Hydrogen sensitive element, preparation method thereof and hydrogen sensor

Abstract

The invention relates to the technical field of hydrogen sensors, and provides a hydrogen sensitive element, a preparation method thereof and a hydrogen sensor. The hydrogen-sensitive element comprises a carrier, a heating layer, a heat-sensitive layer and a hydrogen-sensitive layer. Wherein a first cavity and a second cavity are formed in the carrier; the heating layer is hermetically arranged in the first cavity; the thermosensitive layer is arranged in the second cavity in a sealing manner; the hydrogen sensitive layer is disposed on the carrier. The hydrogen sensitive element has the characteristics of good thermal stability, high heating efficiency, high response speed and the like.

Description

Technical Field

[0001] The present application relates to the technical field of hydrogen sensors, and in particular to a hydrogen sensitive element, a preparation method thereof, and a hydrogen sensor. Background Art

[0002] Hydrogen sensors are essential components in the process control, monitoring, and analysis of hydrogen energy systems. Palladium alloy hydrogen sensors, in particular, are attracting widespread attention within the industry due to their specific selectivity, high sensitivity, and stability to hydrogen, as well as their excellent chemical and thermal stability.

[0003] Specifically, palladium alloy hydrogen sensors utilize palladium's specific selectivity for hydrogen, enabling precise measurement of hydrogen concentration in complex gas environments. This characteristic is particularly important in areas requiring precise hydrogen measurement and control under complex operating conditions. However, palladium alloys have a large temperature coefficient of resistance, so palladium alloy hydrogen sensors require extremely high operating temperature stability. The solubility of hydrogen in palladium alloy films also varies at different temperatures. For example, low temperatures slow the dissolution of hydrogen in palladium alloys, resulting in decreased sensor sensitivity; excessively high temperatures cause the palladium alloy lattice to expand, reducing hydrogen solubility. Temperature fluctuations can lead to fluctuations in the enthalpy of the hydrogen dissolution process, causing sensor measurement data to shift, reducing accuracy, and deteriorating stability. Therefore, improving the heating stability and reliability of hydrogen sensors is particularly important for accurately detecting hydrogen concentrations under dynamic ambient temperatures. Summary of the Invention

[0004] Based on this, it is necessary to provide a hydrogen sensitive element with stable heating and fast temperature response, a preparation method thereof, and a hydrogen sensor.

[0005] In a first aspect, the present application provides a hydrogen sensitive element, comprising:

[0006] A carrier, wherein a first cavity and a second cavity are provided in the carrier;

[0007] a heating layer, the heating layer being sealed and disposed in the first cavity;

[0008] a heat-sensitive layer, the heat-sensitive layer being sealed in the second cavity; and

[0009] A hydrogen-sensitive layer is disposed on the carrier.

[0010] In some embodiments, the carrier includes a carrier layer and a sealing layer that are stacked together, and the sealing layer is disposed on a surface of the carrier layer that is away from the hydrogen-sensitive layer.

[0011] Optionally, the second cavity is formed between the sealing layer and the carrier layer.

[0012] Optionally, the first cavity is formed in the carrier layer.

[0013] In some embodiments, the sealing layer is made of at least one of glass glaze and silicon nitride.

[0014] In some embodiments, the sealing layer has a thickness of 1 μm to 5 μm.

[0015] In some embodiments, the material of the support layer includes at least one of aluminum oxide, aluminum nitride, silicon carbide, beryllium oxide, boron nitride, and zirconium oxide.

[0016] In some embodiments, the carrier layer has a thickness of 0.5 mm to 2 mm.

[0017] In some embodiments, the material of the hydrogen sensitive layer includes at least one of a palladium-based binary alloy and a palladium-based ternary alloy.

[0018] In some embodiments, the thickness of the hydrogen sensitive layer is 30 nm to 350 nm.

[0019] In some embodiments, the material of the heating layer includes at least one of ruthenium dioxide, nickel-chromium alloy, and tungsten.

[0020] In some embodiments, the thickness of the heating layer is 1 μm to 5 μm.

[0021] In some embodiments, the material of the heat-sensitive layer includes at least one of platinum, cobalt-based oxides, and manganese-based oxides.

[0022] In some embodiments, the thickness of the thermosensitive layer is 1 μm to 3 μm.

[0023] In some embodiments, the hydrogen sensitive element further comprises an activation layer, which is disposed on a surface of the hydrogen sensitive layer away from the carrier, and is used to promote the catalytic rate and hydrogen dissolution rate of the hydrogen sensitive layer.

[0024] In some embodiments, the hydrogen sensitive element further includes a transition layer, and the transition layer is disposed between the hydrogen sensitive layer and the carrier.

[0025] In some embodiments, the material of the activation layer includes at least one of platinum and a ZIF-8 metal framework material.

[0026] In some embodiments, the thickness of the activation layer is 30 nm to 80 nm.

[0027] In some embodiments, the material of the transition layer includes at least one of tantalum oxide, molybdenum oxide, and titanium.

[0028] In some embodiments, the thickness of the transition layer is 60 nm to 300 nm.

