CN115808460B - Carbon dioxide gas-sensitive material and application thereof, carbon dioxide sensor and preparation method thereof - Google Patents
Carbon dioxide gas-sensitive material and application thereof, carbon dioxide sensor and preparation method thereof Download PDFInfo
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Abstract
The invention relates to a carbon dioxide gas-sensitive material, application thereof, a carbon dioxide sensor and a preparation method thereof, wherein the carbon dioxide gas-sensitive material comprises Na 3+x La x Zr 2‑x Si 2 PO 12 X is more than or equal to 0 and less than or equal to 0.6. The invention adopts Na 3+x La x Zr 2‑x Si 2 PO 12 As a carbon dioxide gas-sensitive material, the sensitivity to carbon dioxide is effectively improved, and the carbon dioxide gas-sensitive material has high conductivity, so that the detection reaction speed of a carbon dioxide sensor is improved, and the detection response time is shortened.
Description
Technical Field
The application relates to the technical field of carbon dioxide detection, in particular to a carbon dioxide gas-sensitive material and application thereof, a carbon dioxide sensor and a preparation method thereof.
Background
Currently, based on the detection of CO 2 The working mechanism of (2) is different, CO can be obtained 2 The sensors are classified into optical sensing type, metal oxide type, electrolyte type, and the like. Which is a kind ofThe optical sensing type gas sensor is used for qualitatively and quantitatively analyzing the concentration of the gas by measuring the infrared absorption condition within the range of 4200-4400 nm; but the equipment is huge, the reading circuit is expensive, and the application of the device in industrialization and large scale is severely restricted. The metal oxide type gas sensor is used for detecting gas by measuring the change condition of the self resistance of the gas sensitive material along with the concentration of the gas; the electrolyte type sensor monitors the concentration of gas mainly by collecting the voltage and current generated by ion reaction.
Although the electrolyte-type gas sensor has relatively small power consumption and high sensitivity, the conductivity of the solid electrolyte also greatly affects the gas-sensitive performance of the electrolyte-type gas sensor. In the actual preparation process, the high-pressure environment and the high annealing temperature have great influence on the diffusion process of solid electrolyte ions, and the poor sintering process tends to improve the grain boundary resistance of the solid electrolyte, thereby affecting the gas-sensitive performance of the gas-sensitive material.
Therefore, how to provide a carbon dioxide gas-sensitive material with high sensitivity, and improve the response speed of a carbon dioxide sensor, is a technical problem that needs to be solved urgently at present.
Disclosure of Invention
Based on this, it is necessary to provide a carbon dioxide gas-sensitive material, a carbon dioxide sensor and a method of manufacturing the same. The application adopts Na 3+x La x Zr 2-x Si 2 PO 12 As a carbon dioxide gas-sensitive material, the sensitivity to carbon dioxide is effectively improved, and the carbon dioxide gas-sensitive material has high conductivity, so that the detection reaction speed of a carbon dioxide sensor is improved, and the detection response time is shortened.
The specific scheme for solving the technical problems is as follows:
in a first aspect, the present application provides a carbon dioxide gas-sensitive material comprising Na 3+ x La x Zr 2-x Si 2 PO 12 0.ltoreq.x.ltoreq.0.6, for example x is 0, 0.1, 0.2, 0.3, 0.4, 0.5 or 0.6.
In one embodiment, the carbon dioxide gas sensitive material is made by a process comprising the steps of:
and mixing and heating a sodium source, a lanthanum source, a zirconium source, a silicon source and a phosphorus source to obtain gel, and calcining the gel to obtain the carbon dioxide gas-sensitive material.
In one embodiment, the sodium source comprises NaNO 3 、NaCO 3 And CH (CH) 3 At least one of COONa.
Optionally, the lanthanum source comprises La (CH 3 COO) 3 、La 2 (CO 3 ) 3 And La (NO) 3 ) 3 ·6H 2 At least one of O.
Optionally, the zirconium source comprises ZrO (CH 3 COO) 2 、ZrO(NO 3 ) 2 ·2H 2 O and Zr (NO) 3 ) 4 At least one of them.
Optionally, the silicon source comprises SiO 2 ·H 2 O and/or Si (OC) 2 H 5 ) 4 。
Optionally, the phosphorus source comprises NH 4 H 2 PO 4 、(NH 4 ) 2 HPO 4 And (NH) 4 ) 3 PO 4 At least one of them.
In one embodiment, the gel is prepared using a chelating agent and a solvent.
Optionally, the preparation process of the gel comprises the following steps: mixing a sodium source, a lanthanum source, a zirconium source, a silicon source, a phosphorus source, water and a chelating agent, and heating at 60-100 ℃, for example, 60 ℃, 65 ℃, 70 ℃, 75 ℃,80 ℃, 85 ℃, 90 ℃, 95 ℃ or 100 ℃ to obtain a raw solution.
Optionally, 5-15% of the sodium source, lanthanum source and zirconium source are added to the original solution in excess, stirring is continued, and then 5-15% of phosphorus source is added in excess to obtain the gel, for example, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14% or 15% of the gel is added in excess.
In one embodiment, the method further comprises, prior to calcining: the gel is subjected to a first drying, at least one washing and a second drying treatment in this order.
Optionally, the temperature of the first drying is 70-80 ℃, for example, 70 ℃, 71 ℃, 72 ℃, 73 ℃, 74 ℃, 75 ℃, 76 ℃, 77 ℃, 78 ℃, 79 ℃ or 80 ℃.
