrode with threaded sleeves 105 are added. These electrodes are inserted into their corresponding slots, fitted with sealing rings, and the threaded sleeves are tightened. The electrode leads are connected to an external electrochemical working platform. The electrolyte pump inlet and outlet conduits of the external circulation device are fitted with sealing rings, inserted into their corresponding slots, and the threads are tightened. The electrolyte pool is pumped into a saturated atmosphere via a gas flow control pump. Figure 4 As shown, a groove with a depth of 5mm is cut into the lower surface of the pool body to accommodate the base and lead wires. Fastening bolt holes are located at the four corners, corresponding to the fastening bolts on the base. A circular BaF2 infrared window 4 with a diameter of 3.8cm is located above the pool body. A top cover 5 is located above the infrared window, with a central opening of 1cm in diameter. An inclined plane with a 20° angle to the horizontal is formed around the opening, with the outer diameter of the inclined plane approximately 4cm from the diameter. The synchrotron radiation infrared test port directly contacts the inclined plane. Fastening bolts are located at the four corners of the top cover. A sealing ring is fitted onto the working electrode stage, which passes through the opening in the base and pool body. The feed amount of the threaded base of the working electrode stage is adjusted to fit as closely as possible to the infrared window, forming a micron-sized electrolyte layer between the sample to be tested and the infrared window. The base is fixed to the pool body, and the pool body is fixed to the top cover with fastening bolts.

[0048] In the specific implementation process, the sample to be tested is first dropped onto the glassy carbon electrode core of the working electrode stage and dried. The working electrode stage is then installed, and the base and cell body are fixed with fastening bolts. The Ag / AgCl reference electrode and platinum wire counter electrode are installed, along with the electrolyte pump inlet and outlet conduits. Synchrotron infrared light is focused onto the surface of the sample to be tested, and the infrared spectrum is collected as the primary background spectrum. The circulation pump in the external circulation device is started to pump O2-saturated 1M KOH electrolyte into the storage tank. After a stable circulating electrolyte is formed, the synchrotron infrared light is refocused onto the surface of the sample to be tested, and the infrared spectrum is collected against the primary background spectrum as the secondary background spectrum. The infrared window is installed, and the cell body and top cover are fixed with fastening bolts. The feed rate of the threaded base of the working electrode stage is adjusted to control the electrolyte film thickness between the infrared window and the sample to be tested to be on the order of micrometers. The synchrotron infrared light is refocused onto the surface of the sample to be tested, and the infrared spectrum is collected against the secondary background spectrum as the tertiary background spectrum. Connect the reference electrode, counter electrode, and working electrode leads to the external electrochemical working platform and power it on. Set the potential to 1.5V and the scan time to ~20min. After the electrochemical signal of the sample to be tested reaches stability, modify the electrochemical detection parameters and collect electrochemical data.

[0049] The polarization curves of the samples were tested using the in-situ electrochemical cell of this invention. The test voltage range was 1.2-1.8 V vs RHE, and the scan rate was 20 mV / s. Under the same detection conditions, the polarization curves of the samples were scanned using a conventional electrochemical cell, as shown below. Figure 6As shown, the polarization curves of samples detected using the in-situ electrochemical cell of this invention agree well with those detected using a conventional electrochemical cell, indicating that the in-situ electrochemical cell of this invention can simulate a real electrochemical detection environment. To detect infrared spectral signals under electrochemical conditions, this embodiment employs a constant potential method, fixing the voltage at 1.2V, 1.4V, and 1.6V respectively, and maintaining this voltage for 10 minutes, with infrared spectral acquisition using three background spectra as the background.

[0050] like Figure 7 As shown, wavenumbers up to 1050 cm⁻¹ can be observed at a voltage of 1.4V. -1 The appearance of an infrared signal peak likely corresponds to the reaction intermediate -OO-. The increased peak intensity at 1.6V indicates that this peak corresponds to the reaction intermediate of the sample during the electrochemical process. To verify this conclusion, the saturated electrolyte solution can be subjected to isotopic substitution, such as replacing it with H2O. 18 Replace with H2O 16 Or saturate O 18 2. Change the atmosphere to O 16 2. Perform the same operation as above. Based on the position and displacement of the infrared signal peaks of the isotopes with the applied voltage, the infrared signal peaks of oxygen adsorption can be ruled out, the structure of the reaction intermediates can be further clarified, and the evolution of the reaction intermediates can be inferred.

[0051] The above description is merely a preferred embodiment of the present invention and should not be construed as limiting the scope of the present invention. All equivalent changes and modifications made in accordance with the scope of the patent and the contents of the specification should still fall within the scope of the present invention.