[0029] In a second aspect, the present application provides a method for preparing the hydrogen sensitive element as described in the first aspect, the preparation method comprising:

[0030] The first cavity and the second cavity are formed in the material for preparing the carrier, and the heating layer is sealed in the first cavity, and the heat-sensitive layer is sealed in the second cavity, and after sintering, the carrier with the heating layer and the heat-sensitive layer sealed inside is formed;

[0031] The hydrogen-sensitive layer is formed on the carrier to prepare the hydrogen-sensitive element.

[0032] In some embodiments, the carrier includes a carrier layer and a sealing layer, and the method for preparing the carrier includes: placing the heating layer in a material for preparing the carrier layer, and sintering to form the carrier layer with the heating layer sealed therein;

[0033] The heat-sensitive layer is arranged on one side surface of the carrier layer, and the heat-sensitive layer is sealed with the material for preparing the sealing layer. The sealing layer is formed after sintering, and the heat-sensitive layer is sealed between the sealing layer and the carrier layer.

[0034] In some embodiments, the hydrogen sensitive element further includes an activation layer, and the activation layer is formed on a side of the hydrogen sensitive layer away from the carrier by at least one of magnetron sputtering, ion beam sputtering, and evaporation coating.

[0035] In some embodiments, the hydrogen sensitive element further includes a transition layer, and the transition layer is formed on a surface of the carrier close to the hydrogen sensitive layer by at least one of magnetron sputtering, ion beam sputtering, and evaporation coating.

[0036] In a third aspect, the present application provides a hydrogen sensor, which includes the hydrogen sensitive element as described in the first aspect.

[0037] Compared with traditional technologies, this application has at least the following beneficial effects:

[0038] The present application arranges the heating layer and the thermosensitive layer inside the carrier, wherein the heating layer is arranged inside the carrier so that the heat transfer is more direct and effective, greatly improving the heating efficiency, and making the temperature uniformity of the carrier good and the response speed fast. The thermosensitive layer is arranged inside the carrier so that the carrier temperature can be monitored in situ, effectively avoiding the influence of the external ambient temperature, ensuring the accuracy of the temperature regulation of the heating layer, and thus cooperating to improve the temperature stability of the carrier. In addition, the heating layer and the thermosensitive layer are sealed in the carrier to avoid the contact reaction of the ambient gas with the heating layer and the thermosensitive layer, thereby improving the heating stability and detection stability. Therefore, the hydrogen sensitive element of the present application effectively improves the heating efficiency and response speed, and can quickly respond to changes in hydrogen concentration; and in a dynamic temperature environment, the operating temperature balancing speed of the hydrogen sensitive element of the present application is fast, the temperature drift is small, and it can work stably under complex and changeable temperature conditions, greatly improving the overall performance and application range of the hydrogen sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a schematic cross-sectional view of a hydrogen sensitive element provided in one embodiment of the present application;

[0040] Figure 2 This is a schematic structural diagram of one side of the hydrogen-sensitive layer in a hydrogen-sensitive element provided in one embodiment of the present application;

[0041] Figure 3 This is a schematic diagram of the internal structure of a hydrogen sensor provided in one embodiment of the present application;

[0042] Figure 4 This is a schematic diagram of the top surface structure of a hydrogen sensor provided in one embodiment of the present application;

[0043] Figure 5 This is a schematic side structural diagram of a hydrogen sensor provided in one embodiment of the present application;

[0044] Figure 6 This is a schematic structural diagram of a hydrogen sensor testing system provided in one embodiment of the present application;

[0045] Figure 7 This is a graph showing the performance test results of the hydrogen sensor provided in Example 1 of the present application at different concentrations at room temperature and pressure (25°C, 1 atm);

[0046] Figure 8 This is a graph showing the repeatability experimental test results of the hydrogen sensor provided in Example 1 of the present application;

[0047] Figure 9 This is a graph showing the response time test results of the hydrogen sensor provided in Example 1 of the present application in a 1% nitrogen-hydrogen mixture;

[0048] Figure 10This is a graph showing the response time test results of the hydrogen sensor provided in Example 1 of the present application in a 3% nitrogen-hydrogen mixture;

[0049] Figure 11 This is a graph showing the response time test results of the hydrogen sensor provided in Example 1 of the present application in a 5% nitrogen-hydrogen mixture;

[0050] Figure 12 This is a graph showing the performance test results of the hydrogen sensor provided in Example 1 of the present application at different gas pressures;

[0051] Figure 13 This is a performance test result diagram of the hydrogen sensor provided in Example 1 of the present application under the influence of carbon monoxide gas;

[0052] Figure 14 This is a performance test result diagram of the hydrogen sensor provided in Example 1 of the present application under the influence of methane gas.

