Environment control unit for scanning electrochemical probe microscope

Abstract

The invention provides an environment control unit for a scanning electrochemical probe microscope, which comprises a sealing pool, a cavity is arranged in the sealing pool, the sealing pool is provided with an air inlet, an air outlet, a probe access port and a transparent observation window, the sealing pool is internally provided with a sample table, and the sample table is provided with an air inlet, an air outlet, a probe access port and a transparent observation window. And the probe extends into the cavity through the probe access port and then is close to the surface of the sample. The micro-nano probe is used in the scanning electrochemical probe microscope technology, specific atmosphere is introduced around the micro-nano probe (the diameter of the top end is dozens of nanometers to dozens of microns), specific humidity is kept, interference of air on reaction is avoided, or gaseous reactants are provided for the reaction, and proceeding of the reaction is promoted.

Description

Technical Field

[0001] The invention relates to the technical field of scanning electrochemical probe microscopes, and in particular to an environment control unit for a scanning electrochemical probe microscope. Background Art

[0002] Scanning electrochemical probe microscopy has greatly improved the spatial resolution of electrochemical research and provided a powerful research tool for analyzing the correspondence between electrode microstructure and activity. It mainly includes scanning electrochemical microscopy (SECM), scanning ion conductivity microscopy (SICM), scanning electrochemical cell microscopy (SECCM) and other technologies. SECM uses a solid electrode of glass-wrapped metal wire, while SICM and SECCM use probes drawn from hollow glass tubes. In addition, in SECM and SICM devices, the sample needs to be immersed in the electrolyte, while SECCM relies on the formation of microdroplets at the bottom of the probe to form an electrochemical microreaction cell after contact with the sample surface, so the sample does not need to be immersed in the electrolyte. Given that the probe size of the scanning electrochemical probe microscope is mostly between tens of nanometers and tens of micrometers, the reaction environment has an important influence on its signal acquisition. On the one hand, when studying air-sensitive electrodes and electrolytes (such as batteries), it is often necessary to put the equipment into a glove box for testing, which puts higher requirements on the operating space and experiments. On the other hand, when used to study electrochemical reactions involving gas (such as CO2 electroreduction, O2 electroreduction and H2 electrooxidation, etc.), gas-saturated electrolytes are usually used (reaching a saturated dissolved state), but the solubility of gas in the electrolyte is very low and the transmission speed is slow, which makes it difficult to meet the reaction requirements, thereby limiting the normal progress of the reaction. In addition, for micro-electrochemical reaction cells, humidity control in the environment is very important, and the natural volatilization of the electrolyte seriously affects the signal feedback and imaging quality. For this reason, it is necessary to develop an efficient environmental control unit that matches the scanning electrochemical probe microscope to maintain specific parameters such as atmosphere and humidity during the scanning imaging experiment. However, there are still many problems that need to be solved in the existing designs, such as poor sealing effect caused by the openings in the electrode wires, large internal space or complex structure, resulting in low gas replacement efficiency. Summary of the invention

[0003] According to the above technical problems, an environment control unit for a scanning electrochemical probe microscope is provided.

[0004] The technical means adopted by the present invention are as follows:

[0005] An environmental control unit for a scanning electrochemical probe microscope comprises a sealed pool, a chamber is provided inside the sealed pool, an air inlet, an air outlet, a probe access port and a transparent observation window are arranged on the sealed pool, a sample stage is arranged inside the sealed pool, and the probe is extended into the chamber through the probe access port and approaches the sample surface.

[0006] Furthermore, a chamber bottom plate is provided at the bottom of the sealing pool, a base is provided under the chamber bottom plate, the sealing pool is fixed by clamping the base with a spring installed on the XY-axis piezoelectric ceramic displacement stage, a buckle plate is provided on the base, a clip matching the buckle plate is provided on the chamber, and the chamber bottom plate is sealed to the chamber by the buckle and the buckle plate.

[0007] Furthermore, the sample to be tested is connected to an electrode connector embedded on the inner wall of the chamber through a wire.

[0008] Furthermore, the current amplifier is connected to the outside of the electrode connector, the plastic hose is connected to the gas controlled by the flow meter, the gas enters the sealed pool from the air inlet, and is discharged from the air outlet after filling the chamber.

[0009] Furthermore, the air inlet and the air outlet are not in a straight line.

[0010] Furthermore, a rubber ring seal is provided at the probe access port, a rubber film is sleeved on the outside of the rubber ring, and an opening for the probe to enter is provided at the rubber film.