Optionally, the first drying time is 10-12 h, for example, 10.0h, 10.2h, 10.4h, 10.6h, 10.8h, 11.0h, 11.2h, 11.4h, 11.6h, 11.8h or 12.0h.
Optionally, the second drying is constant temperature drying, and the temperature of the constant temperature drying is 80-120 ℃, for example, the temperature is 80 ℃, 85 ℃, 90 ℃, 95 ℃,100 ℃, 105 ℃, 110 ℃, 115 ℃ or 120 ℃, and further optionally, the time of the constant temperature drying is 8-10 h, for example, the time is 8h, 9h or 10h.
In one embodiment, the calcination temperature is 800-900 ℃, e.g., 800 ℃, 810 ℃, 820 ℃, 830 ℃, 840 ℃, 850 ℃, 860 ℃, 870 ℃, 880 ℃, 890 ℃, or 900 ℃.
Optionally, the calcination time is 8-10 hours, for example, 8 hours, 9 hours, or 10 hours.
Optionally, the atmosphere of calcination is an air atmosphere.
In a second aspect, the present application provides the use of a carbon dioxide gas-sensitive material according to the first aspect in a carbon dioxide sensor.
In a third aspect, the present application provides a carbon dioxide sensor comprising a substrate, an electrolyte layer, a reference electrode, and a sensing electrode; the electrolyte layer is arranged on one side surface of the substrate, and the reference electrode and the sensitive electrode are respectively arranged on the surface of the electrolyte layer, which is far away from one side of the substrate; the material of the electrolyte layer comprises the carbon dioxide gas sensitive material according to the first aspect.
In one embodiment, the material of the sensitive electrode comprises Na 2 CO 3 With BaCO 3 Further alternatively, na 2 CO 3 With BaCO 3 The molar ratio of (1.5-1.72), for example, the molar ratio is 1:1.50, 1:1.52, 1:1.54, 1:1.56, 1:1.58, 1:1.60, 1:1.62, 1:1.64, 1:1.66, 1:1.681:1.70 or 1:72.
In one embodiment, the material of the reference electrode comprises Na 2 CO 3 With TiO 2 Na in the reference electrode 2 CO 3 With TiO 2 The molar ratio of (3) to (6) is, for example, 1:3.0, 1:3.3, 1:3.6, 1:3.9, 1:4.2, 1:4.5, 1:4.8, 1:5.1, 1:5.4, 1:5.7 or 1:6.0.
Optionally, the material of the substrate includes Al 2 O 3 。
Optionally, the carbon dioxide sensor further comprises a wire mesh layer for leading out the reference electrode and the sensitive electrode, respectively.
Optionally, the wire mesh layer includes a first wire mesh layer disposed on a surface of the reference electrode remote from the electrolyte layer, and a second wire mesh layer disposed between the sensitive electrode and the electrolyte layer.
Optionally, the metal in the wire mesh layer comprises gold.
In a fourth aspect, the present application provides a method for preparing a carbon dioxide sensor, the method for preparing a carbon dioxide sensor comprising:
applying electrolyte material on one side surface of a substrate to form an electrolyte layer, respectively applying sensitive electrode material and reference electrode material on the surface of the electrolyte layer, and sequentially sintering to form a sensitive electrode and a reference electrode, wherein the sensitive electrode and the reference electrode are both positioned on the surface of the electrolyte layer, which is far away from one side of the substrate;
wherein the electrolyte material comprises a carbon dioxide gas sensitive material as described in the first aspect.
In one embodiment, the sensitive electrode material is made by a method comprising the steps of: na is mixed with 2 CO 3 And BaCO 3 After mixed melting, quench solidifies, optionally Na 2 CO 3 And BaCO 3 The molar ratio of (2) is 1 (1.5-1.72).
Optionally, the melting temperature is 700-800 ℃, for example 700 ℃, 710 ℃, 720 ℃, 730 ℃, 740 ℃, 750 ℃, 760 ℃, 770 ℃, 780 ℃, 790 ℃ or 800 ℃. Further alternatively, the melting time is 20-40 min, for example 20min, 22min, 24min, 26min, 28min, 30min, 32min, 34min, 36min, 38min or 40min.
Optionally, the quench solidification is performed on a brass plate under an air atmosphere.
In one embodiment, the reference electrode material is made by a method comprising the steps of: na is mixed with 2 CO 3 With TiO 2 Grinding and calcining after mixing, optionally Na 2 CO 3 With TiO 2 The molar ratio of (3) to (6) is 1.
Optionally, the number of grinding and calcining is at least two; further alternatively, the milling is performed by ball milling.
Optionally, the calcination temperature is 800-900 ℃, such as 800 ℃, 810 ℃, 820 ℃, 830 ℃, 840 ℃, 850 ℃, 860 ℃, 870 ℃, 880 ℃, 890 ℃ or 900 ℃, and the calcination time is 10-14 h, such as 10h, 11h, 12h, 13h or 14h.
In one embodiment, the step of forming the electrolyte layer includes: the electrolyte material is prepared into slurry, printed on the surface of a substrate, and dried to form an electrolyte layer.
In one embodiment, the reference electrode and the sensing electrode are formed by preparing a sensing electrode material and a reference electrode material into slurry, printing, drying and sintering.