[0053] Among them, 100-hydrogen sensitive element; 110-carrier; 111-carrier layer; 112-sealing layer; 120-heating layer; 121-heating electrode; 130-thermal sensitive layer; 131-thermal sensitive electrode; 140-hydrogen sensitive layer; 141-hydrogen sensitive electrode; 150-transition layer; 160-activation layer; 200-shell; 210-base; 211-base electrode; 220-cover; 221-air vent; 1-hydrogen cylinder; 2-nitrogen cylinder; 3-gas flowmeter; 4-float flowmeter; 5-hydrogen sensor; 6-data collector. DETAILED DESCRIPTION

[0054] Below in conjunction with embodiment and example, the application is further described in detail These embodiment and example are only used to illustrate the application and are not used to limit the scope of the application, and the purpose of providing these embodiment and example is to make the understanding of the disclosure of the application more thorough and comprehensive. It should also be understood that the application can be implemented in many different forms and is not limited to the embodiment and example described herein. Those skilled in the art can make various changes or modifications without violating the connotation of the application, and the equivalent form obtained also falls within the protection scope of the application. In addition, in the description below, a large amount of specific details are given in order to provide a more complete understanding of the application, and it should be understood that the application can be implemented without one or more of these details.

[0055] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application.

[0056] In this application, the terms "optionally," "optional," and "optional" mean optional or dispensable, i.e., they refer to either option being selected from two parallel options: "with" or "without." If a technical solution contains multiple "optional" clauses, each "optional" clause is independent unless otherwise specified and there are no contradictions or constraints.

[0057] In this application, the terms "first" and "second" in "the first aspect" and "the second aspect" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or quantity, nor should they be understood as implicitly indicating the importance or quantity of the technical features indicated. Furthermore, "first" and "second" serve only as non-exhaustive enumeration and description and should be understood not to constitute a closed-ended limitation on quantity.

[0058] In this application, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0059] In this application, when referring to a numerical interval (i.e., a numerical range), unless otherwise specified, the distribution of the optional numerical values within the numerical interval is deemed to be continuous and includes the two numerical endpoints of the numerical interval (i.e., the minimum and maximum values), as well as each numerical value between the two numerical endpoints. Unless otherwise specified, when a numerical interval refers only to integers within the numerical interval, it includes the two endpoint integers of the numerical range, as well as each integer between the two endpoints, which is equivalent to directly listing each integer. When multiple numerical ranges are provided to describe a feature or characteristic, these numerical ranges can be combined. In other words, unless otherwise specified, the numerical ranges disclosed in this application should be understood to include any and all subranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, percentage, ratio, etc. "Numerical interval" is broadly allowed to include quantitative intervals such as percentage intervals, ratio intervals, and ratio intervals.

[0060] All documents mentioned in this application are cited as references in this application, just as each document is cited as reference separately. Unless they conflict with the application purpose and / or technical solution of this application, the cited documents involved in this application are cited in their entirety and for all purposes. When cited documents are involved in this application, the definitions of relevant technical features, terms, nouns, phrases, etc. in the cited documents are also cited. When cited documents are involved in this application, the examples and preferred embodiments of the cited relevant technical features may also be incorporated into this application as references, but are limited to the ability to implement this application. It should be understood that when the cited content conflicts with the description in this application, the present application shall prevail or be adaptively amended according to the description in this application.

[0061] In traditional technology, the heating layer and hydrogen-sensitive layer in a hydrogen-sensitive element are placed on the same or opposite sides of a carrier. To ensure temperature accuracy at the hydrogen-sensitive layer, the thermal layer and hydrogen-sensitive layer are placed on the same surface of the carrier. However, during the detection process, the heating layer is directly in contact with the environment, causing heat loss, reduced heating efficiency, and slow response. In addition, the thermal layer and heating layer are mostly made of metal materials, which are easily exposed to ambient gases and react with them, affecting the resistance of the thermal layer and heating layer, thereby affecting the measurement accuracy of the thermal layer and the heating accuracy of the heating layer. The hydrogen-sensitive element is prone to temperature drift, which affects the stability of the sensor.

[0062] The first aspect of the present application provides a hydrogen sensitive element, such as Figure 1 As shown, the hydrogen sensitive element 100 includes a carrier 110 , a heating layer 120 , a heat sensitive layer 130 and a hydrogen sensitive layer 140 .

[0063] The carrier 110 is provided with a first cavity and a second cavity; the heating layer 120 is sealed in the first cavity; the heat-sensitive layer 130 is sealed in the second cavity; and the hydrogen-sensitive layer 140 is provided on the carrier 110 .

[0064] The present application arranges the heating layer 120 and the thermosensitive layer 130 inside the carrier 110, wherein the heating layer 120 is arranged inside the carrier 110 so that the heat transfer is more direct and effective, greatly improving the heating efficiency, and making the temperature uniformity of the carrier 110 good and the response speed fast. The thermosensitive layer 130 is arranged inside the carrier 110 to monitor the temperature of the carrier 110 in situ, effectively avoiding the influence of the external ambient temperature, ensuring the accuracy of the temperature regulation of the heating layer 120, and thus cooperating to improve the temperature stability of the carrier 110. In addition, the heating layer 120 and the thermosensitive layer 130 are sealed in the carrier 110, which can avoid the contact reaction of the ambient gas with the heating layer 120 and the thermosensitive layer 130, thereby improving the heating stability and detection stability. Therefore, the hydrogen sensitive element of the present application effectively improves the heating efficiency and response speed, and can quickly respond to changes in hydrogen concentration; and in a dynamic temperature environment, the operating temperature balancing speed of the hydrogen sensitive element 100 of the present application is fast, the temperature drift is small, and it can work stably under complex and variable temperature conditions, greatly improving the overall performance and application range of the hydrogen sensor.

