Electrode material, preparation method thereof, sensor and application

Abstract

The invention provides an electrode material and a preparation method thereof, a sensor and application, the electrode material comprises an electrolyte substrate and a porous skeleton layer arranged on any surface of the electrolyte substrate; the electrolyte substrate comprises a solid electrolyte, and the density of the electrolyte substrate is 5.4-5.5 g / cm < 3 >; the porous skeleton layer comprises an electrolyte skeleton structure and strontium molybdate particles coating at least part of the surface of the electrolyte skeleton structure, and the porosity of the porous skeleton layer is 20-30%; the solid electrolyte is La < 10 > Si < 5.5 > Al < 0.5 > O < 27 >; the electrode material disclosed by the invention has a relatively wide detection range on SO2, the detection range can reach 20-700ppm, the response / recovery speed is increased, and the electrode material has good long-term stability.

Description

Technical Field

[0001] The present invention belongs to the technical field of gas sulfur oxide detection, and in particular relates to an electrode material and a preparation method thereof, a sensor and applications. Background Art

[0002] The steel industry is a vital pillar in building a modern and powerful nation, and sintering is an essential component. During the sintering process, the waste gas, known as sintering flue gas, is subjected to high temperatures and is affected by the sulfur content in the iron ore, resulting in a wide range of SO2 concentrations, from 0 to 1000 ppm. Long-term exposure to low concentrations of SO2 can lead to various illnesses and sensory impairment. Furthermore, the absorption of SO2 from the air by rain or snow contributes to the formation of acid rain, which accelerates the corrosion of buildings and causes soil acidification, making it one of the ten major environmental threats to human survival.

[0003] Traditional SO2 gas analysis technologies, such as gas chromatography, ultraviolet fluorescence, and spectral absorption, have the ability to reliably detect and identify trace gases. However, due to the bulky and expensive equipment and the inability to perform in-situ monitoring, they are unable to meet the needs of real-time monitoring in industrial sites. In contrast, solid electrolyte gas sensors, due to their simple structure, low cost, and fast response, have become an ideal choice for gas monitoring in high-temperature environments. However, existing technologies still face many bottlenecks. For example, the sensor's detection range is relatively narrow, far from meeting the monitoring needs of a wide concentration range of industrial flue gas. At the same time, existing sensors generally have problems such as poor long-term stability and slow response speed in high-temperature corrosive environments, which seriously restricts their practical application.

[0004] Therefore, the development of high-performance SO2 gas sensors that can continuously, online, and in-situ monitor SO2 concentration in the above-mentioned high-temperature exhaust gas environment is of great significance in the fields of industrial and environmental safety, SO2 monitoring and control, etc. Summary of the Invention

[0005] The present invention provides an electrode material and a preparation method thereof, a sensor and applications thereof, which are used to solve the problems of narrow detection range, poor long-term stability, slow response speed and the like of sensors in the prior art.

[0006] In a first aspect, the present invention provides an electrode material comprising an electrolyte substrate and a porous skeleton layer disposed on any surface of the electrolyte substrate;

[0007] The electrolyte substrate includes a solid electrolyte, and the density of the electrolyte substrate is 5.4 to 5.5 g / cm 3 ;

[0008] The porous skeleton layer includes an electrolyte skeleton structure and strontium molybdate particles coated on at least a portion of the surface of the electrolyte skeleton structure, and the porosity of the porous skeleton layer is 20-30%.

[0009] The solid electrolyte is La 10 Si 5.5 Al 0.5 O 27 .

[0010] Compared with the prior art, the present invention is beneficial in that: the dense electrolyte substrate ensures ion selective conduction, the porous skeleton layer provides sufficient reaction interface, the surface of the porous skeleton layer is coated with the sensitive material strontium molybdate (SrMoO4), and the double-layer structure, strontium molybdate and LASO (La 10 Si 5.5 Al 0.5 O 27 ) The synergistic effect of the solid electrolyte enables the electrode material of the present invention to have a relatively wide detection range for SO2, which can reach 20 to 700 ppm, and improves the response / recovery speed and has good long-term stability.