Optionally, the sintering temperature is 500-700 ℃, such as 500 ℃, 520 ℃, 540 ℃, 560 ℃, 580 ℃, 600 ℃, 620 ℃, 640 ℃, 660 ℃, 680 ℃ or 700 ℃, and further optionally, the sintering time is 4-6 h, such as 4.0h, 4.5h, 5.0h, 5.5h or 6.0h.
The invention has the following beneficial effects:
the invention adopts Na 3+x La x Zr 2-x Si 2 PO 12 As carbon dioxide gas sensitive material, NASICON material has Na + Transmission channel for improving the oxidationThe sensitivity of carbon is further increased by doping rare earth metal elements, na + The conductivity is further improved, the gas-sensitive material can be catalyzed, and the sensitivity of the sensor to carbon dioxide is improved.
Drawings
Fig. 1 is a schematic structural view of a carbon dioxide sensor provided in one embodiment of the present application.
FIG. 2 is a graph showing concentration-electromotive force of a carbon dioxide sensor in example 1 of the present invention.
FIG. 3 is a graph showing concentration-response time of the carbon dioxide sensor in example 1 of the present invention.
Wherein, 1-substrate; 2-an electrolyte layer; 3-a reference electrode; 4-sensitive electrodes; 5-a first wire mesh layer; 6-a second wire mesh layer.
Detailed Description
In order that the above objects, features and advantages of the invention will be readily understood, a more particular description of the invention will be rendered by reference to the appended drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. The present invention may be embodied in many other forms than described herein and similarly modified by those skilled in the art without departing from the spirit of the invention, whereby the invention is not limited to the specific embodiments disclosed below.
Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.
It will be understood that when an element is referred to as being "fixed" or "disposed" on another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like are used herein for illustrative purposes only and are not meant to be the only embodiment.
A first aspect of the present application provides a carbon dioxide gas-sensitive material comprising Na 3+x La x Zr 2- x Si 2 PO 12 ，0≤x≤0.6。
The application adopts Na 3+x La x Zr 2-x Si 2 PO 12 Is a NASICON material doped with rare earth elements (La), and the NASICON material is used as a carbon dioxide gas-sensitive material. Wherein the NASICON material has Na + The transmission channel improves the sensitivity of carbon dioxide, and further increases Na by doping rare earth metal elements + The conductivity is further improved, the gas-sensitive material can be catalyzed, and the sensitivity of the sensor to carbon dioxide is improved.
According to the method, the lanthanum element is doped in the gas-sensitive material, the specific lanthanum oxide is formed in the preparation process, and then the specific lanthanum oxide can be combined with the carbon dioxide to form part of the thermodynamically unstable lanthanum carbonate, and then a small amount of carbon dioxide can be released in the use process of the gas-sensitive material, so that the response speed of the sensor to low-concentration carbon dioxide is improved, the response time is shortened, further, the aging treatment is carried out after the use is finished, the carbon dioxide can be combined with the lanthanum oxide rapidly to form the thermodynamically unstable lanthanum carbonate again, and the detection recovery time is shortened.
When La is doped in the gas-sensitive material, the carbon dioxide gas-sensitive material can be prepared by a sol-gel method, and the preparation method comprises the following steps:
and mixing and heating a sodium source, a lanthanum source, a zirconium source, a silicon source and a phosphorus source to obtain gel, and calcining the gel to obtain the carbon dioxide gas-sensitive material.
According to the invention, the carbon dioxide gas-sensitive material is prepared by adopting a sol-gel method, the calcination temperature in the preparation process is reduced, and the problem of high grain boundary resistance of the material caused by high temperature and high pressure is effectively avoided, so that the gas-sensitive performance of the gas-sensitive material is influenced, and the conductivity and the sensitivity of the carbon dioxide gas-sensitive material are improved.
Wherein the sodium source comprises NaNO 3 、Na 2 CO 3 And CH (CH) 3 At least one of COONa. The lanthanum source comprises La (CH) 3 COO) 3 、La 2 (CO 3 ) 3 And La (NO) 3 ) 3 ·6H 2 At least one of O. The zirconium source comprises ZrO (CH) 3 COO) 2 、ZrO(NO 3 ) 2 ·2H 2 O and Zr (NO) 3 ) 4 At least one of them. The silicon source comprises SiO 2 ·H 2 O and/or Si (OC) 2 H 5 ) 4 . The phosphorus source comprises NH 4 H 2 PO 4 、(NH 4 ) 2 HPO 4 And (NH) 4 ) 3 PO 4 At least one of them.
In a preferred embodiment, the gel is prepared by using a chelating agent and a solvent, optionally citric acid as the chelating agent and water or polyvinyl alcohol as the solvent, and specifically comprises: and mixing a sodium source, a lanthanum source, a zirconium source, a silicon source, a phosphorus source, water and a chelating agent, and heating at 60-100 ℃ to obtain an original solution.
Further, in the preparation process of the raw solution, 5-15% of the sodium source, the lanthanum source and the zirconium source are respectively and excessively added into the raw solution, stirring is continued, and then 5-15% of the phosphorus source is excessively added to obtain the gel. The present application regulates the formation of a stable gel state by adding the raw materials in excess.