[0065] It is understandable that if Figure 2 As shown, a heating electrode 121, a thermosensitive electrode 131 and a hydrogen-sensitive electrode 141 are provided on the carrier 110 of the present application, wherein the heating electrode 121 is electrically connected to the heating layer 120, the thermosensitive electrode 131 is electrically connected to the thermosensitive layer 130, and the hydrogen-sensitive electrode 141 is electrically connected to the hydrogen-sensitive layer 140.

[0066] It is understood that in this application, the heating layer 120 can realize the heating function; the thermal layer 130 can realize the temperature detection function; and the hydrogen-sensitive layer 140 can realize the hydrogen concentration detection function. In some embodiments, the heating layer 120 is embedded and filled in the first cavity, and the thermal layer 130 is embedded and filled in the second cavity.

[0067] In some embodiments, as Figure 1 As shown, the carrier 110 includes a carrier layer 111 and a sealing layer 112 that are stacked. The sealing layer 112 is disposed on a surface of the carrier layer 111 that is away from the hydrogen-sensitive layer 140. By providing the sealing layer 112, the present application can further improve the airtightness of the carrier 110, inhibiting ambient gas from entering the carrier 110 and reacting with the heating layer 120 and the heat-sensitive layer 130, thereby avoiding temperature drift of the hydrogen-sensitive element 100 due to chemical reactions and improving the temperature stability of the sensor.

[0068] Optionally, the sealing layer 112 may be an insulating sealing layer 112 .

[0069] It is understandable that in the present application, the heating layer 120 and the thermosensitive layer 130 are spaced apart to avoid direct contact between the heating layer 120 and the thermosensitive layer 130 .

[0070] Optionally, the second cavity is formed between the sealing layer 112 and the carrier layer 111 , that is, the heat-sensitive layer 130 is sealed and disposed between the sealing layer 112 and the carrier layer 111 .

[0071] Optionally, the first cavity is formed within the carrier layer 111, that is, the heating layer 120 is sealed within the carrier layer 111. Further optionally, the heating layer 120 and the heat-sensitive layer 130 are disposed in the middle region of the carrier layer 111 in the thickness direction. Even further optionally, the heating layer 120 is centrally disposed within the carrier layer 111.

[0072] In some embodiments, the sealing layer 112 is made of at least one of glass glaze and silicon nitride.

[0073] In some embodiments, the sealing layer 112 has a thickness of 1 μm to 5 μm, for example, 1.0 μm, 1.5 μm, 2.0 μm, 2.5 μm, 3.0 μm, 3.5 μm, 4.0 μm, 4.5 μm or 5.0 μm.

[0074] In some embodiments, the material of the carrier layer 111 includes at least one of aluminum oxide, aluminum nitride, silicon carbide, beryllium oxide, boron nitride, and zirconium oxide.

[0075] In some embodiments, the thickness of the carrier layer 111 is 0.5 mm to 2.0 mm, for example, 0.5 mm, 0.6 mm, 0.8 mm, 1.0 mm, 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm or 2.0 mm.

[0076] In some embodiments, the material of the hydrogen-sensitive layer 140 includes at least one of a palladium-based binary alloy and a palladium-based ternary alloy. For example, the material of the hydrogen-sensitive layer 140 may be a palladium-based ternary alloy, wherein the palladium-based ternary alloy includes, by weight percentage, 83% to 94.9% of Pd (palladium); 5% to 12% of Y (yttrium); and 0.1% to 5% of Ru (ruthenium).

[0077] In some embodiments, the thickness of the hydrogen sensitive layer 140 is 30 nm to 350 nm, for example, 30 nm, 60 nm, 90 nm, 120 nm, 150 nm, 180 nm, 210 nm, 240 nm, 270 nm, 300 nm, 330 nm, or 350 nm.

[0078] In some embodiments, the material of the heating layer 120 includes at least one of ruthenium dioxide, nickel-chromium alloy, and tungsten.

[0079] In some embodiments, the thickness of the heating layer 120 is 1 μm to 5 μm, for example, 1 μm, 2 μm, 3 μm, 4 μm or 5 μm.

[0080] In some embodiments, the material of the heat-sensitive layer 130 includes at least one of platinum, cobalt-based oxides, and manganese-based oxides.

[0081] In some embodiments, the thickness of the heat-sensitive layer 130 is 1 μm to 3 μm, for example, 1.0 μm, 1.5 μm, 2.0 μm, 2.5 μm or 3.0 μm.

[0082] In some embodiments, Figure 1 As shown, the hydrogen sensitive element 100 further includes an activation layer 160, which is disposed on a surface of the hydrogen sensitive layer 140 away from the carrier 110. The activation layer 160 is used to promote the catalytic rate and hydrogen dissolution rate of the hydrogen sensitive layer 140. By disposing the activation layer 160 on the surface of the hydrogen sensitive layer 140, the present application can promote the catalytic rate and hydrogen dissolution rate of hydrogen on the surface of the hydrogen sensitive layer 140, thereby improving the response speed of the hydrogen sensitive element.