[0011] Furthermore, the thickness of the electrolyte substrate is 1.2 to 1.3 mm; and / or,

[0012] The thickness of the porous skeleton layer is 10 to 15 μm; and / or,

[0013] The electrode loading rate of the electrode material is 10 to 30%.

[0014] In a second aspect, the present invention provides a method for preparing the electrode material according to the first aspect, comprising the following steps:

[0015] S1, performing a first ball milling process and a pre-sintering process on an electrolyte raw material system including La2O3 powder, Al2O3 powder and SiO2 powder to obtain electrolyte powder;

[0016] S2, adding a binder to the electrolyte powder and mixing, and sequentially performing a second ball milling process, a tableting process, and a densification sintering process to obtain an electrolyte substrate;

[0017] S3, adding a pore-forming agent to the electrolyte powder and performing wet grinding and mixing to obtain a pore-forming powder;

[0018] After the pore-forming powder is dried, an organic carrier is added and mixed to obtain a slurry;

[0019] The slurry is coated on any surface of the electrolyte substrate and then subjected to a first calcination treatment to form an electrolyte skeleton structure on the surface of the electrolyte substrate to obtain a double-layer electrolyte material;

[0020] S4, alternately impregnating the electrolyte skeleton structure with two impregnation solutions, a strontium source solution and a molybdenum source solution, and then performing a second calcination treatment to in-situ generate strontium molybdate particles on at least a portion of the surface of the electrolyte skeleton structure to obtain an electrode material;

[0021] The strontium source solution and the molybdenum source solution further contain a complexing agent and a surface wetting agent respectively.

[0022] Further, the adhesive includes at least one of PVB or PVA; and / or,

[0023] The pore-forming agent includes at least one of graphite powder, starch or acetylene black; and / or,

[0024] The organic vehicle comprises 94 wt% terpineol and 6 wt% ethyl cellulose; and / or,

[0025] The strontium source in the strontium source solution is Sr(NO3)2; and / or,

[0026] The molybdenum source in the molybdenum source solution is (NH4)2MoO4; and / or,

[0027] The complexing agent is citric acid; and / or,

[0028] The surface wetting agent is anhydrous ethanol.

[0029] Furthermore, in S1, the pre-sintering temperature is 1295-1305° C. and the time is 11.5-12.5 h; and / or,

[0030] In S2, the temperature of the densification sintering treatment is 1540-1560° C. and the time is 5.5-6.5 h; and / or,

[0031] In S3, the temperature of the first calcination treatment is 1440-1460° C. and the time is 2.8-3.2 h; and / or,

[0032] In S4, the second calcination treatment is performed at a temperature of 895 to 905° C. for a time of 2.8 to 3.2 hours in an air atmosphere.

[0033] Furthermore, in S2, the amount of the binder added is 1.4 to 1.6 wt % of the electrolyte powder; and / or,

[0034] In S3, the amount of the pore-forming agent added is 28 to 32 wt% of the electrolyte powder; and / or,

[0035] In S3, the mass ratio of the pore-forming powder to the organic carrier is 3:7; and / or,

[0036] In S4, the molar concentration of the strontium source in the strontium source solution is 0.05M, the molar concentration of the molybdenum source in the molybdenum source solution is 0.05M, the ratio of the total amount of metal substances in the two impregnation solutions to the amount of citric acid is 1:1, and the molar concentration ratio of the strontium source to the molybdenum source is 1:1.

[0037] Furthermore, the alternating immersion treatment in S2 includes the following steps: using a 10 μL microinjector to immerse the strontium source solution into the electrolyte skeleton structure, and then immersing an equal amount of molybdenum source solution into the electrolyte skeleton structure after natural drying, and alternating immersion for 1-3 times.

[0038] Furthermore, before S1, the La2O3 powder was calcined at 900°C for 3 hours to remove impurities; the Al2O3 powder and the SiO2 powder were dried at 120°C in a vacuum environment for 24 hours.

