Multi-channel high-temperature electrochemical sample holder and in-situ test sample preparation method

Abstract

The invention relates to the technical field of high-temperature electrochemical experiments, in particular to a multi-channel high-temperature electrochemical sample holder and an in-situ test sample preparation method. The multi-channel high-temperature electrochemical sample holder comprises a base, a ceramic sample holder and a plurality of groups of probe assemblies which are sequentially arranged from bottom to top, the ceramic sample holder is of an integrated structure and comprises a sample part, a connecting part and a fixing part, the plurality of groups of probe assemblies are detachably connected with the ceramic sample holder and the base through the fixed bottom plate, and each group of probe assemblies independently comprises a metal probe, a probe arm and a probe arm bracket and is used for fixing a sample, realizing electrical isolation and switching on a sample circuit. The multi-channel high-temperature electrochemical sample holder provided by the invention can adapt to laser heating and vacuum experiment environments, simplifies the sample preparation process, and remarkably improves the efficiency and reliability of high-temperature electrochemical experiments and widens the application range of the high-temperature electrochemical experiments.

Description

Technical Field

[0001] The present invention relates to the technical field of high-temperature electrochemical experiments, and in particular to a multi-channel high-temperature electrochemical sample holder and an in-situ test sample preparation method. Background Art

[0002] When conducting in-situ high-temperature electrochemical experiments in vacuum, near-atmospheric pressure, or atmospheric pressure systems, they often face complex sample preparation steps, low success rates, and limited experimental operating temperatures. This is mainly because existing experimental methods require stacking the heat spreader, conductive gold mesh, sample, wire, and insulating ceramic layer by layer, and fixing them to the sample holder by spot welding stainless steel sheets. This preparation method usually takes about two hours and not only has a high probability of poor electrode contact, but also has difficulty supporting high-temperature experiments above 600°C due to the large heat dissipation area.

[0003] In order to more efficiently utilize synchrotron radiation light source time and improve the success rate of high-temperature electrochemical experiments, it is urgent to develop an in-situ sample holder with excellent thermal insulation performance, easy sample preparation and high circuit connection success rate.

[0004] X-ray photoelectron spectroscopy (XPS) is a key technology in surface analysis, primarily based on the photoelectric effect. When X-rays irradiate a sample surface, they can excite electrons in the atomic orbitals of specific elements within the sample, allowing them to gain sufficient kinetic energy to escape from their nuclei and become free electrons. These released photoelectrons are detected by an energy analyzer, and the kinetic energy information can be used to infer the electron's binding energy, thereby revealing the sample's elemental composition, chemical state, and electronic structure. XPS is primarily used to analyze the elemental composition and chemical state within a depth of 1 to 10 nanometers below the surface of a material, capable of detecting nearly all elements with an atomic number greater than or equal to 3. Its advantages include non-destructive analysis, zero contamination, rapid measurement, and high precision, making it a core tool for studying surface chemistry. The development of near-ambient-pressure XPS technology has further overcome the ultra-high vacuum limitations of traditional XPS, expanding its application to conditions closer to real-world conditions, such as near-ambient-pressure atmospheres or specific temperatures. Medium- and high-temperature solid oxide batteries and electrolyzers play a crucial role in achieving the "dual carbon" goals, both in energy conversion and environmental protection. High-temperature electrochemical systems encompass key devices such as solid oxide fuel cells (SOFCs), electrolytic cells (SOECs), and other high-temperature reactors. These devices are widely used in clean energy production, energy storage, and carbon capture and utilization. In situ APXPS characterization of electrode materials at high temperatures, near-ambient pressures, and applied voltages facilitates researchers' understanding of surface reaction mechanisms and plays a crucial role in this research area. However, high-temperature APXPS experiments present significant challenges. Key challenges include achieving stable voltage or current output within the limited sample holder space, enabling real-time monitoring of electrical signals under high temperature and specific atmospheric conditions, and effectively revealing the sample's electrochemical and photoelectrochemical properties and surface physicochemical changes. However, currently available commercial XPS sample holders still have significant limitations in enabling in situ measurements under high temperature, specific atmospheres, and applied voltage or current conditions. In particular, due to the unique structure of the sample holder and the high temperature and vacuum conditions required for APXPS, no sample holder in China is suitable for in situ high-temperature electrochemical characterization under these complex conditions, and relevant international examples only support single-channel measurements. For example, in 2010, the Advanced Light Source (ALS) team at Lawrence Berkeley National Laboratory in Stanford, USA, proposed an in-situ electrochemical fixture for use in conventional vacuum systems. This device, consisting of an electrochemical fixture unit and a ceramic heater, partially addresses the requirements for in-situ characterization experiments under high temperatures, specific atmospheres, and applied voltages. However, ceramic heaters have numerous drawbacks, including slow heating rates, temperature instability, short lifespan, large size, occupancy of the sample rod circuit path, and the tendency to adsorb contaminants, which can contaminate experimental samples. These issues pose particular challenges for experiments requiring high cleanliness.At the BL02B01 beamline of the Shanghai Synchrotron Radiation Facility (SFSF), ceramic heaters have been replaced by laser heaters. While laser heaters offer advantages such as rapid heating rates and precise temperature control, they rely on time-consuming and labor-intensive soldering sample preparation methods. Currently, APXPS high-temperature electrochemical experiments at this beamline suffer from limited success rates and low operating temperatures, limiting experimental efficiency and effectiveness.