[0083] In some embodiments, the hydrogen-sensitive element 100 further includes a transition layer 150, which is disposed between the hydrogen-sensitive layer 140 and the carrier 110. By disposing the transition layer 150 between the carrier 110 and the hydrogen-sensitive layer 140, the present application can effectively repair the surface flatness of the carrier 110 and improve the surface dielectric constant of the carrier 110. Furthermore, the transition layer 150 has a sealing effect and improves the bonding stability of the hydrogen-sensitive layer 140, further preventing gas from entering the carrier 110 and contacting the thermal layer 130 and the heating layer 120.

[0084] In some embodiments, the material of the activation layer 160 includes at least one of platinum and a ZIF-8 metal skeleton material.

[0085] In some embodiments, the thickness of the activation layer 160 is 30 nm to 80 nm, for example, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, or 80 nm.

[0086] In some embodiments, the material of the transition layer 150 includes at least one of tantalum oxide, molybdenum oxide, and titanium.

[0087] In some embodiments, the thickness of the transition layer 150 is 60 nm to 300 nm, for example, 60 nm, 80 nm, 100 nm, 120 nm, 140 nm, 160 nm, 180 nm, 200 nm, 220 nm, 240 nm, 260 nm, 280 nm or 300 nm.

[0088] It should be noted that the heating layer 120, the heat-sensitive layer 130 and the hydrogen-sensitive layer 140 in the hydrogen-sensitive element 100 of the present application can be patterned as required. Figure 2 As shown, the hydrogen sensitive layer 140 may be a reciprocating fold line structure.

[0089] In some embodiments, the hydrogen-sensitive element 100 includes a carrier 110, on one side of which a transition layer 150, a hydrogen-sensitive layer 140, and an activation layer 160 are sequentially disposed in a direction away from the carrier 110. A heating layer 120 and a heat-sensitive layer 130 are sealed within the carrier 110. The carrier 110 includes a carrier layer 111 and a sealing layer 112 stacked in sequence, wherein the carrier layer 111 is in contact with the transition layer 150, and the sealing layer 112 is disposed on a side of the carrier layer 111 away from the transition layer 150. Optionally, the heating layer 120 is sealed within the carrier layer 111, and the heat-sensitive layer 130 is sealed between the sealing layer 112 and the carrier layer 111.

[0090] The second aspect of the present application provides a method for preparing the hydrogen sensitive element as described in the first aspect, the preparation method comprising:

[0091] The first cavity and the second cavity are formed in the material for preparing the carrier 110, and the heating layer 120 is sealed in the first cavity, and the heat-sensitive layer 130 is sealed in the second cavity. After sintering, the carrier 110 with the heating layer 120 and the heat-sensitive layer 130 sealed therein is formed;

[0092] A hydrogen-sensitive layer 140 is formed on the carrier 110 to prepare the hydrogen-sensitive element 100 .

[0093] In some embodiments, the carrier 110 includes a carrier layer 111 and a sealing layer 112. The method for preparing the carrier 110 includes: placing the heating layer 120 in a material for preparing the carrier layer 111, and sintering to form the carrier layer 111 with the heating layer 120 sealed therein;

[0094] The thermosensitive layer 130 is disposed on one side surface of the carrier layer 111 , and the thermosensitive layer 130 is sealed with the material for preparing the sealing layer 112 . The sealing layer 112 is formed after sintering, and the thermosensitive layer 130 is sealed between the sealing layer 112 and the carrier layer 111 .

[0095] The present application adopts a co-sintering method to seal the heating layer 120 and the thermosensitive layer 130 in the carrier 110. The method is simple and has good structural stability, which can effectively improve the heating efficiency and temperature detection accuracy, thereby improving the stability of the hydrogen sensitive element.

[0096] It is understandable that before sintering, a flow port connected to the heating layer 120 and the thermosensitive layer 130 is reserved, and then the electrodes of the heating layer 120 and the thermosensitive layer 130 can be led out by gold paste pouring.

[0097] Optionally, the sintering method adopts a low temperature co-fired ceramic process (LTCC), and the sintering temperature thereof may be 800°C to 950°C, or adopts a high temperature co-fired ceramic process (HTCC), and the sintering temperature thereof may be 1600°C to 1800°C.

[0098] In some embodiments, the hydrogen sensitive element further includes an activation layer 160 , which is formed on a side of the hydrogen sensitive layer 140 away from the carrier 110 by at least one of magnetron sputtering, ion beam sputtering, and evaporation coating.

[0099] In some embodiments, the hydrogen sensitive element further includes a transition layer 150 , which is formed on a surface of the carrier 110 close to the hydrogen sensitive layer 140 by at least one of magnetron sputtering, ion beam sputtering, and evaporation coating.

[0100] The third aspect of the present application provides a hydrogen sensor, such as Figure 3 、 Figure 4 and Figure 5 As shown, the hydrogen sensor includes the hydrogen sensitive element 100 as described in the first aspect, and further includes:

[0101] a housing 200 , wherein the hydrogen sensitive element 100 is disposed in the housing 200 ; and

[0102] Multiple leads, the leads include at least a first lead, a second lead and a third lead, the first lead is electrically connected to the heating layer 120, and the first lead is used to conduct the circuit; the second lead is electrically connected to the thermal layer 130, and the second lead is used to detect the signal of the thermal layer 130; the third lead is connected to the hydrogen sensitive layer 140, and the third lead is used to conduct the detection signal of the hydrogen sensitive layer 140.