[0039] In a third aspect, the present invention provides a sensor comprising the electrode material described in the first aspect or the electrode material prepared by the preparation method of the electrode material described in the second aspect.

[0040] In a fourth aspect, the present invention provides an application of the sensor described in the third aspect in SO2 detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 A schematic structural diagram of the sensor provided by the present invention;

[0042] Figure 2 This is the response recovery curve of the sensor provided in Example 2 of the present invention at 350-550°C;

[0043] Figure 3 The relationship between the sensor θ response change value and the logarithm of SO2 concentration provided in Example 2 of the present invention;

[0044] Figure 4 The anti-interference performance of the sensor provided in Example 2 of the present invention against other gases;

[0045] Figure 5 XRD pattern of SrMoO4, a sensitive electrode material provided in Example 2 of the present invention;

[0046] Figure 6 This is a cross-sectional SEM image of the electrode material before impregnation treatment in Example 2 provided by the present invention;

[0047] Figure 7 This is a SEM image of the cross section of the electrode material after immersion treatment in Example 2 provided by the present invention.

[0048] Description of reference numerals:

[0049] 1. Sensitive material strontium molybdate particles; 2. Porous skeleton layer; 3. Electrolyte substrate; 4. Reference electrode; 5. Lead wire. DETAILED DESCRIPTION

[0050] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0051] In a first aspect, the present invention provides an electrode material comprising an electrolyte substrate and a porous skeleton layer disposed on any surface of the electrolyte substrate; the electrolyte substrate comprises a solid electrolyte, and the density of the electrolyte substrate is 5.4 to 5.5 g / cm 3 The porous skeleton layer includes an electrolyte skeleton structure and strontium molybdate particles coated on at least part of the surface of the electrolyte skeleton structure. The porosity of the porous skeleton layer is 20-30%. The solid electrolyte is La 10 Si 5.5 Al 0.5 O 27 .

[0052] The electrode material provided by the present invention ensures ion selective conduction through a dense electrolyte substrate, and the porous skeleton layer provides sufficient reaction interface. The surface of the porous skeleton layer is coated with a sensitive material strontium molybdate (SrMoO4). 10 Si 5.5 Al 0.5 O 27 ) The synergistic effect of the solid electrolyte enables the electrode material of the present invention to have a relatively wide detection range for SO2, which can reach 20 to 700 ppm, and improves the response / recovery speed and has good long-term stability.

[0053] Furthermore, the thickness of the electrolyte substrate is 1.2 to 1.3 mm; the thickness of the porous skeleton layer is 10 to 15 μm; and the electrode loading rate of the electrode material is 10 to 30%.

[0054] Among them, the electrode loading rate of the electrode material is the percentage of the mass of strontium molybdate to the mass of the entire porous layer; by optimizing the thickness of each layer and the content of sensitive materials, the best SO2 response performance is achieved while ensuring mechanical strength.

[0055] In a second aspect, the present invention provides a method for preparing the electrode material of the first aspect, comprising the following steps:

[0056] S1, performing a first ball milling process and a pre-sintering process on an electrolyte raw material system including La2O3 powder, Al2O3 powder and SiO2 powder to obtain electrolyte powder;

[0057] S2, adding a binder to the electrolyte powder and mixing, and sequentially performing a second ball milling process, a tableting process, and a densification sintering process to obtain an electrolyte substrate;

[0058] S3, adding a pore-forming agent to the electrolyte powder and performing wet grinding and mixing to obtain a pore-forming powder;

[0059] After the pore-forming powder is dried, an organic carrier is added and mixed to obtain a slurry;

[0060] The slurry is coated on any surface of the electrolyte substrate and then subjected to a first calcination treatment to form an electrolyte skeleton structure on the surface of the electrolyte substrate to obtain a double-layer electrolyte material;

[0061] S4, alternately impregnating the electrolyte skeleton structure with two impregnation solutions, a strontium source solution and a molybdenum source solution, and then performing a second calcination treatment to in-situ generate strontium molybdate particles on at least a portion of the surface of the electrolyte skeleton structure to obtain an electrode material;

[0062] The strontium source solution and the molybdenum source solution further contain a complexing agent and a surface wetting agent respectively.