[0005] Therefore, developing a high-temperature electrochemical sample holder suitable for vacuum / near-atmospheric pressure sample transfer systems to achieve higher heating efficiency and more test channels has become a key issue that needs to be addressed urgently. Summary of the Invention

[0006] In response to the problems of existing high-temperature electrochemical experiment sample holders such as complex sample preparation, low efficiency, poor temperature control performance, and a limited number of in-situ test channels, the present invention proposes a new sample holder suitable for high-temperature electrochemical experiments. By adopting a 3D-printed ceramic sample holder and probe assembly, it can cooperate with laser heating, greatly simplifying the in-situ test sample preparation process, and realizing rapid sample fixation, efficient thermal management and reliable electrical contact.

[0007] To achieve the above-mentioned and other related purposes, the present invention adopts the following technical solutions:

[0008] The first aspect of the present invention provides a multi-channel high-temperature electrochemical sample holder, comprising a base, a ceramic sample holder and several groups of probe assemblies arranged in sequence from bottom to top; the ceramic sample holder is an integrated structure, comprising a sample part, a connecting part and a fixing part, the fixing parts are arranged on both sides of the ceramic sample holder and are detachably connected to the base, the sample part is used to carry the sample, and the connecting part integrally connects the sample part and the fixing part; the several groups of probe assemblies are detachably connected to the ceramic sample holder and the base via a fixed base plate; each group of probe assemblies independently includes a metal probe, a probe arm and a probe arm bracket, the metal probe is arranged at the head end of the probe arm, the probe arm bracket is provided with a rotating shaft and a groove for accommodating the probe arm, the probe arm is rotatably connected to the rotating shaft through a rotating shaft hole, the tail end of the probe arm is connected to the fixed base plate through an elastic connecting member, and the lifting of the metal probe is achieved by pressing the second end of the probe arm.

[0009] In some embodiments of the present invention, the sample portion is a hollow annular structure, with multiple vertical limit columns distributed axially on the top, and the gaps between adjacent limit columns form limit grooves; and / or, the fixing portion is two ceramic strips, which are arranged on both sides of the sample portion, one end of the ceramic strip is connected to the connecting portion, and the other end is provided with a ceramic sample rack mounting hole.

[0010] In some embodiments of the present invention, the height of the limiting column is consistent; and / or the cross-section of the limiting column is a curved trapezoid, and the shorter base (upper base) of the curved trapezoid is located on the inner ring of the circular structure, and the longer base (lower base) is located on the outer ring of the circular structure.

[0011] In some embodiments of the present invention, the front end face of the probe arm is provided with a probe mounting hole for inserting a metal probe, and the side wall thereof is provided with a fastening screw for fastening the metal probe; and / or, the rotating shaft includes a steel inner core passing through the probe arm and a ceramic rotating shaft located on both sides of the probe arm and embedded in the side walls of the probe arm bracket; and / or, the rear end of the probe arm is provided with a vertical through hole, a screw is installed in the through hole, the elastic connecting piece is sleeved on the lower part of the screw, and the lower end of the screw is connected to the fixed base plate.

[0012] In some embodiments of the present invention, a plurality of mounting holes are coaxially provided on the fixed base plate and the base, and the mounting holes correspond to the mounting holes of the ceramic sample holder; the fixing portion of the fixed base plate and the ceramic sample holder is detachably connected and fixed to the base by fasteners passing through the mounting holes and the mounting holes of the ceramic sample holder.

[0013] In some embodiments of the present invention, four circumferentially distributed screw holes are provided on the fixed base plate and the base, and the fasteners are countersunk screws; at the connection positions at both ends: the countersunk screws sequentially pass through the screw holes at both ends of the fixed base plate, the mounting holes on the fixed part of the ceramic sample holder and the screw holes at both ends of the base and are fixed by nuts; at the middle connection position: the countersunk screws sequentially pass through the screw holes in the middle of the fixed base plate, the alumina gasket and the screw holes on the base and are fixed by nuts.

[0014] In some embodiments of the present invention, the sample holder further includes a connecting gold wire, one end of which is wound around the screw and the other end is connected to an electrical connection terminal on the base to achieve conduction between the probe assembly and the electrical connection terminal.

[0015] In some embodiments of the present invention, the sample holder further comprises a ceramic tube, which is sleeved on the outside of the connecting gold wire to prevent short circuit.

[0016] In some embodiments of the present invention, the sample holder further includes a sample standard line, which is a gold wire with a flat end, and is used to provide an experimental reference sample.

