A nitric oxide sensor based on fishbone perovskite Cs2TeI6 and its preparation method and application

Abstract

The present invention discloses a nitric oxide sensor based on fishbone perovskite Cs2TeI6 and its preparation method and application. Specifically, the nitric oxide sensor of the present invention comprises a membrane material and an interdigital electrode, wherein the membrane material is a fishbone perovskite Cs2TeI6, which is brush-coated on the interdigital electrode with a thickness of 5 to 50 μm, and has the following advantages: convenient preparation and simple operation; extremely low concentration of nitric oxide (60 ppb) can be detected; and the device has stable performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic semiconductor materials, and in particular relates to a nitric oxide sensor based on fishbone perovskite Cs2TeI6, a preparation method thereof, and use thereof in environmental nitric oxide detection. Background Art

[0002] In daily life, the exhaust of cars and portable generators, as well as the incomplete combustion of some fuels (including wood, coal, oil, natural gas and waste) will produce nitric oxide. Nitric oxide is a colorless and odorless gas. When the concentration in the air reaches a certain limit, it can even cause human death. Therefore, the detection of nitric oxide is particularly important. At present, nitric oxide sensors are a hot topic in the field of sensor devices. Common nitric oxide sensor devices are basically based on metal oxide materials. Although they have good stability, they have poor responsiveness, high detection limits, and complex preparation processes, which are not suitable for large-scale applications. In order to meet the current market requirements for sensors that are cheap, practical, and easy to prepare, it is urgent to develop a new type of nitric oxide sensor. Summary of the invention

[0003] In view of the above situation, the present invention uses fishbone perovskite Cs2TeI6 to prepare a nitric oxide sensor, and detects different concentrations of nitric oxide by observing the current change of the sensor under different concentrations of nitric oxide. The present invention tests the current change of the nitric oxide sensor under different concentrations of nitric oxide and the recovery of the device. The device is first placed in a pure nitrogen environment to measure its current, and then the content of nitric oxide in the environment is continuously increased and its current is measured.

[0004] Specifically, the present invention adopts the following technical solutions:

[0005] Application of fishbone-shaped perovskite Cs2TeI6 in the preparation of nitric oxide sensor; or application of fishbone-shaped perovskite Cs2TeI6 in the preparation of nitric oxide sensor membrane material.

[0006] A nitric oxide sensor based on fishbone-shaped perovskite Cs2TeI6 comprises a membrane material and interdigital electrodes; the membrane material is a fishbone-shaped perovskite Cs2TeI6 layer.

[0007] The method for preparing the nitric oxide sensor based on the fishbone perovskite Cs2TeI6 comprises the following steps: applying a fishbone perovskite Cs2TeI6 solution on the interdigital electrodes, heating and drying, and preparing the nitric oxide sensor based on the fishbone perovskite Cs2TeI6.

[0008] The nitric oxide sensor of the present invention comprises a membrane material and an interdigital electrode; the thickness of the membrane material is 5 to 50 μm, preferably 8 to 20 μm; the interdigital electrode is based on aluminum oxide (Al2O3), and a silver-palladium alloy (Ag-Pd) is arranged on the substrate; the interdigital width of the interdigital electrode is 200 to 300 μm, and the interdigital spacing is 100 to 200 μm; the thickness of the substrate is 1 to 2 mm; the thickness of the silver-palladium alloy is 100 to 200 nm.

[0009] In the present invention, the perovskite Cs2TeI6, solvent and isobutanol are stirred to obtain the fishbone perovskite Cs2TeI6, preferably at a stirring speed of 500 rpm; the amount ratio of the perovskite Cs2TeI6, solvent and isobutanol is 150-200 mg: 1 mL: 10 mL, preferably 160 mg: 1 mL: 10 mL; the solvent is a mixed solvent of N,N-dimethylformamide and dimethyl sulfoxide, preferably N,N-dimethylformamide and dimethyl sulfoxide are mixed in a volume ratio of 1:1. In the present invention, the perovskite Cs2TeI6 and the solvent are heated and then stirred with isobutanol, the heating temperature is 60°C, the time is 1-3 h, and the preferred temperature is 60°C and the time is 2 h.