In a preferred embodiment, the method further comprises, prior to calcination: the gel is subjected to a first drying, at least one washing and a second drying treatment in this order. Wherein the temperature of the first drying is 70-80 ℃ and the time is 10-12 h; and the second drying is constant-temperature drying, wherein the temperature of the constant-temperature drying is 80-120 ℃ and the time is 8-10 h. Optionally, the washing mode comprises washing with deionized water and absolute ethyl alcohol, drying at constant temperature, and cooling to room temperature.
In a preferred embodiment, in the preparation step of the carbon dioxide gas-sensitive material, the calcination temperature is 800-900 ℃, and in the application, the calcination temperature is 800-900 ℃, so that the thermodynamically unstable lanthanum carbonate can be formed, the high sensitivity to low-concentration carbon dioxide can be achieved, if the temperature is lower than 800 ℃, the material is incompletely sintered, the surface of the material is not compact, pores are easy to generate to influence the service life of a device, and if the temperature is higher than 900 ℃, the generated lanthanum oxide is stable in structure and is not easy to combine with carbon dioxide to form unstable lanthanum carbonate. Further alternatively, the calcination time is 8-10 h, and the calcination atmosphere is air atmosphere.
A second aspect of the present application provides the use of the carbon dioxide gas sensitive material in a carbon dioxide sensor.
According to an application of the present application, the carbon dioxide sensor may comprise a solid electrolyte layer comprising the carbon dioxide gas sensitive material of the first aspect of the present application.
According to a third aspect of the present application, there is provided a carbon dioxide sensor, as shown in fig. 1, comprising a substrate 1, an electrolyte layer 2, a reference electrode 3 and a sensitive electrode 4; the electrolyte layer 2 is arranged on one side surface of the substrate 1, and the reference electrode 3 and the sensitive electrode 4 are respectively arranged on the surface of the electrolyte layer 2, which is far away from the side of the substrate 1; the material of the electrolyte layer 2 includes the above-described carbon dioxide gas-sensitive material.
In a preferred embodiment, the material of the sensitive electrode comprises Na 2 CO 3 With BaCO 3 ，Na 2 CO 3 With BaCO 3 The molar ratio of (1.5-1.72); the material of the reference electrode comprises Na 2 CO 3 With TiO 2 ，Na 2 CO 3 With TiO 2 The molar ratio of (3) to (6) is 1; the material of the substrate comprises Al 2 O 3 。
The invention adopts Na 2 CO 3 With BaCO 3 As the sensitive electrode material, baCO was used 3 For Na 2 CO 3 Stabilization is further coordinated with carbon dioxide gas sensitive materials, wherein BaCO 3 The stability of the electrode is improved and the stability of the electrode is also improvedWater resistance of the electrode. In addition, the invention adopts Na 2 CO 3 With TiO 2 Making into Na 2 Ti 6 O 13 As reference electrode, this is because of TiO 2 The chemical structure is stable, wherein the rutile type titanium oxide and the anatase type titanium oxide have good electrochemical activity, and are favorable for ion transportation, so that the response speed to carbon dioxide is improved.
Optionally, the carbon dioxide sensor further includes a wire mesh layer, where the wire mesh layer is used to respectively draw out the reference electrode and the sensitive electrode, and it should be noted that the wire mesh layer may be disposed on any surface of the reference electrode or the sensitive electrode, and may be capable of implementing an electrical signal drawing function, for example, the wire mesh layer is made of gold. Further, as shown in fig. 1, the wire mesh layer includes a first wire mesh layer 5 and a second wire mesh layer 6, the first wire mesh layer 5 is disposed on a surface of the reference electrode 3 away from the electrolyte layer 2, and the second wire mesh layer 6 is disposed between the sensitive electrode 4 and the electrolyte layer 2.
A fourth aspect of the present application provides a method for manufacturing a carbon dioxide sensor, the method for manufacturing a carbon dioxide sensor comprising:
an electrolyte material is arranged on one side surface of a substrate to form an electrolyte layer, a sensitive electrode material and a reference electrode material are respectively arranged on the surface of the electrolyte layer, and are sequentially sintered to form a sensitive electrode and a reference electrode, wherein the sensitive electrode and the reference electrode are both positioned on the surface of the electrolyte layer, which is far away from one side of the substrate; the electrolyte material comprises a carbon dioxide gas sensitive material as described in the first aspect.
According to the invention, the electrolyte layer, the sensitive electrode and the reference electrode are respectively prepared in a sintering mode, so that the thermodynamically unstable lanthanum carbonate is further formed in the carbon dioxide gas-sensitive material, and therefore, the combined device is aged, so that the lanthanum carbonate releases a small amount of carbon dioxide in the use process of the sensor, the response speed of the sensor to low-concentration carbon dioxide is improved, and the response time and the recovery time of the sensor are effectively reduced through the combination and release of the carbon dioxide and the lanthanum oxide.
Optionally, the preparation method of the sensitive electrode material comprises the following steps: na with a molar ratio of 1 (1.5-1.72) 2 CO 3 And BaCO 3 After mixing and melting, quenching and solidifying to obtain a sensitive electrode material; the temperature of the melting process is 700-800 ℃, and the heat preservation time of the melting process is 20-40 min. Further, the quench solidification was performed on a brass plate under an air atmosphere.
Optionally, the preparation method of the reference electrode material comprises the following steps: na with a molar ratio of 1 (3-6) 2 CO 3 With TiO 2 And mixing, grinding and calcining to obtain the reference electrode material, wherein the calcining temperature is 800-900 ℃, and the calcining time is 10-14 h. The number of grinding and calcining is at least two. The grinding mode in the preparation method of the reference electrode material is ball milling.