[0063] Specifically, the binder includes at least one of PVB or PVA; the pore-forming agent includes at least one of graphite powder, starch or acetylene black; the organic carrier includes 94wt% terpineol and 6wt% ethyl cellulose; the strontium source in the strontium source solution is Sr(NO3)2; the molybdenum source in the molybdenum source solution is (NH4)2MoO4; the complexing agent is citric acid; and the surface wetting agent is anhydrous ethanol.

[0064] In S1, the temperature of the pre-sintering treatment is 1295-1305°C, and the time is 11.5-12.5h; in S2, the temperature of the densification sintering treatment is 1540-1560°C, and the time is 5.5-6.5h; in S3, the temperature of the first calcination treatment is 1440-1460°C, and the time is 2.8-3.2h; in S4, the temperature of the second calcination treatment is 895-905°C, and the time is 2.8-3.2h. The calcination atmosphere is air atmosphere, and it is carried out in a tubular furnace.

[0065] In S2, the amount of binder added is 1.4-1.6 wt% of the electrolyte powder;

[0066] In S3, the amount of pore former added is 28-32 wt% of the electrolyte powder;

[0067] In S3, the mass ratio of pore-forming powder to organic carrier is 3:7;

[0068] In S4, the molar concentration of the strontium source in the strontium source solution is 0.05M, the molar concentration of the molybdenum source in the molybdenum source solution is 0.05M, the ratio of the total amount of metal substances in the two impregnation solutions to the amount of citric acid is 1:1, and the molar concentration ratio of the strontium source to the molybdenum source is 1:1.

[0069] The alternating immersion treatment in S2 includes the following steps: using a 10 μL microinjector to immerse the strontium source solution into the electrolyte skeleton structure, and then immersing the electrolyte skeleton structure with an equal amount of molybdenum source solution after natural drying, and alternately immersing 1-3 times.

[0070] Before S1, the La2O3 powder was calcined at 900°C for 3 hours to remove impurities; the Al2O3 powder and SiO2 powder were dried at 120°C in a vacuum environment for 24 hours.

[0071] In a third aspect, the present invention provides a sensor comprising the electrode material of the first aspect or the electrode material prepared by the preparation method of the electrode material of the second aspect.

[0072] Specifically, the sensor further includes reference electrodes and leads disposed on both sides of the electrode material. In a specific embodiment, the method for preparing the sensor may include the following steps:

[0073] The Pt wire was bonded and fixed on both sides of the surface of the electrode material using Pt paste and calcined at 800°C for 1h to obtain a sensor.

[0074] Among them, the Pt slurry used is a purchased agent.

[0075] In a fourth aspect, the present invention provides an application of the sensor according to the third aspect in SO2 detection.

[0076] Specifically, the SO2 detection method includes: working in an impedance mode, recording the Θ response value generated by the sensor under different SO2 concentrations, and performing quantitative measurement based on the relationship between the Θ response value and the logarithm of the SO2 concentration.

[0077] See also Figure 1 The sensor provided by the present invention includes an electrode material and a reference electrode 4 and a lead 5 arranged on both sides of the surface of the electrode material; the electrode material includes an electrolyte substrate 3 and a porous skeleton layer 2 arranged on any surface of the electrolyte substrate 3; the porous skeleton layer 2 includes an electrolyte skeleton structure and sensitive material strontium molybdate particles 1 coated on at least part of the surface of the electrolyte skeleton structure.

[0078] The electrode material provided by the present invention is described in detail below through specific examples.