[0017] In some embodiments of the present invention, the metal probe is made of platinum-iridium alloy.

[0018] A second aspect of the present invention provides an in-situ test sample preparation method using the multi-channel high-temperature electrochemical sample holder, comprising the following steps:

[0019] Step 1: Place the silicon carbide wafer in the limiting groove of the ceramic sample holder, place a gold mesh of the same size as the silicon carbide wafer on the silicon carbide wafer, connect the gold mesh to the electrical connection terminal on the base with a gold wire, wrap one end of the gold wire around the screw at the rear end of the probe arm, and connect the other end to the electrical connection terminal on the base;

[0020] Step 2: Press the tail end of the probe arm to lift the metal probe, place the sample on the gold mesh, adjust the position so that the sample falls into the limit groove of the ceramic sample holder, and adjust the position of the metal probe tip so that the tip touches the contact point of the sample to achieve connection;

[0021] Step 3: Use a multimeter to test whether the circuit from the electrical connection terminal on the base to the sample contact is insulated from the ground. If it is insulated, proceed to the next step. If it is short-circuited to the ground, check whether the connecting gold wire or fixing screw is in contact with the sample holder;

[0022] Step 4: Use a multimeter to test whether the circuit from the electrical connection terminal on the base to the sample contact is conductive. If it is conductive, the sample preparation is complete. If not, it is necessary to check whether the needle tip of the metal probe successfully contacts the sample contact and whether the gold wire connecting the needle tip and the electrical connection terminal on the base is broken.

[0023] As described above, the multi-channel high-temperature electrochemical sample holder of the present invention has the following beneficial effects:

[0024] 1. The multi-channel high-temperature electrochemical sample holder provided by the present invention adopts a DLP-based The ceramic sample holder prepared by 3D printing technology can adapt to laser heating and vacuum experimental environments, significantly improving the efficiency, reliability and applicability of high-temperature electrochemical experiments, and providing a more efficient tool for materials science and energy technology research. The ceramic sample holder is made of dense ceramic material with low thermal conductivity, and is further designed with a limit groove with a specific shape to reduce the contact area between the ceramic sample holder and the sample. It can achieve rapid heating and fixation of the sample through laser heating, while ensuring the stability of the sample when placed vertically to prevent it from falling off. Compared with traditional ceramic heaters, the ceramic sample holder in the present invention has significant advantages in heating performance and temperature control: it can adapt to laser heating, shortening the time to 700°C from one hour to ten minutes, and increasing the extreme temperature from 700°C to 1400°C, providing a more efficient thermal management solution for high-temperature electrochemical experiments. In addition, compared with the traditional spot welding sample preparation method, after the ceramic sample holder replaces the metal Mo sheet, it greatly reduces heat conduction and contact heat dissipation, so that the sample temperature is increased by about 200°C under the same laser heating power, and a higher extreme temperature is achieved.

[0025] 2. The probe assembly design of the multi-channel high-temperature electrochemical sample holder provided by the present invention further simplifies the in-situ test sample preparation process, shortening the sample preparation time from two hours to five minutes, while significantly reducing the probability of poor electrochemical contact. Due to the limitations of the commercial vacuum sample transfer system (STLC series) and its sample holder design, the number of in-situ test channels is upper bounded by four. When using traditional sample holders for high-temperature catalytic / electrochemical experiments, the channels need to be utilized for heating, temperature measurement, and other functions, leaving only two test channels. The present invention uses a 3D-printed ceramic sample holder combined with laser heating and in-situ electrochemical impedance spectroscopy temperature measurement to enable all four channels of the vacuum sample transfer system to be used for electrochemical characterization, paving the way for new in-situ APXPS experiments such as high-temperature electrochemical titration.

[0026] 3. The multi-channel high-temperature electrochemical sample holder provided by the present invention has been successfully implemented in more than ten cases at the BL02B01 beamline of the Shanghai Synchrotron Radiation Light Source, assisting multiple research groups at Tsinghua University, Westlake University, and ShanghaiTech University to complete more than 100 hours of in-situ XPS test experiments, and has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of the structure of a multi-channel high-temperature electrochemical sample holder according to one embodiment of the present invention.

[0028] Figure 2 Schematic diagram of the structure of a ceramic sample holder for a multi-channel high-temperature electrochemical sample holder according to an embodiment of the present invention Figure 1 .

[0029] Figure 3 Schematic diagram of the structure of a ceramic sample holder for a multi-channel high-temperature electrochemical sample holder according to an embodiment of the present invention Figure 2 .

[0030] Figure 4 This is a schematic structural diagram of a probe assembly of a multi-channel high-temperature electrochemical sample holder according to an embodiment of the present invention.

[0031] Figure 5 This is a perspective view of the structure of a probe assembly of a multi-channel high-temperature electrochemical sample holder according to one embodiment of the present invention.