[0011] Furthermore, a CCD industrial camera is placed on the transparent observation window side of the environmental control unit, and the position and magnification are adjusted to view the position of the probe relative to the sample surface through the transparent observation window.

[0012] Furthermore, the probe is fixed on a Z-axis piezoelectric ceramic, which is fixed on a coarse adjustment stage. The probe is lowered by moving the coarse adjustment stage, and the Z-axis piezoelectric ceramic is then precisely controlled by a control system to control the displacement of the probe. At the same time, the distance between the probe and the sample surface reaches a specific value through a current feedback mechanism.

[0013] Furthermore, the environmental control unit can be applied to a scanning electrochemical microscope, a scanning ion conductivity microscope, and a scanning electrochemical cell microscope.

[0014] Furthermore, when applied to scanning electrochemical microscopes and scanning ion conductivity microscopes, the gas introduced through the environmental control unit mainly forms a protective gas around the probe; when applied to scanning electrochemical cell microscopes, the probe and the sample surface are in contact through micro-droplets to form an electrochemical micro-reaction cell. The introduced gas can not only form a protective atmosphere around the micro-reaction cell to maintain a specific humidity, but also act as a reactant. A part of the gas reacts by forming a gas-liquid-solid three-phase interface, and the other part of the gas will gradually dissolve in the electrolyte and diffuse to the liquid-solid interface to participate in the reaction.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] 1. The sealing pool of the present invention has good sealing effect, small size, light weight, simple internal structure, almost no dead volume, and is convenient for rapid replacement of internal gas.

[0017] 2. The present invention uses the metal springs on the XY-axis piezoelectric ceramic displacement stage to fix the sealing pool to the piezoelectric ceramic surface through the circular base, so as to perform precise horizontal movement and facilitate disassembly.

[0018] 3. The present invention introduces gas only into a small space around the probe, thereby improving gas transmission efficiency and avoiding waste caused by excessive use of gas.

[0019] 4. The present invention adopts a glass or quartz transparent window to facilitate the CCD industrial camera to observe the internal sample and probe, and avoids the influence of the direct use of the sealing pool plastic material and curvature on the imaging of the CCD industrial camera.

[0020] 4. The circuit connection component is embedded in the wall of the sealed pool. The electrode is connected to this component through a wire, and then connected to the signal amplifier outside the sealed pool by a wire to measure the electrode signal. This connection method can avoid air leakage caused by direct lead wires, avoid the pulling force of the wire on the sample, and facilitate sample disassembly.

[0021] 6. The air inlet and outlet are connected to the external gas through the Luer interface, and the connection / disconnection operation is simple. In addition, their positions on the sealed cell wall are asymmetrically designed and are not in the same straight line, so that the gas can fully fill the sealed cell before being discharged, while avoiding the influence of direct blowing of the intake air flow on the volatilization of the electrolyte. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0023] Figure 1 It is a front view of an embodiment of the present invention.

[0024] Figure 2 It is a side view of an embodiment of the present invention.

[0025] Figure 3 FIG. 4 is a top view of an embodiment of the present invention.

[0026] Figure 4 Schematic diagram of fixing connectors for environmental control unit.

[0027] Figure 5 The following are the actual application diagrams of the present invention, where (a) is a real picture of the environmental control unit, (b) is a CCD industrial camera photo of the SECCM probe on the sample observed through the window, where the edge of the window is marked with a dotted line, and (c) is an enlarged picture of the SECCM probe part. Figure 6 Schematic diagram of gas transmission around the probe in the environmental control unit, where (a) is a schematic diagram of the protective atmosphere in SECM technology, (b) is a schematic diagram of the protective atmosphere in SICM technology, (c) is a schematic diagram of the protective atmosphere or gas participating in the reaction around the probe in SECCM technology, and (d) is an enlarged diagram of the gas diffusion scheme in the micro-droplet reaction cell. Serial numbers ①②③ represent possible gas transmission paths: ① participates in the reaction by constructing a gas-liquid-solid interface, and ②-③ first dissolve into the electrolyte and then diffuse to the liquid-solid interface to participate in the reaction.