[0079] Example 1

[0080] The method for preparing the sensor in this embodiment includes the following steps:

[0081] S1. First, Al2O3 and SiO2 chemicals are dried in a drying oven for 24 hours, and La2O3 is calcined at 900°C for 3 hours to remove impurities; then, La2O3 powder, Al2O3 powder and SiO2 powder are accurately weighed according to the stoichiometric ratio and subjected to the first ball milling treatment in a polytetrafluoroethylene ball mill; the slurry mixed after ball milling is naturally dried and pre-sintered at 1300°C for 12 hours to obtain electrolyte powder;

[0082] S2. 1.5 wt% of a binder, polyvinyl butyral (PVB), was added to the electrolyte powder and wet-milled. The powder was then naturally dried. The powder was then pressed into a disc having a diameter of 13 mm and a thickness of approximately 1 mm using a cold isostatic press at 300 MPa. Finally, the disc was densified and sintered at 1550° C. for 6 h to obtain an electrolyte substrate.

[0083] S3, weighing 10g of electrolyte powder, adding 3g of graphite powder pore-forming agent to it by wet grinding, mixing and then naturally drying to obtain pore-forming powder;

[0084] After the pore-forming powder is dried, an organic carrier (94% wt terpineol + 6% wt ethyl cellulose) is added and mixed evenly to obtain a slurry;

[0085] The slurry is coated on any surface of the electrolyte substrate using a screen printing technique, dried at 120°C, and then subjected to a first calcination treatment at 1500°C for 3 hours to form an electrolyte skeleton structure on the surface of the electrolyte substrate to obtain a double-layer electrolyte material;

[0086] S4. Dissolve 11.1484g of Sr(NO3)2 and 9.8497g of (NH4)2MoO4 in deionized water, add 9.6543g of citric acid as a complexing agent and anhydrous ethanol as a surface wetting agent, respectively, to obtain two impregnation solutions of strontium source solution and molybdenum source solution in 50mL volumetric flasks with a molar concentration of 0.05M. 2+ With MoO4 2- The molar concentration ratio is 1:1;

[0087] A 10 μL microinjector is used to immerse the electrolyte skeleton structure in a strontium source solution. After natural drying, 10 μL of a molybdenum source solution is then immersed in the electrolyte skeleton structure, and the electrolyte skeleton structure is alternately immersed once until the amount of the strontium source solution and the molybdenum source solution each reach 10 μL. A second calcination treatment is then performed at 900° C. for 3 hours to in-situ generate strontium molybdate particles on at least a portion of the surface of the electrolyte skeleton structure to obtain an electrode material.

[0088] S5. Use Pt paste to bond and fix the thin Pt wire on both sides of the electrode material, and calcine it at 800°C for 1 hour to make a sensor.

[0089] Example 2

[0090] The difference between this embodiment and embodiment 1 is that in S4, the dipping is performed alternately twice until the dipping amounts of the strontium source solution and the molybdenum source solution both reach 20 μL.

[0091] Example 3

[0092] The difference between this embodiment and embodiment 1 is that, in S4, the dipping is performed alternately three times until the dipping amounts of the strontium source solution and the molybdenum source solution both reach 30 μL.

[0093] Test Example 1

[0094] The sensors manufactured in the above embodiments were tested.

[0095] Among them, the sensor test system consists of a tubular resistance furnace, a sealed high-temperature resistant quartz tube and a gas distribution system. The tubular resistance furnace is used to control the test temperature, and the sensor is placed in the sealed high-temperature resistant quartz tube, and the quartz tube is placed in the insulation area of ​​the tubular furnace. The sealed quartz tube consists of an air inlet and an air outlet. The air inlet is connected to the gas distribution system, and the air outlet is connected to the absorption bottle. The gas distribution system consists of a mass flow meter and a mass flow display. The SO2 standard gas (4991ppm SO2, N2 balance, Beijing Nanfei Gas Co., Ltd.) and the background gas (air) are connected to the mass flow meter. The mass flow display is used to adjust the flow rate of each gas to configure the total flow rate of 20-700ppm SO2 gas to be fixed at 200cm 3 The sensor was connected to an electrochemical workstation (CHI660E) using two platinum wires to test its sensitivity.