Optionally, the step of forming the electrolyte layer includes: the electrolyte material is prepared into a solution and printed on the surface of the substrate, and an electrolyte layer is formed after drying.
Optionally, the reference electrode and the sensitive electrode are formed by printing, drying and sintering respectively, wherein the sintering temperature is 500-700 ℃, and the sintering heat preservation time is 4-6 hours.
Optionally, the metal wire mesh layer is formed by screen printing, drying and sintering, wherein the drying temperature is 180-220 ℃, the sintering temperature is 800-900 ℃, and the sintering time is 5-15 min.
In a specific implementation method, the ball milling method is to add ethanol for ball milling for 4-6 hours, and the ball milled product is put in a refrigerator for closed storage for use.
The preparation method of the fourth aspect of the application can prepare the carbon dioxide sensor of the third aspect of the application.
The solvent compositions in the following examples and comparative examples adopt terpineol, butyl carbitol acetate, dibutyl phthalate, ethyl cellulose, span 85, 1, 4-butyrolactone and hydrogenated castor oil in a mass ratio of 60:30:10:6:4:1:0.5, wherein the prepared slurry can meet the requirements of drying, sintering and forming.
Example 1
(1) Gas-sensitive material
Weighing NaNO according to stoichiometric ratio 3 、La(CH 3 COO) 3 、ZrO(CH 3 COO) 2 、SiO 2 ·H 2 O、NH 4 H 2 PO 4 Mixing with deionized water, heating at 80deg.C, stirring, and adding 10% of NaNO under stirring 3 、La(CH 3 COO) 3 、ZrO(CH 3 COO) 2 Finally adding NH 4 H 2 PO 4 Gel is formed, and after three times of washing by deionized water and absolute ethyl alcohol, the gel is dried for 9 hours at the constant temperature of 100 ℃, and calcined for 9 hours at the temperature of 850 ℃ to prepare the carbon dioxide gas-sensitive material Na 3.3 La 0.3 Zr 1.7 Si 2 PO 12 (calculated from the stoichiometric ratio of the batch).
(2) Carbon dioxide sensor
The structure of the carbon dioxide sensor is shown in FIG. 1, wherein the substrate is alumina ceramic, and the electrolyte layer is made of Na 3.3 La 0.3 Zr 1.7 Si 2 PO 12 The sensitive electrode is Na with the molar ratio of 1:1.5 2 CO 3 With BaCO 3 The reference electrode is Na with the molar ratio of 1:6 2 CO 3 With TiO 2 The first wire mesh layer is a gold mesh, and the second wire mesh layer is a gold mesh.
Wherein Na is taken as 2 CO 3 And BaCO 3 Mixing and melting for 30min at 750 ℃, and then carrying out air quenching on the brass plate to obtain a sensitive electrode material;
na is mixed with 2 CO 3 With TiO 2 After mixing, adding ethanol, ball milling and grinding for 5 hours, calcining for 12 hours at 900 ℃, and repeating ball milling and calcining for two times to obtain the reference electrode material.
The preparation method of the carbon dioxide sensor comprises the following steps:
selecting 10mm×12mm rectangular aluminum oxide substrate (ultrasonic cleaning with propanol, ethanol and water respectively), and collecting Na 3.3 La 0.3 Zr 1.7 Si 2 PO 12 And solvent composition to form a slurryScreen printing to the surface of an alumina substrate, and drying to form an electrolyte layer;
preparing a reference electrode material and a solvent composition into slurry by screen printing on the surface of an electrolyte layer, drying at 200 ℃, and sintering at 600 ℃ for 5 hours to form a reference electrode;
and (3) screen printing Jin Jiangliao on the surfaces of the reference electrode and the electrolyte lamination respectively, drying at 200 ℃, heating to 850 ℃, and sintering to form a first wire mesh layer and a second wire mesh layer respectively.
And preparing slurry by screen printing a sensitive electrode and a solvent composition in the area of the electrolyte layer with the second screen metal layer, drying at 200 ℃, and then heating to 600 ℃ to sinter for 5 hours to form the sensitive electrode.
Thereby preparing the carbon dioxide sensor.
Example 2
(1) Gas-sensitive material
Weighing NaCO according to stoichiometric ratio 3 、La(CO 3 ) 3 、ZrO(CH 3 COO) 2 、Si(OC 2 H 5 ) 4 、NH 4 H 2 PO 4 Mixing with deionized water, heating at 100deg.C, stirring, and adding 15% of NaCO under stirring 3 、La(CO 3 ) 3 、ZrO(CH 3 COO) 2 And adding NH 4 H 2 PO 4 Gel is formed, after three times of washing by deionized water and absolute ethyl alcohol, the gel is dried for 8 hours at the constant temperature of 120 ℃, and calcined for 10 hours at the temperature of 800 ℃ to prepare the carbon dioxide gas-sensitive material Na 3.1 La 0.1 Zr 1.9 Si 2 PO 12 。
(2) Carbon dioxide sensor
The structure of the carbon dioxide sensor is shown in FIG. 1, wherein the substrate is alumina ceramic, and the electrolyte layer is made of Na 3.1 La 0.1 Zr 1.9 Si 2 PO 12 The sensitive electrode is Na with the mol ratio of 1:1.72 2 CO 3 With BaCO 3 The reference electrode is Na with the molar ratio of 1:6 2 CO 3 With TiO 2 The first wire mesh layer is a gold mesh, and the second wire mesh layer is a gold mesh.