[0103] In some embodiments, as Figure 3 and Figure 4 As shown, the housing 200 includes a cover plate 220 and a base 210 that are interlocked. Optionally, the cover plate 220 is provided with a plurality of vent holes 221, and the side of the hydrogen sensitive element 100 having the hydrogen sensitive layer 140 is adjacent to the cover plate 220. The base 210 is provided with a heat insulation plate and a plurality of base electrodes 211. The base electrodes 211 are respectively electrically connected to the heating layer 120, the heat sensitive layer 130, and the hydrogen sensitive layer 140 of the hydrogen sensitive element 100 via leads, thereby achieving circuit conduction and signal transmission.

[0104] In some embodiments, the lead wire may be a gold wire with a wire diameter of not less than 25 μm.

[0105] The embodiments of the present application will be described in detail below with reference to the examples. It should be understood that these examples are intended to illustrate the present application only and are not intended to limit the scope of the present application. The experimental methods for which specific conditions are not specified in the following examples are preferably referred to the guidance provided in the present application, and can also be based on the experimental manuals or conventional conditions in this area, or according to the conditions recommended by the manufacturer, or with reference to experimental methods known in the art.

[0106] Example 1

[0107] This embodiment provides a method for preparing a hydrogen sensitive element, comprising the following steps:

[0108] S1. Place the heating layer 120 in an alumina ceramic material (raw material for the carrier layer 111) and reserve an electrode along the flow port, and co-sinter at 1500°C~1600°C for 12 hours to prepare the carrier layer 111 with the heating layer 120 disposed therein, wherein the thickness of the heating layer 120 is 3μm and the thickness of the carrier layer 111 is 2mm.

[0109] S2. After grinding the surfaces on both sides of the carrier layer 111 prepared in step S1, a thermosensitive layer 130 is set on one side of the carrier layer 111, and is sealed with a glass glaze material (raw material for the sealing layer 112) and an electrode flow port is reserved. Co-sintering is performed at a temperature of 650°C for 15 minutes to prepare the sealing layer 112, and the thermosensitive layer 130 is sealed and set between the sealing layer 112 and the carrier layer 111, wherein the thickness of the sealing layer 112 is 3μm, the thickness of the thermosensitive layer is 1μm, and the material of the thermosensitive layer is platinum.

[0110] S3. Physical vapor deposition is performed on the side of the carrier layer 111 prepared in step S2 away from the sealing layer 112 to form a transition layer 150 with a thickness of 55 nm. The material of the transition layer 150 is tantalum pentoxide.

[0111] S4. A hydrogen-sensitive layer 140 with a thickness of 200 nm is formed on the transition layer 150 prepared in step S3 by magnetron sputtering. The material of the hydrogen-sensitive layer 140 is the same as the hydrogen-sensitive thin film material in Example 1 of CN111118330A.

[0112] S5. Form an activation layer 160 with a thickness of 55 nm on the hydrogen-sensitive layer 140 obtained in step S4 by using a physical vapor deposition method. The material of the activation layer 160 is platinum.

[0113] S6. Using a gold paste pouring method, the electrodes of the heating layer 120 and the electrodes of the heat-sensitive layer 130 are led to the surface of the hydrogen-sensitive element.

[0114] Example 2

[0115] A hydrogen sensor was prepared according to the method of Example 1, except that, in step S1, the thermal layer 130 and the heating layer 120 were directly interposed in the alumina ceramic material and co-sintered to form a carrier layer 111 containing the thermal layer 130 and the heating layer 120. In step S2, the sealing layer 112 was sintered directly on the carrier layer 111 to form the sealing layer 112.

[0116] Example 3

[0117] A hydrogen sensitive element was prepared according to the method of Example 2, except that in step S1, the thermal layer 130 and the heating layer 120 were directly interposed in the alumina ceramic material and co-sintered to form the carrier layer 111 containing the thermal layer 130 and the heating layer 120. Step S2 was not performed.

[0118] Example 4

[0119] A hydrogen sensitive element was prepared according to the method of Example 1, except that step S5 was not performed and the activation layer 160 was not formed on the surface of the hydrogen sensitive layer 140 .

[0120] Comparative Example 1

[0121] This comparative example provides a method for preparing a hydrogen sensitive element, comprising:

[0122] S1. Sintering alumina ceramic material (raw material for the carrier layer 111 ) at 1500° C. to 1600° C. for 12 hours to prepare the carrier layer 111 .

[0123] S2 , after grinding both side surfaces of the carrier layer 111 prepared in step S1 , a heating layer 120 is provided on one side of the carrier layer 111 .

[0124] S3 , forming a transition layer 150 with a thickness of 55 nm by physical vapor deposition on the side of the carrier layer 111 prepared in step S2 away from the heating layer 120 .