[0032] Figure 6 This is a picture of the sample obtained by the traditional welding sample preparation method.

[0033] Figure 7 Schematic diagram of the in-situ XPS test sample structure using traditional welding sample preparation method to achieve electrochemical connection.

[0034] Figure 8 Schematic diagram of the in-situ XPS test sample structure using a reed to fix the sample to achieve electrochemical connection.

[0035] Figure 9 This is a structural photograph of the in-situ XPS test sample obtained using the reed fixation method.

[0036] Figure 10 This is a picture of a sample obtained using the sample preparation method of the multi-channel high-temperature electrochemical sample holder of the present invention.

[0037] Figure 11 Measurements of PrOx-modified (5 nm) LSCF thin film electrodes under different applied bias voltages, where (a) is the Fe L-edge XAS spectrum, (b) is the Co L-edge XAS spectrum, and (c) is a photo of the prepared sample and sample holder.

[0038] Figure 12 In situ measurement of the valence state change of the electrochemical memory resistor channel material under high temperature conditions, where (a) is the in situ measured O-kedge PEY-XAS spectrum, and (b) is the sample and sample holder under the in situ test state.

[0039] Reference numerals:

[0040] 1-base; 2-ceramic sample holder; 3-probe assembly; 4-fixed base plate; 11-electrical connection terminal; 21-sample part; 22-connecting part; 23-fixing part; 31-metal probe; 32-probe arm; 33-probe arm bracket; 41-ceramic base; 42-screw hole; 43-countersunk screw; 44-alumina gasket; 211-limiting column; 212-limiting groove; 231-ceramic sample holder mounting hole; 321-through hole; 322-screw; 323-elastic connector; 324-probe mounting hole; 325-fastening screw; 331-rotating shaft; 331a-steel inner core; 331b-ceramic rotating shaft; 332-groove; X-silicon carbide wafer. DETAILED DESCRIPTION

[0041] A multi-channel high-temperature electrochemical sample holder and an in-situ test sample preparation method of the present invention will be described in detail below with reference to the accompanying drawings.

[0042] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for understanding and reading by those familiar with this technology, and are not used to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the efficacy and purpose that can be achieved by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description and are not used to limit the scope of the implementation of the present invention. Changes or adjustments in their relative relationships should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0043] The first aspect of the present invention provides a multi-channel high temperature electrochemical sample holder, referring to Figures 1 to 5 , including a base 1, a ceramic sample holder 2 and several groups of probe assemblies 3 arranged in sequence from bottom to top; the ceramic sample holder 2 is an integrated structure, including a sample portion 21, a connecting portion 22 and a fixing portion 23, the fixing portion 23 is arranged on both sides of the ceramic sample holder, and is detachably connected to the base 1, the sample portion 21 is used to carry the sample, and the connecting portion 22 is integrally connected to the fixing portion 21 and the fixing portion 23; the several groups of probe assemblies 3 are detachably connected to the ceramic sample holder 2 and the base 1 through a fixed bottom plate 4, and each group of probe assemblies 3 independently includes The metal probe 31, probe arm 32 and probe arm bracket 33 are used to fix the sample, achieve electrical isolation and connect the sample circuit. The metal probe 31 is arranged at the head end of the probe arm 32. The middle of the probe arm bracket 33 is provided with a rotating shaft 331 and a groove 332 for accommodating the probe arm 32. The probe arm 32 is rotatably connected to the rotating shaft 331 through the rotating shaft hole. The tail end of the probe arm 32 is connected to the fixed base plate 4 through an elastic connecting member 323; the lifting of the metal probe 31 is achieved by pressing the second end of the probe arm 32. The multi-channel high-temperature electrochemical sample holder provided by the present invention, the base 1 is a universal base for vacuum / near-normal pressure sample transfer systems, which can be used for XPS (X-ray photoelectron spectroscopy), AES (Auger electron spectroscopy), LEED / SEM (low-energy electron diffraction / scanning electron microscopy) and other tests, and its structure will not be repeated here, such as the STLC series vacuum sample transfer system of Thermionics; the ceramic sample holder 2 is manufactured using ceramic 3D printing technology, and its size and shape can be adjusted according to the size and shape of the sample, with excellent thermal insulation performance and structural stability; the number of groups of the probe assembly can be one group, two groups, three groups, or four groups. When the probe arm bracket 33 is set to two parts separated into left and right, the gap between the two parts together constitutes the groove 332. As Figure 5 As shown, the elastic connector 323 can be a spring. Since the spring is in a pre-compressed state, its elastic force acts upward on the probe arm 32, causing the metal probe 31 to press against the sample surface, directly contacting the contact point on the sample surface (e.g., a platinum-plated film), thereby achieving sample circuit conduction. When the tail end of the probe arm 32 is pressed, the probe arm 32 rotates about the rotating shaft 331 and further compresses the spring, while the metal probe 31 is lifted to separate from the sample. When the tail end of the probe arm 32 is released, the spring rebounds and drives the probe arm 32 to return to its original position.