[0028] In the figure: 1. Chamber, 2. Transparent observation window, 3. Probe access port, 4. Probe, 5. Rubber ring, 6. Rubber skin, 7. Electrode connector, 8. Air inlet, 9. Air outlet, 10. Plastic hose, 11. Sample stage, 12. Buckle, 13. Chamber bottom plate, 14. Buckle plate, 15. Round base, 16. CCD industrial camera, 17. XY-axis piezoelectric ceramic translation stage, 18. Connector, 19. Connector fixing screw, 20. Metal spring, 21. Spring fixing screw. DETAILED DESCRIPTION

[0029] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0030] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings 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. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. 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.

[0031] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0032] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, the numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be clear that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The technology, methods and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be regarded as part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0033] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention: the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0034] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below their position devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0035] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0036] like Figures 1 to 6 As shown, an embodiment of the present invention discloses an environmental control unit for a scanning electrochemical probe microscope, including a sealed pool, a chamber 1 is provided inside the sealed pool, an air inlet 8, an air outlet 9, a probe access port 3 and a transparent observation window 2 are provided on the sealed pool, a sample stage 11 is provided inside the sealed pool, and a probe 4 is extended into the chamber through the probe access port and approaches the sample surface. The present invention is used in scanning electrochemical probe microscope technology to introduce a specific atmosphere around a micro-nano probe (with a top diameter of tens of nanometers to tens of micrometers) to avoid air interference with the reaction or provide gaseous reactants for the reaction, thereby promoting the reaction.

[0037] Furthermore, a chamber bottom plate 13 is provided at the bottom of the sealing pool, and a base 15 is provided below the chamber bottom plate. The sealing pool is fixed through the circular base 15 by a metal spring 20 on the XY-axis piezoelectric ceramic displacement stage 17. One end of the spring is fixed to the connecting piece 18 by a screw 21. The connecting piece 18 is fixed to the XY-axis piezoelectric ceramic displacement stage 17 by a screw 19. A buckle plate 14 is provided on the base, and a buckle 12 matching the buckle plate is provided on the chamber. The chamber bottom plate and the chamber are sealed by the buckle and the buckle plate.

[0038] Furthermore, the sample to be tested is connected to the electrode connector 7 embedded on the inner wall of the chamber through a wire. The sample itself is a conductive material and is connected to the wire as an electrode.

[0039] Furthermore, the current amplifier is connected to the outside of the electrode connector, the plastic hose 10 is connected to the gas controlled by the flow meter, the gas enters the sealed pool from the air inlet, and is discharged from the air outlet after filling the chamber.

[0040] Furthermore, the air inlet and the air outlet are not in a straight line. In addition, as a preferred embodiment, the present invention uses a Luer connector embedded in the wall of the environmental control unit to complete the air intake and exhaust. The present invention has a small internal volume, and the gas flows in a horizontal circular direction. The gas easily fills the sealed pool, thereby improving the efficiency of the experiment.

[0041] Furthermore, a rubber ring 5 is provided at the probe access port for sealing, a rubber film 6 is sleeved on the outside of the rubber ring, and an opening for the probe to enter is provided at the rubber film.

[0042] Furthermore, the environmental control unit is provided with an inclined transparent observation window, and the CCD industrial camera 16 is placed outside the observation window. There is a preset angle between the microscope lens and the observation window, so that the external light source is incident on the lens after being reflected on the sample surface, ensuring the light intensity and clarity during observation, and adjusting the position and magnification to view the position and distance of the probe relative to the sample surface through the transparent observation window. As an optional embodiment, the observation window of the present invention is a half-moon-shaped opening inlaid with glass or quartz material. At the same time, there is a preset inclination angle between the observation window and the bottom plate, which is 60±5° in the present invention, almost perpendicular to the CCD industrial camera lens, making the observation field of view wider and clearer.

[0043] Furthermore, the probe is fixed on a Z-axis piezoelectric ceramic, which is fixed on a coarse adjustment stage. The probe is lowered by moving the coarse adjustment stage, and the Z-axis piezoelectric ceramic is then precisely controlled by a control system to control the displacement of the probe. At the same time, the distance between the probe and the sample surface reaches a specific value through a current feedback mechanism.

[0044] Furthermore, the environmental control unit can be applied to SECM, SICM, and SECCM.