[0096] The above tests were performed on Examples 1, 2, and 3, respectively. The ΔΘ response value of the sensor to 700 ppm NO2 was 8.5° when tested at 0.1 Hz and 450°C in Example 1. The ΔΘ response value of the sensor to 700 ppm NO2 was 9.2° when tested at 0.1 Hz and 450°C in Example 2. The ΔΘ response value of the sensor to 700 ppm NO2 was 7.8° when tested at 0.1 Hz and 450°C in Example 3.

[0097] The test results are as follows Figures 2 to 4 shown.

[0098] like Figure 2As shown, the sensor can effectively detect SO2 concentrations from 20 to 700 ppm within the temperature range of 350°C to 550°C. At 450°C and 500°C, the Θ response is greater, and the sensor responds more clearly to SO2 concentrations below 50 ppm. However, at 500°C, the baseline exhibits a slight drift. The Θ response is smaller at 350°C, 400°C, and 550°C. The ΔΘ for 300 ppm SO2 at 350°C, 400°C, 450°C, 500°C, and 550°C are 1.7°, 4.1°, 7.1°, 7.1°, and 2.9°, respectively.

[0099] like Figure 3 As shown, at the five test temperatures, the sensor's response exhibits a linear relationship with the logarithm of the SO2 concentration. Its sensitivities at 350°C, 400°C, 450°C, and 500°C are 1.8, 3.3, 6.2, 5.7, and 3.1 decades, respectively. This indicates that the sensor has higher sensitivity at 450°C and 500°C.

[0100] like Figure 4 As shown, at a test temperature of 450°C, the response value changes of the sensor of Example 2 to 70 ppm, 300 ppm, 350 ppm, and 700 ppm SO2 alone were all less than 3% on the 7th and 14th days, indicating that the sensor has good long-term stability.

[0101] Test Example 2

[0102] The strontium molybdate material prepared in Example 2 was characterized by XRD. A Rigaku D / max-2500PC X-ray diffractometer was used, and the X-ray source was Cu Kα (λ=0.154056 nm). The characterization results are shown in FIG. Figure 5 shown.

[0103] like Figure 5 As shown, the diffraction peaks of SrMoO4 ​​correspond one to one with its standard card (JCPDS 01-085-0809), and no other obvious impurity diffraction peaks are detected, which indicates that the prepared SrMoO4 ​​sensitive electrode material is pure phase.

[0104] Test Example 3

[0105] The micromorphology of the electrolyte skeleton structure obtained in S3 in Example 2 before and after the impregnation treatment was characterized by scanning electron microscopy (SEM, JSM-IT100, JEOL). Figure 6 and Figure 7 shown.

[0106] like Figure 6 and Figure 7It can be seen that the porous skeleton layer presents a three-dimensional network porous skeleton structure with a thickness of about 13μm, which is closely connected to the dense LSAO electrolyte substrate; after impregnation of SrMoO4 ​​sensitive material, SrMoO4 ​​is evenly distributed in the entire porous skeleton structure, in the form of small particles with a diameter of 200 to 500nm and maintains relatively uniform pores. The porous skeleton layer still presents a three-dimensional network structure, which provides sufficient channels for SO2 to transfer to the three-phase interface and is more conducive to the diffusion of SO2.

[0107] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. If these modifications and variations fall within the scope of the claims of the present invention and their equivalent technologies, they should be considered to be within the scope of protection of the present invention.

Claims

1. An electrode material, characterized in that It includes an electrolyte substrate and a porous skeleton layer arranged on any surface of the electrolyte substrate; The electrolyte substrate includes a solid electrolyte, and the density of the electrolyte substrate is 5.4 to 5.5 g / cm 3 ; The porous skeleton layer includes an electrolyte skeleton structure and strontium molybdate particles coated on at least a portion of the surface of the electrolyte skeleton structure, and the porosity of the porous skeleton layer is 20-30%. The solid electrolyte is La 10 Si 5.5 Al 0.5 O 27 .