[0044] In the present invention, the ceramic sample holder 2 is made of a dense ceramic material, which has low thermal conductivity (for example, thermal conductivity is less than 5W / (m·K)) and is an electrical insulator; in some embodiments of the present invention, the ceramic base 41, ceramic shaft 331b, ceramic tube and other ceramic components are also made of a dense ceramic material, which has low thermal conductivity (for example, thermal conductivity is less than 5W / (m·K)) and is an electrical insulator; the base 1, fixed base plate 4, probe arm bracket 33 and other components are made of metal materials, such as stainless steel.

[0045] In some embodiments of the present invention, reference Figures 2-3 The sample portion 21 is a hollow annular structure, with a plurality of vertical limiting columns 211 distributed circumferentially on the top. The gaps between adjacent limiting columns 211 form limiting grooves 212, which can ensure the fixation of the sample while reducing the contact area with the sample, and at the same time ensure the stability of the sample when placed vertically to prevent it from falling off. The number of the limiting columns 211 can be 4 to 8, preferably 6 to 8, and the distances between adjacent limiting columns can be the same or different, so that the contact area between the limiting groove 212 and the silicon carbide wafer X is as small as possible. In some embodiments of the present invention, the heights of the limiting columns 211 are consistent. In some embodiments of the present invention, the limiting columns 211 are irregular in shape. By designing the shape of the limiting columns 211, the fixation of the sample can be achieved on the basis of extremely small contact area with the sample. In some specific embodiments of the present invention, the cross-section of the limiting column 211 is a curved trapezoid, and the shorter bottom side (upper base) of the curved trapezoid is located on the inner ring of the circular ring structure, that is, the longer bottom side (lower base) is located on the outer ring of the circular ring structure. This structure facilitates adjustment of the position of the sample in the limiting groove 212 and can further reduce the contact area between the sample and the ceramic sample holder 2. The silicon carbide sheet X serves as a protective layer in high-temperature electrochemical testing to prevent the sample from being contaminated or damaged during the test. Its excellent thermal conductivity helps to maintain the temperature stability of the test area and ensure the uniformity of the test conditions. The traditional sample preparation method is to load the silicon carbide sheet on a flat metal sample holder. The metal has high thermal conductivity efficiency, a large contact area with the silicon carbide sheet, and the flat metal itself has a large area. These factors lead to low laser heating efficiency, low heating rate and low limit temperature when using this method. The ceramic sample holder 2 of the present invention replaces the function of the flat metal sample holder. By having an extremely small contact area with the silicon carbide sheet X, the heat conducted to the sample holder is reduced. At the same time, the thermal conductivity of the ceramic material is extremely low, which greatly improves the heating efficiency of the sample.

[0046] In some embodiments of the present invention, reference Figures 2-3The fixing part 23 of the ceramic sample holder 2 is two ceramic strips, which are symmetrically fixed on the left and right sides of the sample portion 23. One end of each fixing part 23 is connected to the connecting part 22, and the other end is provided with a vertical ceramic sample holder mounting hole 231 for connecting with the base 1 and the fixed bottom plate 4 through fixing parts such as screws.

[0047] In some embodiments of the present invention, reference Figure 5 The front end of the probe arm 32 is provided with a probe mounting hole 324 for inserting the metal probe 31, and a fastening screw 325 is provided on the side wall thereof for fastening the metal probe 31. Specifically, the fastening screw 325 is screwed into the screw hole on the side wall of the probe arm 32, and the screw hole is perpendicular to the axis of the probe mounting hole 324.

[0048] In some embodiments of the present invention, reference Figure 5 The rotating shaft 331 includes a steel inner core 331a that passes through the probe arm 32 and a ceramic rotating shaft 331b located on both sides of the probe arm 32 and embedded in the side wall of the probe arm bracket 33. The electrical isolation of the probe assembly 3 is achieved through the ceramic rotating shaft 331b.

[0049] In some embodiments of the present invention, reference Figure 5 The rear end of the probe arm 32 is provided with a vertical through hole 321, a screw 322 is installed in the through hole 321, the elastic connector 323 is sleeved on the lower part of the screw 322, and the lower end of the screw 322 is connected to the ceramic base 41 on the fixed bottom plate 4. Figure 5 As shown, the elastic connecting member 323 is a spring, which is in a pre-compressed state in a natural state, and the metal probe 31 is lifted by pressing the tail end of the probe arm 32 .