Wherein Na is taken as 2 CO 3 And BaCO 3 Mixing and melting for 40min at 700 ℃, and then carrying out air quenching on a brass plate to obtain a sensitive electrode material;
na is mixed with 2 CO 3 With TiO 2 After mixing, adding ethanol, ball milling and grinding for 5 hours, calcining for 14 hours at 800 ℃, and repeating ball milling and calcining for three times to obtain the reference electrode material.
The preparation method of the carbon dioxide sensor comprises the following steps:
selecting 10mm×12mm rectangular aluminum oxide substrate (ultrasonic cleaning with propanol, ethanol and water respectively), and collecting Na 3.1 La 0.1 Zr 1.9 Si 2 PO 12 Preparing slurry from the solvent composition, screen printing the slurry onto the surface of an alumina substrate, and drying the slurry to form an electrolyte layer;
preparing a reference electrode material and a solvent composition into slurry by screen printing on the surface of an electrolyte layer, drying at 180 ℃, and sintering for 6 hours at 500 ℃ to form a reference electrode;
and (3) screen printing Jin Jiangliao on the surfaces of the reference electrode and the electrolyte lamination respectively, drying at 220 ℃, heating to 800 ℃, and sintering to form a first wire mesh layer and a second wire mesh layer respectively.
And preparing slurry by screen printing a sensitive electrode and a solvent composition in the area of the electrolyte layer with the second screen metal layer, drying at 210 ℃, heating to 700 ℃, and sintering for 4 hours to form the sensitive electrode.
Thereby preparing the carbon dioxide sensor.
Example 3
(1) Gas-sensitive material
Weighing CH according to stoichiometric ratio 3 COONa、La(CH 3 COO) 3 、ZrO(CH 3 COO) 2 、SiO 2 ·H 2 O、NH 4 H 2 PO 4 Mixing with deionized water, heating at 60deg.C, stirring, and stirring to stoichiometric ratioAdding 5% of CH 3 COONa、La(CH 3 COO) 3 、ZrO(CH 3 COO) 2 And adding NH 4 H 2 PO 4 Gel is formed, and after three times of washing by deionized water and absolute ethyl alcohol, the gel is dried for 10 hours at the constant temperature of 80 ℃, and calcined for 8 hours at the temperature of 900 ℃ to prepare the carbon dioxide gas-sensitive material Na 3.6 La 0.6 Zr 1.4 Si 2 PO 12 。
(2) Carbon dioxide sensor
The structure of the carbon dioxide sensor is shown in FIG. 1, wherein the substrate is alumina ceramic, and the electrolyte layer is made of Na 3.6 La 0.6 Zr 1.4 Si 2 PO 12 The sensitive electrode is Na with the molar ratio of 1:1.6 2 CO 3 With BaCO 3 The reference electrode is Na with the molar ratio of 1:6 2 CO 3 With TiO 2 The first wire mesh layer is a gold mesh, and the second wire mesh layer is a gold mesh.
Wherein Na is taken as 2 CO 3 And BaCO 3 Mixing and melting for 20min at 800 ℃, and then carrying out air quenching on the brass plate to obtain a sensitive electrode material;
na is mixed with 2 CO 3 With TiO 2 After mixing, adding ethanol, ball milling and grinding for 5 hours, calcining for 10 hours at 900 ℃, and repeating ball milling and calcining for three times to obtain the reference electrode material.
The preparation method of the carbon dioxide sensor comprises the following steps:
selecting 10mm×12mm rectangular aluminum oxide substrate (ultrasonic cleaning with propanol, ethanol and water respectively), and collecting Na 3.6 La 0.6 Zr 1.4 Si 2 PO 12 Preparing slurry from the solvent composition, screen printing the slurry onto the surface of an alumina substrate, and drying the slurry to form an electrolyte layer;
preparing a reference electrode material and a solvent composition into slurry by screen printing on the surface of an electrolyte layer, drying at 220 ℃, and sintering for 4 hours at 700 ℃ to form a reference electrode;
and (3) screen printing Jin Jiangliao on the surfaces of the reference electrode and the electrolyte lamination respectively, drying at 180 ℃, heating to 900 ℃ and sintering to form a first wire mesh layer and a second wire mesh layer respectively.
And preparing slurry by screen printing a sensitive electrode and a solvent composition in the area of the electrolyte layer with the second screen metal layer, drying at 200 ℃, and then heating to 500 ℃ to sinter for 6 hours to form the sensitive electrode.
Thereby preparing the carbon dioxide sensor.
Example 4
This example provides a carbon dioxide gas-sensitive material, which is different from example 1 in that the carbon dioxide gas-sensitive material is Na 3 Zr 2 Si 2 PO 12 The lanthanum element is not doped in the preparation process, and the preparation process parameters are the same as those of the embodiment 1.
The embodiment also provides a carbon dioxide sensor, wherein the material of the electrolyte layer in the carbon dioxide sensor is Na 3 Zr 2 Si 2 PO 12 The rest of the composition and structure are exactly the same as in example 1.