Claims

1. An in-situ electrochemical cell for synchrotron infrared testing, characterized in that: The device includes a working electrode stage, a base, a pool body, an infrared viewing window, and a top cover. The base and pool body, and the pool body and top cover are respectively fixed with fastening bolts. The base has a central opening, a working electrode lead is installed on one side, and fastening bolts are installed at the four corners. The pool body has a central opening with serrated edges on the upper end of the opening wall, an annular coaxial liquid storage groove on the outer periphery of the opening wall, and an annular shallow groove on the outer periphery of the liquid storage groove. The four sides of the pool body have reference electrode slots, counter electrode slots, electrolyte pump in slots, and electrolyte pump out slots. Fastening bolt holes are provided on the upper and lower surfaces, corresponding to the fastening bolts of the top cover and base. The working electrode stage passes through the openings in the base and pool body, and the sample to be tested is placed on top of it. The feed rate of the threaded base is as close as possible to the infrared viewing window above the pool body. The top cover has a central opening with an annular coaxial inclined surface on the outer periphery of the opening, which couples with the synchrotron radiation infrared test port. Fastening bolts are installed at the four corners of the top cover. The diameter of the central opening in the top cover is slightly larger than the diameter of the working electrode stage; the angle between the inclined plane and the horizontal is less than 90°, and the outer diameter is larger than the synchrotron infrared test port; the wall thickness of the central opening in the pool body is 2-5mm.

2. The in-situ electrochemical cell for synchrotron infrared testing according to claim 1, characterized in that: The working electrode stage includes: a threaded base, a polytetrafluoroethylene (PTFE) jacket, and a glassy carbon electrode core; the glassy carbon electrode core is provided with a groove on the top of the threaded base, and the glassy carbon electrode core is surrounded by a PTFE jacket; the threaded base is a conductor; the diameter of the glassy carbon electrode core is less than or equal to 5 mm.

3. The in-situ electrochemical cell for synchrotron infrared testing according to claim 1, characterized in that: The inner wall of the central opening of the base is threaded, and the base material is a conductor.

4. The in-situ electrochemical cell for synchrotron infrared testing according to claim 1, characterized in that: The pool body is a cube. The inner walls of the reference electrode slot, the counter electrode slot, the electrolyte pump in slot, and the electrolyte pump out slot are all threaded. The tooth pattern at the upper end of the hole wall is 1-5mm deep and communicates with the liquid storage groove set on the outer periphery of the hole wall. A sealing ring is set in the annular shallow groove, with a diameter slightly smaller than the sealing ring wire diameter and a depth slightly smaller than 1 / 2 of the sealing ring wire diameter. The pool body material is polytetrafluoroethylene, polyethylene terephthalate, polyvinyl chloride, or plexiglass; The reference electrode is a calomel electrode, a silver-silver chloride electrode, a mercury-mercury oxide electrode, a mercury-mercurous sulfate electrode, or a standard hydrogen electrode; The counter electrode is a platinum wire or a carbon rod; Both the reference electrode and the counter electrode are equipped with threaded sleeves, which are inserted into corresponding slots and fixed and sealed by threads and sealing rings; The electrolyte pump inlet and outlet conduits are respectively inserted into corresponding slots and connected to an external circulation device through threaded sleeves and sealing rings on the conduits. The external circulation device includes a circulation pump, a gas flow control pump, conduits, and an electrolyte tank.

5. The in-situ electrochemical cell for synchrotron infrared testing according to claim 1, characterized in that: The infrared window material is diamond, silicon, germanium, barium fluoride, or zinc selenide; the infrared window is a planar circular piece with a diameter larger than the diameter of the annular shallow groove.

6. The in-situ electrochemical cell for synchrotron infrared testing according to claim 1, characterized in that: A sealing ring is installed between the working electrode stage and the central opening of the pool body.

7. A detection method for an in-situ electrochemical cell for synchrotron radiation infrared testing based on any one of claims 1-6, characterized in that: A multi-step focusing measurement method is used to ensure the accuracy and reliability of the data, including the following steps: (1) The sample to be tested is dropped onto the glassy carbon electrode core of the working electrode stage of the above-mentioned in-situ electrochemical cell and dried; (2) Install the working electrode stage, tighten the bolts to fix the base and cell body of the above-mentioned in-situ electrochemical cell, focus the synchrotron infrared light on the surface of the sample to be tested, and collect the infrared spectrum; (3) Select the reference electrode and the counter electrode according to different electrochemical processes, and fix them to the device in step (2) by means of threads and sealing rings; (4) Select electrolyte and saturated atmosphere according to different electrochemical processes. Connect the electrolyte inlet and outlet conduits to the device in step (3) through threads and sealing rings. Start the circulation pump of the external circulation device to pump the atmosphere-saturated electrolyte into the storage tank. After forming a stable circulating electrolyte, refocus the synchrotron infrared light on the surface of the sample to be tested and collect the infrared spectrum with the infrared spectrum collected in step (2) as the background. (5) Install the infrared window, fix the top cover of the above-mentioned in-situ electrochemical cell to the device in step (4) with fastening bolts, adjust the feed amount of the threaded base of the working electrode stage to control the thickness of the electrolyte film between the infrared window and the sample to be tested to be on the order of micrometers, reduce the signal interference of the electrolyte, refocus the synchrotron infrared light on the surface of the sample to be tested, and collect the infrared spectrum with the infrared spectrum collected in step (4) as the background. (6) Connect the reference electrode, counter electrode and working leads of the device in step (5) to the external electrochemical working platform, and power on the device. Perform pre-stabilization pretreatment according to the control voltage, current and scanning time of different samples to be tested. (7) After the electrochemical signal on the surface of the sample to be tested is stabilized, control the voltage, current and scanning time, and collect infrared spectra at different electrochemical stages with the infrared spectrum collected in step (5) as the background.

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