[0050] In some embodiments of the present invention, reference Figure 1 and Figure 4, a number of mounting holes 42 are coaxially provided on the fixed base plate 4 and the base 1, and the mounting holes 42 correspond to the ceramic rack mounting holes 231; the fixed base plate 4 and the fixing portion 23 of the ceramic sample holder 2 are detachably connected and fixed to the base 1 by fasteners passing through the mounting holes 42 and the ceramic rack mounting holes 231. In some specific embodiments of the present invention, the mounting holes 42 include four screw holes circumferentially distributed on the fixed base plate 4 and the base 1, and the fasteners are countersunk screws 43; at the connection positions at both ends: the countersunk screws 43 pass through the screw holes at both ends of the fixed base plate 4, the ceramic sample holder mounting holes 231 on the fixing portion 23 of the ceramic sample holder, and the screw holes at both ends of the base 1 in sequence and are fixed by nuts; at the middle connection position: the countersunk screws 43 pass through the screw hole in the middle of the fixed base plate 4, the alumina gasket 44, and the screw holes on the base 1 in sequence and are fixed by nuts. An alumina gasket 44 is provided between the fixed base plate 4 and the base 1, with its through hole coaxial with the central screw hole on the fixed base plate 4 and the central screw hole on the base 1, for insulation and heat conduction prevention. Preferably, the countersunk screw 43 is an M1.6 countersunk screw.

[0051] In some embodiments of the present invention, reference Figure 10 The sample holder further includes a connecting gold wire, one end of which is wound around the screw 322 and the other end is connected to the electrical connection terminal 11 on the base 1, thereby achieving electrical connection between the probe assembly 3 and the electrical connection terminal 11. By connecting the gold wire, the metal probe 31 and the electrical connection terminal 11 are connected. When the metal probe 31 directly contacts the contact of the sample, the experimental circuit can be connected. In some preferred embodiments of the present invention, reference Figure 10 The sample holder also includes a ceramic tube, which is sleeved on the outside of the connecting gold wire to prevent short circuit.

[0052] In some embodiments of the present invention, reference Figure 10 The sample holder also includes a standard sample line, which is a gold wire with a flat end, used to provide an experimental reference sample. The flat end of the gold wire can ensure good contact with the instrument, thereby obtaining stable reference data.

[0053] In some embodiments of the present invention, the metal probe 31 is made of platinum-iridium alloy, which has excellent performance in terms of conductivity, chemical inertness, mechanical durability and anti-pollution ability, and can ensure the reliability and repeatability of high-precision surface analysis.

[0054] The second aspect of the present invention provides an in-situ test sample preparation method using the above multi-channel high temperature electrochemical sample holder, referring to Figure 10 , including the following steps:

[0055] Step 1: Place the silicon carbide wafer X in the limiting groove 212 of the ceramic sample holder 2, place a gold mesh of the same size as the silicon carbide wafer on the silicon carbide wafer X, connect the gold mesh to the electrical connection terminal 11 on the base 1 with a gold wire, wrap one end of the connecting gold wire around the screw 322 at the rear end of the probe arm 32, and connect the other end to the electrical connection terminal 11 on the base 1;

[0056] Step 2: Press the tail end of the probe arm 32 to lift the metal probe 31, place the sample on the gold mesh, adjust the position so that the sample falls into the limiting groove 212 of the ceramic sample holder 2, and adjust the position of the metal probe 31 so that the needle tip contacts the contact point of the sample to achieve connection;

[0057] Step 3: Use a multimeter to test whether the electrical connection terminal 11 on the base 1 is insulated from the ground. If it is insulated, proceed to the next step. If it is short-circuited to the ground, check whether the connecting gold wire or fixing screw is in contact with the sample holder;

[0058] Step 4: Use a multimeter to test whether the circuit from the electrical connection terminal 11 on the base 1 to the sample contact is conductive. If it is conductive, the sample preparation is completed. If it is not conductive, it is necessary to check whether the needle tip of the metal probe 31 successfully contacts the sample contact and whether the gold wire connecting the needle tip and the electrical connection terminal 11 on the base 1 is broken.

[0059] After the test is completed, the tail end of the probe arm 32 is pressed to lift the metal probe 31, and the sample is taken out and stored in the sample tray.

[0060] In some embodiments of the present invention, in step three, the fixing screw refers to a fastener that detachably connects the fixed base plate and the base, for example, it can be a countersunk screw 43.

[0061] In some embodiments of the present invention, in step 1, a ceramic tube is placed on the outside of the connecting gold wire to prevent the connecting gold wire from contacting the sample holder and causing a short circuit.

[0062] In some embodiments of the present invention, the Au purity of the gold mesh is greater than 99.99% and the thickness is 0.05 mm to avoid high temperature deformation.

[0063] In some embodiments of the present invention, step 2 further includes moving the sample mark line to the sample surface.

[0064] The traditional welding sample preparation method requires the sample preparer to operate a spot welder and manually press the welded tantalum bar onto the metal support to fix the sample. The welding method is time-consuming and has many limitations. Figure 6 This is a structural photograph of an in-situ XPS test sample obtained using the traditional welding sample preparation method. The silver strips in the picture are tantalum strips. Figure 6The situation does not involve electrochemical connection. If electrochemical connection is required, additional gold wires are required to connect to the contacts, then ceramic sheets are laminated for insulation, and then tantalum bars are laminated and fixed by welding. Such a multi-layered structure is difficult to operate and has a high probability of failure. Even for workers who are skilled in welding and sample preparation, it takes several hours to complete. Figure 7 Schematic diagram of the in-situ XPS test sample structure using traditional welding sample preparation method to achieve electrochemical connection.