Example 5
The present embodiment provides a carbon dioxide gas-sensitive material, which is different from embodiment 1 in that the carbon dioxide gas-sensitive material is Na 3.3 Ho 0.3 Zr 1.7 Si 2 PO 12 The Ho element is doped in the preparation process, and the preparation process parameters are the same as those of the embodiment 1.
The embodiment also provides a carbon dioxide sensor, wherein the material of the electrolyte layer in the carbon dioxide sensor is Na 3.3 Ho 0.3 Zr 1.7 Si 2 PO 12 The rest of the composition and structure are exactly the same as in example 1.
Example 6
The present embodiment provides a carbon dioxide sensor, which is different from the carbon dioxide sensor of embodiment 1 in that the material of the sensing electrode is Na only 2 CO 3 The rest of the composition and structure are exactly the same as in example 1.
Example 7
The embodiment provides a carbon dioxide sensor and a real sensorThe carbon dioxide sensor of example 1 differs from the carbon dioxide sensor in that the reference electrode is made of only Na 2 CO 3 The rest of the composition and structure are exactly the same as in example 1.
Example 8
The present embodiment provides a carbon dioxide sensitive material, which is different from embodiment 1 in that in the preparation method of the carbon dioxide sensitive material, the calcination temperature is 1000 ℃, and the other parameters and steps are identical to those of embodiment 1.
The present embodiment also provides a carbon dioxide sensor, and compared with embodiment 1, the material of the electrolyte layer adopts the carbon dioxide gas-sensitive material, and the rest structure and composition are identical to those of embodiment 1.
Example 9
The present embodiment provides a carbon dioxide sensitive material, which is different from embodiment 1 in that in the preparation method of the carbon dioxide sensitive material, the calcination temperature is 700 ℃, and the other parameters and steps are identical to those of embodiment 1.
The present embodiment also provides a carbon dioxide sensor, and compared with embodiment 1, the material of the electrolyte layer adopts the carbon dioxide gas-sensitive material, and the rest structure and composition are identical to those of embodiment 1.
Example 10
The embodiment provides a carbon dioxide sensitive material, which is different from embodiment 1 in that in the preparation method of the carbon dioxide sensitive material, lanthanum nitrate is used as a lanthanum source, and the rest parameters and steps are identical to those of embodiment 1.
The present embodiment also provides a carbon dioxide sensor, and compared with embodiment 1, the material of the electrolyte layer adopts the carbon dioxide gas-sensitive material, and the rest structure and composition are identical to those of embodiment 1.
Comparative example 1
The present comparative example provides a carbon dioxide sensor, which is different from the carbon dioxide sensor of example 1 in that the electrolyte layer of the carbon dioxide sensor is made of LaF 3 The rest of the structure and material are the same as those of the embodiment 1。
Comparative example 2
The present comparative example provides a carbon dioxide sensor, which is different from example 1 in that the electrolyte layer of the carbon dioxide sensor is made of Na 3.3 Ni 0.3 Zr 1.7 Si 2 PO 12 The rest of the structure and materials are exactly the same as those of example 1.
Concentration response time detection and recovery time detection were performed using the carbon dioxide sensors in the above examples and comparative examples:
the response time detection method comprises the following steps: at 500 ℃, gas with the carbon dioxide volume concentration of 1.0% is introduced into the carbon dioxide sensor, the interval time required for the voltage change of the carbon dioxide sensor to appear on the upper platform is measured, namely the response time of the carbon dioxide volume concentration of 1.0% at 500 ℃, and the test results are shown in table 1.
The recovery time detection method comprises the following steps: after stopping the introduction of carbon dioxide gas at 500 c, the interval time required for the response curve to drop and appear on the lower plateau (i.e., the response curve appears on a horizontal straight line) was detected, and the test results are shown in table 1.
Further, the carbon dioxide sensor in example 1 was subjected to sensitivity detection of different carbon dioxide concentrations at 500 ℃ respectively, and the detection method includes: and respectively detecting the condition that the volume concentration of the carbon dioxide is 0% -10.0% at 500 ℃, measuring the electromotive force of the carbon dioxide sensor, and the test result is shown in figure 2.
The response time detection of the carbon dioxide sensor in the embodiment 1, in which the carbon dioxide volume concentration is 0-2.0%, is performed by the following steps: and respectively detecting the condition that the volume concentration of the carbon dioxide is 0-2.0% at 500 ℃, measuring the response time of the carbon dioxide sensor, and the test result is shown in figure 3.
TABLE 1
From the above table, it can be seen that:
(1) Inventive examples 1 and 4-5As compared with comparative examples 1-2, it can be seen that the test results of example 1 are superior to those of examples 4-5 and comparative examples 1-2, and that Na is used in the present invention 3+x La x Zr 2-x Si 2 PO 12 As an electrolyte layer in a carbon dioxide sensor, na is increased + The transmission channel of the carbon dioxide sensor is used for improving the conductivity, further, the gas-sensitive material can be catalyzed by adopting the doping of rare earth elements, the sensitivity of the sensor to carbon dioxide is improved, and by combining with fig. 2 and 3, the response speed of the carbon dioxide sensor is high, the response time of detection is effectively reduced, and the response time can be less than 25s within the preferred range of the invention.
(2) Compared with the embodiment 6-7, the embodiment 1 of the invention has the advantages that the test result of the embodiment 1 is superior to the embodiment 6-7, and the electrode stability can be improved by adopting the specific sensitive electrode material and the reference electrode material, and the effect of improving the response speed and the recovery speed of the device is achieved.