[0125] S4. A hydrogen-sensitive layer 140 with a thickness of 200 nm is formed on the transition layer 150 prepared in step S3 by using a physical vapor deposition method, and a heat-sensitive layer 130 is formed on the transition layer 150. The hydrogen-sensitive layer 140 and the heat-sensitive layer 130 are arranged at intervals.

[0126] S5. An activation layer 160 with a thickness of 55 nm is formed on the hydrogen-sensitive layer 140 prepared in step S4 by magnetron sputtering.

[0127] Comparative Example 2

[0128] A hydrogen sensitive element was prepared according to the method of Example 1, except that the heat sensitive layer 130 was formed on the transition layer 150 and was provided on the same layer as the hydrogen sensitive layer 140 .

[0129] The hydrogen sensitive elements prepared in the above examples and comparative examples are assembled into a hydrogen sensor. The assembly method includes:

[0130] The hydrogen sensitive element is mounted on the base 210, and the electrodes of the heating layer 120, the heat-sensitive layer 130 and the hydrogen-sensitive layer 140 in the hydrogen sensitive element are connected to the base electrodes 211 respectively. Then, the cover 220 with the air holes 221 is fastened to the base 210 and sealed by gold-tin welding.

[0131] Install the above hydrogen sensor as follows Figure 6 The performance test is performed in the test system shown, which includes a hydrogen cylinder 1, a nitrogen cylinder 2, a gas flow meter 3, a float flow meter 4, a hydrogen sensor 5 and a data collector 6. The test method includes:

[0132] After a 30-minute preheating period, start the vacuum pump to expel air from the test vessel to a pressure of 10 kPa. Then, inject a 1% standard nitrogen-hydrogen mixture (1% H₂ / 99% N₂ by volume) to a pressure of 101 kPa (normal pressure). Close the standard gas valve. During this process, the hydrogen sensor reading should rise and the sensor resistance should stabilize. Record the measured data. This corresponds to a 1% H₂ concentration by volume.

[0133] Start the vacuum pump to extract the standard hydrogen from the container and inject a second hydrogen concentration for testing and calibration. Repeat this process, starting with 1% hydrogen concentration and calibrating until the desired hydrogen concentration is reached. After obtaining the sensor's unit resistance, a mathematical model is established and input into the secondary data acquisition system.

[0134] In the test system, nitrogen and hydrogen mixed gas was used, and 1%, 3%, 5%, 7%, 10%, 15%, and 20% standard hydrogen were filled in sequence for testing. The results were as follows: Figure 7 The results shown in the figure show clear gradients within each range, sufficient resistance variation, and performance meeting design specifications. Table 1 shows the T90 response time and measurement accuracy at a hydrogen concentration of 3%. Measurement accuracy refers to a 10-minute duration at a 3% hydrogen concentration. Measurement accuracy = (maximum concentration detected - minimum concentration detected) / average hydrogen concentration.

[0135] refer to Figure 8 The sensor was tested for repeatability in nitrogen-hydrogen mixtures with concentrations of 1%, 3%, and 5%, and the repeatability of the test results was within 1.5% FS.

[0136] refer to Figure 9 ,The response time test results of the sensor using 1% nitrogen and hydrogen mixture are shown in the figure, and the response speed is 24s.

[0137] refer to Figure 10 ,The response time test results of the sensor using 3% nitrogen and hydrogen mixture are shown in the figure, and the response speed is 32s.

[0138] refer to Figure 11 ,The response time test results of the sensor using 5% nitrogen and hydrogen mixture are shown in the figure, and the response speed is 32s.

[0139] refer to Figure 12 The sensor has good linearity for 0~25vol.% hydrogen concentration under pressure of 10kPa~800kPa, and the measurement accuracy is within the range of +2% FS.

[0140] refer to Figure 13 , the sensor was tested under normal temperature and pressure with carbon monoxide (CO) gas, and the results showed that the effect was minimal. Figure 14As shown, under normal temperature and pressure, the effect of methane gas on the hydrogen sensor is very small.

[0141] Table 1

[0142]

[0143] From the table above we can see that:

[0144] (1) Comparing Example 1 with Example 3, it can be seen that the present application provides a sealing layer 112, thereby ensuring a stable substrate operating temperature (±0.01°C) in a hydrogen atmosphere for a long time, thereby ensuring measurement accuracy.

[0145] (2) Comparing Example 1 with Example 4, it can be seen that the present application has the advantages of fast sensor response speed, high sensitivity, and fast dehydrogenation by setting the activation layer 160.

[0146] (3) Compared with Comparative Examples 1-2, it can be seen that the present application arranges the heating layer 120 and the thermosensitive layer 130 inside the carrier 110, wherein the heating layer 120 is arranged inside the carrier 110 so that the heat transfer is more direct and effective, greatly improving the heating efficiency, and making the temperature uniformity of the carrier 110 good and the response speed fast. The thermosensitive layer 130 is arranged inside the carrier 110 to monitor the temperature of the carrier 110 in situ, effectively avoiding the influence of the external ambient temperature, ensuring the accuracy of the temperature adjustment of the heating layer 120, and thus cooperating to improve the temperature stability of the carrier 110. In addition, sealing the heating layer 120 and the thermosensitive layer 130 inside the carrier 110 can avoid the contact reaction between the ambient gas and the heating layer 120 and the thermosensitive layer 130, thereby improving the heating stability and detection stability. Therefore, the sensitive element of the present application effectively improves the heating efficiency and response speed, and can quickly respond to changes in hydrogen concentration; and in a dynamic temperature environment, the working temperature balancing speed of the hydrogen sensitive element of the present application is fast, the temperature drift is small, and it can work stably under complex and variable temperature conditions, greatly improving the overall performance and application range of the hydrogen sensor.