[0065] When using a reed to fix the sample, the front edge of the sample contacts the gold foil (to increase the contact area with the sample), one end of the gold wire is connected to the gold foil, and the other end is connected to the electrical connection terminal on the base. An alumina ceramic sheet is placed on the gold foil (isolating the metal reed from the circuit), and then the metal reed is used to press the alumina ceramic sheet at a 45° angle, and the fixing screws are tightened to fix the sample. This also requires multiple layers of stacking, which is complicated to operate. At high temperatures, the reed will experience pressure fluctuations, affecting the fixing effect. Figure 8 Schematic diagram of the in-situ XPS test sample structure using a reed to fix the sample to achieve electrochemical connection. Figure 9 This is a structural photograph of the in-situ XPS test sample obtained using the reed fixation method.

[0066] Figure 10 This image shows an in-situ XPS sample obtained using the multi-channel, high-temperature electrochemical sample holder sample preparation method of the present invention. This method requires only a simple step (place the sample and check the electrochemical connections with a multimeter) to complete sample preparation. A trained operator can complete the process in under five minutes.

[0067] The following is a specific application test example.

[0068] Application Example 1: In-situ Characterization of Valence State Changes in High-Temperature Electrochemical Memristor Channel Materials

[0069] High-temperature in-situ powered APXPS / XAS was used to characterize the changes in the internal electronic structure of LSCF under different working conditions, and the effect of surface modification on the electronic structure of LSCF was studied.

[0070] Sample preparation process: Due to the sample configuration and experimental requirements, the metal probe on the middle probe assembly of the multi-channel high-temperature electrochemical sample holder was removed for this experiment, and the standard sample line was also removed. The silicon carbide wafer was placed in the retaining groove of the ceramic sample holder. A gold mesh of the same size as the silicon carbide wafer was placed on the silicon carbide wafer. The gold mesh was connected to the electrical connection terminal on the base with gold wire. One end of the gold wire was wrapped around the screw at the rear end of the probe arm, and the other end was connected to the electrical connection terminal on the base. Press the tail end of the probe arm to lift the metal probe, and place the thin film sample on the gold mesh so that the metal probe contacts the sample's thin film platinum current collector. Use a multimeter to measure the success of the electrochemical connection, and transfer the sample to the test position in the vacuum chamber through the matching sample transfer system at the bottom of the sample holder.

[0071] Experimental conditions: 5×10 -9 In a mbar vacuum, infrared laser heating achieves a constant temperature of 600°C ± 5°C. Three channels are connected to the electrodes: a Pt / YSZ composite counter electrode, a Pt thin film reference electrode, and an LSCF working electrode. The electronic structures of the Co and Fe elements in the LSCF electrode are monitored.

[0072] Experimental results: Reference Figure 11 , the electronic structure changes of transition metals on the LSCF surface were measured.

[0073] Application Example 2: Conductivity Testing of Rare Earth Oxides at High Temperature

[0074] Sample Preparation: Due to experimental requirements, this experiment expanded the number of test channels to four. A silicon carbide wafer was placed in the retaining groove of the ceramic sample holder. A gold mesh of the same size was placed on the silicon carbide wafer. Gold wire was used to connect the gold mesh to the electrical connection terminals on the base. One end of the gold wire was wrapped around the screw at the rear end of the probe arm, and the other end was connected to the electrical connection terminals on the base. Pressing the end of the probe arm raised the metal probe, and the rare earth oxide thin film sample was placed on the gold mesh, ensuring that the metal probe contacted the sample's thin film platinum current collector. A multimeter was used to measure the electrochemical connection. The sample was then transferred to the test position within the vacuum chamber via a matching sample transfer system at the bottom of the sample holder.

[0075] Experimental conditions: Laser heating to 650°C. 0.1 mbar of oxygen was introduced into the chamber. Bias titration was applied vertically across two electrodes, while electrochemical impedance spectroscopy was measured horizontally across two electrodes. Changes in the surface oxygen valence state were characterized by oxygen electron yield X-ray absorption spectroscopy (O Kedge PEY-XAS).

[0076] Experimental results: Reference Figure 12 , measured the changes in OK edge PEY-XAS under different bias voltages, and successfully demonstrated the influence of changes in the electronic structure of oxygen atoms on the electrical conductivity of the material.