(3) Compared with the embodiment 8-9, the test result of the embodiment 1 is superior to the embodiment 8-9, the temperature of the electrolyte material is controlled to be 800-900 ℃ in the preparation process, the problem that the grain boundary resistance of the solid electrolyte is improved under the high-temperature and high-pressure preparation condition is effectively avoided, so that the gas sensitivity performance of the gas sensitive material is affected, the prepared lanthanum oxide can be combined with carbon dioxide to form the lanthanum carbonate with unstable thermodynamics, the response time and the recovery time of the sensor are improved, if the temperature is lower than 800 ℃, the sintering of the material is incomplete, the surface of the material is not compact, the service life of a device is easily affected, and if the temperature is higher than 900 ℃, the generated lanthanum oxide is stable in structure and is not easy to combine with the carbon dioxide to form the unstable lanthanum carbonate.
(4) Compared with the embodiment 10, the test result of the embodiment 1 is superior to the embodiment 10, and the method controls the raw materials which do not contain difficult elements to remove, so that element residues are avoided in the preparation process of the gas-sensitive material at 800-900 ℃, interference of other impurity ions is avoided, and the sensitivity of the gas-sensitive material to carbon dioxide is influenced.
The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.
The above examples illustrate only a few embodiments of the invention, which are described in detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. The scope of the invention is therefore intended to be covered by the appended claims, and the description and drawings may be interpreted in accordance with the contents of the claims.
Claims (9)
1. A carbon dioxide gas-sensitive material, characterized in that the carbon dioxide gas-sensitive material comprises Na 3+x La x Zr 2- x Si 2 PO 12 ，0≤x≤0.6；
The carbon dioxide gas-sensitive material is prepared by a method comprising the following steps of:
and mixing and heating a sodium source, a lanthanum source, a zirconium source, a silicon source and a phosphorus source to obtain gel, and calcining the gel to obtain the carbon dioxide gas-sensitive material, wherein the calcining temperature is 800-900 ℃, the carbon dioxide gas-sensitive material comprises lanthanum oxide formed by calcining, and the lanthanum oxide formed by calcining can be combined with carbon dioxide to form thermodynamically unstable lanthanum carbonate.
2. The carbon dioxide gas-sensitive material according to claim 1, wherein the calcination time is 8 to 10 hours, and the calcination atmosphere is an air atmosphere.
3. The carbon dioxide gas-sensitive material of claim 2, wherein the gel is prepared by a process comprising: mixing a sodium source, a lanthanum source, a zirconium source, a silicon source, a phosphorus source, water and a chelating agent, heating at 60-100 ℃ to obtain an original solution, respectively adding 5-15% of the sodium source, the lanthanum source and the zirconium source into the original solution in excess, continuously stirring, and then adding 5-15% of the phosphorus source into excess to obtain the gel.
4. Use of the carbon dioxide gas-sensitive material according to any one of claims 1 to 3 in a carbon dioxide sensor.
5. A carbon dioxide sensor, characterized in that the carbon dioxide sensor comprises a substrate, an electrolyte layer, a reference electrode and a sensitive electrode;
the electrolyte layer is arranged on one side surface of the substrate, and the reference electrode and the sensitive electrode are respectively arranged on the surface of the electrolyte layer, which is far away from one side of the substrate;
the material of the electrolyte layer comprises the carbon dioxide gas-sensitive material according to any one of claims 1 to 3.
6. The carbon dioxide sensor of claim 5, wherein the material of the sensing electrode comprises Na 2 CO 3 With BaCO 3 ，Na 2 CO 3 With BaCO 3 The molar ratio of (1.5-1.72);
the material of the reference electrode comprises Na 2 CO 3 With TiO 2 Na in the reference electrode 2 CO 3 With TiO 2 The molar ratio of (3) to (6) is 1;
the carbon dioxide sensor further comprises a wire mesh layer, wherein the wire mesh layer is used for leading out the reference electrode and the sensitive electrode respectively.
7. A method for manufacturing a carbon dioxide sensor, comprising:
applying electrolyte material on one side surface of a substrate to form an electrolyte layer, respectively applying sensitive electrode material and reference electrode material on the surface of the electrolyte layer, and sequentially sintering to form a sensitive electrode and a reference electrode, wherein the sensitive electrode and the reference electrode are both positioned on the surface of the electrolyte layer, which is far away from one side of the substrate;
wherein the electrolyte material comprises the carbon dioxide gas-sensitive material according to any one of claims 1 to 3.
8. The method for manufacturing a carbon dioxide sensor according to claim 7, wherein the sensitive electrode material is manufactured by a method comprising the steps of: na with a molar ratio of 1 (1.5-1.72) 2 CO 3 And BaCO 3 Quenching and solidifying after mixing and melting;
the reference electrode material is prepared by a method comprising the steps of: na with a molar ratio of 1 (3-6) 2 CO 3 With TiO 2 And (5) grinding and calcining after mixing.
9. The method of manufacturing a carbon dioxide sensor according to claim 8, wherein the step of forming the electrolyte layer comprises: preparing an electrolyte material into slurry, printing the slurry on the surface of a substrate, and drying the slurry to form an electrolyte layer;
the reference electrode and the sensitive electrode are formed by respectively preparing a sensitive electrode material and a reference electrode material into slurry, printing, drying and sintering.
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