[0147] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0148] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and such modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A hydrogen sensitive element, characterized in that: The hydrogen sensitive element comprises: A carrier, wherein a first cavity and a second cavity are provided in the carrier; a heating layer, the heating layer being sealed and disposed in the first cavity; a heat-sensitive layer, the heat-sensitive layer being sealed in the second cavity; and A hydrogen-sensitive layer is disposed on the carrier.

2. The hydrogen sensitive element according to claim 1, wherein The carrier comprises a carrier layer and a sealing layer which are stacked, and the sealing layer is arranged on a surface of the carrier layer which is away from the hydrogen sensitive layer; Optionally, the second cavity is formed between the sealing layer and the carrier layer; Optionally, the first cavity is formed in the carrier layer.

3. The hydrogen sensitive element according to claim 2, wherein: The carrier satisfies at least one of the following conditions: (1) The material of the sealing layer includes at least one of glass glaze and silicon nitride; (2) The thickness of the sealing layer is 1 μm to 5 μm; (3) The material of the carrier layer includes at least one of aluminum oxide, aluminum nitride, silicon carbide, beryllium oxide, boron nitride and zirconium oxide; (4) The thickness of the carrier layer is 0.5 mm to 2.0 mm.

4. The hydrogen sensitive element according to claim 1, wherein The hydrogen sensitive element satisfies at least one of the following conditions: (1) The material of the hydrogen sensitive layer includes at least one of a palladium-based binary alloy and a palladium-based ternary alloy; (2) The thickness of the hydrogen sensitive layer is 30 nm to 350 nm; (3) The material of the heating layer includes at least one of ruthenium dioxide, nickel-chromium alloy and tungsten; (4) The thickness of the heating layer is 1 μm to 5 μm; (5) The material of the heat-sensitive layer includes at least one of platinum, cobalt-based oxides and manganese-based oxides; (6) The thickness of the thermal sensitive layer is 1 μm to 3 μm.

5. The hydrogen sensitive element according to any one of claims 1 to 4, characterized in that: The hydrogen sensitive element also satisfies at least one of the following conditions: (1) The hydrogen sensitive element further comprises an activation layer, which is disposed on a surface of the hydrogen sensitive layer away from the carrier, and is used to promote the catalytic rate and hydrogen dissolution rate of the hydrogen sensitive layer; (2) The hydrogen sensitive element further includes a transition layer, which is arranged between the hydrogen sensitive layer and the carrier.

6. The hydrogen sensitive element according to claim 5, characterized in that: The activation layer satisfies at least one of the following conditions: (1) The material of the activation layer includes at least one of platinum and ZIF-8 metal skeleton material; (2) The thickness of the activation layer is 30 nm to 80 nm.

7. The hydrogen sensitive element according to claim 5, characterized in that: The transition layer satisfies at least one of the following conditions: (1) The material of the transition layer includes at least one of tantalum oxide, molybdenum oxide and titanium; (2) The thickness of the transition layer is 60nm~300nm.

8. A method for preparing a hydrogen sensitive element according to any one of claims 1 to 7, characterized in that: The preparation method comprises: The first cavity and the second cavity are formed in the material for preparing the carrier, and the heating layer is sealed in the first cavity, and the heat-sensitive layer is sealed in the second cavity, and after sintering, the carrier with the heating layer and the heat-sensitive layer sealed inside is formed; The hydrogen-sensitive layer is formed on the carrier to prepare the hydrogen-sensitive element.

9. The method for preparing a hydrogen sensitive element according to claim 8, wherein: The preparation method further satisfies at least one of the following conditions: (1) The carrier includes a carrier layer and a sealing layer. The method for preparing the carrier includes: placing the heating layer in the material for preparing the carrier layer, and sintering to form the carrier layer with the heating layer sealed inside; The heat-sensitive layer is arranged on one side surface of the carrier layer, and the heat-sensitive layer is sealed with the material for preparing the sealing layer, and the sealing layer is formed after sintering, and the heat-sensitive layer is sealed between the sealing layer and the carrier layer; (2) The hydrogen sensitive element further includes an activation layer, and the activation layer is formed on a side of the hydrogen sensitive layer away from the carrier by at least one of magnetron sputtering, ion beam sputtering and evaporation coating; (3) The hydrogen sensitive element further includes a transition layer, which is formed on the surface of the carrier on the side close to the hydrogen sensitive layer by at least one of magnetron sputtering, ion beam sputtering and evaporation coating.

10. A hydrogen sensor, characterized in that: The hydrogen sensor comprises the hydrogen sensitive element according to any one of claims 1 to 7.

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