[0045] Furthermore, in SECM and SICM, the gas introduced through the environmental control unit mainly forms a special atmosphere around the probe to protect the air-sensitive electrode materials and electrolytes, or to increase the solubility of the reaction gas in the solution by slowly dissolving. In SECCM, the probe and the sample surface are contacted by micro-droplets to form an electrochemical micro-reaction cell. The introduction of gas can maintain a specific humidity around the micro-reaction cell to prevent the micro-droplets from changing in shape and size due to volatilization, thereby affecting the feedback signal and imaging quality; forming a specific atmosphere to protect the air-sensitive electrode materials and electrolytes; in view of the small size of the micro-droplets, the atmosphere in the environmental control unit can also act as a reactant, part of the gas reacts by forming a gas-liquid-solid three-phase interface, and the other part of the gas will quickly diffuse from the micro-droplets to the inside, continuously replenishing the species consumed by the reaction at the liquid-solid interface; the gaseous species produced by the reaction are discharged from the outlet under the impetus of the intake air flow.

[0046] As an optional implementation, the sample stage can be rotated and raised and lowered to facilitate adjustment of the horizontal orientation and position of the sample relative to the probe.

[0047] As an optional embodiment, the opening above the sealing pool for accessing the probe can be made of a pipette tip and sealed by fixing the rubber layer with an O-ring. The rubber cover can be directly obtained from commonly used rubber gloves in laboratories. The material is common, low-cost and easy to replace.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An environmental control unit for a scanning electrochemical probe microscope, characterized in that: The sealed pool comprises a chamber inside which is provided with an air inlet, an air outlet, a probe access port and a transparent observation window, a sample stage inside which is provided, and the probe is extended into the chamber through the probe access port and approaches the sample surface.

2. The environmental control unit for a scanning electrochemical probe microscope according to claim 1, characterized in that: A chamber bottom plate is arranged at the bottom of the sealing pool, a base is arranged under the chamber bottom plate, the sealing pool is fixed by clamping the base with a spring installed on the XY-axis piezoelectric ceramic displacement stage, a buckle plate is arranged on the base, a clip matching the buckle plate is arranged on the chamber, and the chamber bottom plate is sealed with the chamber by the buckle and the buckle plate.

3. The environmental control unit for a scanning electrochemical probe microscope according to claim 1, characterized in that: The sample to be tested is connected to the electrode connector embedded on the inner wall of the chamber through a wire.

4. The environmental control unit for a scanning electrochemical probe microscope according to claim 1, characterized in that: The current amplifier is connected to the outside of the electrode connector, and the plastic hose is connected to the gas controlled by the flow meter. The gas enters the sealed pool from the gas inlet and is discharged from the gas outlet after filling the chamber.

5. The environmental control unit for a scanning electrochemical probe microscope according to claim 1, characterized in that: The air inlet and the air outlet are not in a straight line.

6. The environmental control unit for a scanning electrochemical probe microscope according to claim 1, characterized in that: The probe access port is provided with a rubber ring seal, the outside of the rubber ring is sleeved with a rubber film, and the rubber film is provided with an opening for the probe to enter.

7. The environmental control unit for a scanning electrochemical probe microscope according to claim 1, characterized in that: The CCD industrial camera is placed on the transparent observation window side of the environmental control unit, and the position and magnification are adjusted to view the position of the probe relative to the sample surface through the transparent observation window.

8. The environmental control unit for a scanning electrochemical probe microscope according to claim 1, characterized in that: The probe is fixed on the Z-axis piezoelectric ceramic, which is fixed on the coarse adjustment stage. The probe is lowered by moving the coarse adjustment stage, and the Z-axis piezoelectric ceramic is controlled by the control system to accurately control the displacement of the probe. At the same time, the distance between the probe and the sample surface reaches a specific value through the current feedback mechanism.

9. The environmental control unit for a scanning electrochemical probe microscope according to claim 1, characterized in that: The environmental control unit can be applied to a scanning electrochemical microscope, a scanning ion conductivity microscope, and a scanning electrochemical cell microscope.

10. The environmental control unit for a scanning electrochemical probe microscope according to claim 1, characterized in that: Applied to scanning electrochemical microscopes and scanning ion conductivity microscopes, the gas introduced through the environmental control unit mainly forms a protective gas around the probe; applied to scanning electrochemical cell microscopes, the probe and sample surface are in contact through micro-droplets to form an electrochemical micro-reaction cell. The introduced gas can not only form a protective atmosphere around the micro-reaction cell to maintain a specific humidity, but also act as a reactant. Part of the gas reacts by forming a gas-liquid-solid three-phase interface, and the other part of the gas will gradually dissolve in the electrolyte and diffuse to the liquid-solid interface to participate in the reaction.

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