[0077] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A multi-channel high-temperature electrochemical sample holder, characterized in that: It includes a base, a ceramic sample holder and several groups of probe assemblies arranged in sequence from bottom to top; the ceramic sample holder is an integrated structure, including a sample part, a connecting part and a fixing part, the fixing parts are arranged on both sides of the ceramic sample holder and are detachably connected to the base, the sample part is used to carry the sample, and the connecting part integrally connects the sample part and the fixing part; the several groups of probe assemblies are detachably connected to the ceramic sample holder and the base via a fixed base plate; each group of probe assemblies independently includes a metal probe, a probe arm and a probe arm bracket, the metal probe is arranged at the head end of the probe arm, the probe arm bracket is provided with a rotating shaft and a groove for accommodating the probe arm, the probe arm is rotatably connected to the rotating shaft through a rotating shaft hole, the tail end of the probe arm is connected to the fixed base plate through an elastic connecting piece, and the lifting of the metal probe is achieved by pressing the second end of the probe arm.

2. The multi-channel high-temperature electrochemical sample holder according to claim 1, characterized in that: The sample part is a hollow circular structure, with multiple vertical limit columns distributed circumferentially on the top, and the gaps between adjacent limit columns form limit grooves; and / or, the fixing part is two ceramic strips, which are arranged on both sides of the sample part, one end of the ceramic strip is connected to the connecting part, and the other end is provided with a ceramic sample rack mounting hole.

3. The multi-channel high-temperature electrochemical sample holder according to claim 2, characterized in that: The heights of the limiting posts are consistent; and / or the cross-section of the limiting posts is a curved trapezoid, with the shorter base of the curved trapezoid located on the inner ring of the circular structure and the longer base located on the outer ring of the circular structure.

4. The multi-channel high-temperature electrochemical sample holder according to claim 1, characterized in that: The front end face of the probe arm is provided with a probe mounting hole for inserting a metal probe, and the side wall thereof is provided with a fastening screw for fastening the metal probe; and / or, the rotating shaft includes a steel inner core passing through the probe arm and a ceramic rotating shaft located on both sides of the probe arm and embedded in the side walls of the probe arm bracket; and / or, the rear end of the probe arm is provided with a vertical through hole, a screw is installed in the through hole, the elastic connecting piece is sleeved on the lower part of the screw, and the lower end of the screw is connected to the fixed base plate.

5. The multi-channel high-temperature electrochemical sample holder according to claim 2, characterized in that: The fixed base plate and the base are coaxially provided with a plurality of mounting holes, and the mounting holes correspond to the mounting holes of the ceramic sample holder; the fixing portion of the fixed base plate and the ceramic sample holder is detachably connected and fixed to the base by fasteners passing through the mounting holes and the mounting holes of the ceramic sample holder.

6. The multi-channel high-temperature electrochemical sample holder according to claim 5, characterized in that: Four circumferentially distributed screw holes are provided on the fixed base plate and the base, and the fasteners are countersunk screws; at the connection positions at both ends: the countersunk screws sequentially pass through the screw holes at both ends of the fixed base plate, the mounting holes on the fixed part of the ceramic sample holder and the screw holes at both ends of the base and are fixed by nuts; at the middle connection position: the countersunk screws sequentially pass through the screw hole in the middle of the fixed base plate, the alumina gasket and the screw holes on the base and are fixed by nuts.

7. The multi-channel high-temperature electrochemical sample holder according to claim 1, characterized in that: The sample holder further comprises a connecting gold wire, one end of which is wound around the screw, and the other end of which is connected to an electrical connection terminal on the base, thereby achieving conduction between the probe assembly and the electrical connection terminal.

8. The multi-channel high-temperature electrochemical sample holder according to claim 7, characterized in that: The sample holder further comprises a ceramic tube, which is sleeved on the outside of the connecting gold wire to prevent short circuit.

9. The multi-channel high-temperature electrochemical sample holder according to claim 1, characterized in that: The sample holder further includes a sample mark line, the end of which is flat; and / or the metal probe is made of platinum-iridium alloy.

10. A method for preparing samples for in-situ testing using the multi-channel high-temperature electrochemical sample holder according to any one of claims 1 to 8, comprising the following steps: Step 1: Place the silicon carbide wafer in the limiting groove of the ceramic sample holder, place a gold mesh of the same size as the silicon carbide wafer on the silicon carbide wafer, connect the gold mesh to the electrical connection terminal on the base with a gold wire, wrap one end of the gold wire around the screw at the rear end of the probe arm, and connect the other end to the electrical connection terminal on the base; Step 2: Press the tail end of the probe arm to lift the metal probe, place the sample on the gold mesh, adjust the position so that the sample falls into the limit groove of the ceramic sample holder, and adjust the position of the metal probe tip so that the tip touches the contact point of the sample to achieve connection; Step 3: Use a multimeter to test whether the electrical connection terminals on the base are insulated from the ground. If so, proceed to the next step. If short-circuited to the ground, check whether the connecting gold wires or fixing screws are in contact with the sample holder. Step 4: Use a multimeter to test whether the circuit from the electrical connection terminal on the base to the sample contact is conductive. If it is conductive, the sample preparation is complete. If not, it is necessary to check whether the needle tip of the metal probe successfully contacts the sample contact and whether the gold wire connecting the needle tip and the electrical connection terminal on the base is broken.

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