2. The electrode material according to claim 1, characterized in that The thickness of the electrolyte substrate is 1.2 to 1.3 mm; and / or, The thickness of the porous skeleton layer is 10 to 15 μm; and / or, The electrode loading rate of the electrode material is 10 to 30%.

3. A method for preparing the electrode material according to claim 1 or 2, characterized in that: The following steps are involved: S1, performing a first ball milling process and a pre-sintering process on an electrolyte raw material system including La2O3 powder, Al2O3 powder and SiO2 powder to obtain electrolyte powder; S2, adding a binder to the electrolyte powder and mixing, and sequentially performing a second ball milling process, a tableting process, and a densification sintering process to obtain an electrolyte substrate; S3, adding a pore-forming agent to the electrolyte powder and performing wet grinding and mixing to obtain a pore-forming powder; After the pore-forming powder is dried, an organic carrier is added and mixed to obtain a slurry; The slurry is coated on any surface of the electrolyte substrate and then subjected to a first calcination treatment to form an electrolyte skeleton structure on the surface of the electrolyte substrate to obtain a double-layer electrolyte material; S4, alternately impregnating the electrolyte skeleton structure with two impregnation solutions, a strontium source solution and a molybdenum source solution, and then performing a second calcination treatment to in-situ generate strontium molybdate particles on at least a portion of the surface of the electrolyte skeleton structure to obtain an electrode material; The strontium source solution and the molybdenum source solution further contain a complexing agent and a surface wetting agent respectively.

4. The method for preparing the electrode material according to claim 3, wherein: The adhesive comprises at least one of PVB or PVA; and / or, The pore-forming agent includes at least one of graphite powder, starch or acetylene black; and / or, The organic vehicle comprises 94 wt% terpineol and 6 wt% ethyl cellulose; and / or, The strontium source in the strontium source solution is Sr(NO3)2; and / or, The molybdenum source in the molybdenum source solution is (NH4)2MoO4; and / or, The complexing agent is citric acid; and / or, The surface wetting agent is anhydrous ethanol.

5. The method for preparing the electrode material according to claim 3, wherein: In S1, the pre-sintering temperature is 1295-1305°C and the time is 11.5-12.5h; and / or, In S2, the temperature of the densification sintering treatment is 1540-1560° C. and the time is 5.5-6.5 h; and / or, In S3, the temperature of the first calcination treatment is 1440-1460° C. and the time is 2.8-3.2 h; and / or, In S4, the second calcination treatment is performed at a temperature of 895 to 905° C. for a time of 2.8 to 3.2 hours in an air atmosphere.

6. The method for preparing the electrode material according to claim 3, wherein: In S2, the amount of the binder added is 1.4 to 1.6 wt % of the electrolyte powder; and / or, In S3, the amount of the pore-forming agent added is 28 to 32 wt% of the electrolyte powder; and / or, In S3, the mass ratio of the pore-forming powder to the organic carrier is 3:7; and / or, In S4, the molar concentration of the strontium source in the strontium source solution is 0.05M, the molar concentration of the molybdenum source in the molybdenum source solution is 0.05M, the ratio of the total amount of metal substances in the two impregnation solutions to the amount of citric acid is 1:1, and the molar concentration ratio of the strontium source to the molybdenum source is 1:

1.

7. The method for preparing an electrode material according to claim 3, wherein: The alternating immersion treatment in S2 includes the following steps: using a 10 μL microinjector to immerse the strontium source solution into the electrolyte skeleton structure, and then immersing the electrolyte skeleton structure with an equal amount of molybdenum source solution after natural drying, and alternately immersing 1-3 times.

8. The method for preparing an electrode material according to any one of claims 3 to 7, characterized in that: Before S1, the La2O3 powder was calcined at 900°C for 3 hours to remove impurities; the Al2O3 powder and SiO2 powder were dried at 120°C in a vacuum environment for 24 hours.

9. A sensor, characterized in that: The electrode material comprises the electrode material according to claim 1 or 2 or the electrode material prepared by the preparation method of any one of claims 3-8.

10. Use of the sensor according to claim 9 in SO2 detection.

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