[0010] In the present invention, the temperature of the heating and drying device is 70-100° C., and the time is 4-6 min. The preferred temperature is 90° C., and the time is 5 min.

[0011] In the present invention, cesium iodide and tellurium iodide are dissolved in a hydrogen iodide solution and heated to react to prepare perovskite Cs2TeI6 with a non-hollow structure.

[0012] The application of the above-mentioned nitric oxide sensor based on fishbone perovskite Cs2TeI6 in detecting nitric oxide.

[0013] Specifically, the preparation method of the nitric oxide sensor based on the fishbone perovskite Cs2TeI6 is exemplified as follows:

[0014] (1) Ultrasonic clean the interdigital electrodes with deionized water and ethanol for 10 min respectively, and blow dry;

[0015] (2) Dissolve the perovskite Cs2TeI6 in 1 mL of solvent and heat at 60°C for 2 h to obtain solution 1;

[0016] (3) Take 20 μL of solution 1 and add it to 10 mL of isobutanol, stir for 30 min, and then let it stand for 12 h to obtain solution 2.

[0017] (4) The second lower layer precipitation solution is brushed onto the surface of the interdigital electrode and dried to obtain a nitric oxide sensor based on the fishbone perovskite Cs2TeI6.

[0018] Compared with the prior art, the present invention using the above technical solution has the following advantages:

[0019] (1) The device is easy to prepare and operate;

[0020] (2) Low detection limit. The minimum detection concentration of nitric oxide is lower than that of common metal oxides.

[0021] (3) The device performance is stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A is the SEM spectrum of perovskite Cs2TeI6, and B is the schematic diagram of the structure of perovskite Cs2TeI6;

[0023] Figure 2 is the XRD spectrum of perovskite Cs2TeI6;

[0024] Figure 3 A is the SEM spectrum of the fishbone perovskite Cs2TeI6, B is the TEM spectrum of the fishbone perovskite Cs2TeI6, and C is the XRD spectrum of the fishbone perovskite Cs2TeI6;

[0025] Figure 4 A is a schematic diagram of the structure of the nitric oxide sensor based on the fishbone perovskite Cs2TeI6, and B is a schematic diagram of the sensor preparation;

[0026] Figure 5 SEM images of perovskite Cs2TeI6 obtained with different solvents;

[0027] Figure 6 The response of Cs2TeI6 nitric oxide sensor varies with the concentration of nitric oxide;

[0028] Figure 7 This is the response recovery time diagram of the Cs2TeI6 nitric oxide sensor;

[0029] Figure 8 Repeatability of Cs2TeI6 nitric oxide sensor for NO (a) 60 ppb, (b) 200 ppb, (c) 500 ppb, (d) 1 ppm;

[0030] Fig. 9 Response of Cs2TeI6 nitric oxide sensor to different gases. DETAILED DESCRIPTION

[0031] The technical solution of the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. Unless otherwise specified, the reagents, materials, instruments, etc. used in the following embodiments can be obtained through commercial means; unless otherwise specified, the parameters and environment of the embodiments are conventional technologies; the substrate and interdigital electrodes are existing products; unless otherwise specified, all tests are performed at room temperature.

[0032] The performance of the sensor was monitored by direct current-time (I-T), which was measured using a semiconductor Keithley 4200A-SCS with a constant voltage of 10 V. During the test, the prepared sensor device was placed in a 0.1 L chamber at 25 °C, and pure N2 was used as a carrier gas to achieve the desired NO concentration before the test. The sensor device was purged with pure nitrogen until the state of the sensor did not change to eliminate the interference of other factors, and then the target gas (NO) was purged into the chamber. In order to ensure the accuracy of the data, the time interval for each test was set to 3 min. In order to reduce the influence of the gas flow rate, the flow rate was fixed at 250 mL / min.

[0033] Example 1: Synthesis of perovskite Cs2TeI6 and preparation of sensor

[0034] (1) Synthesis of perovskite Cs2TeI6

[0035] Weigh cesium iodide (519.6 mg, 2 mmol) and dissolve it in 20 ml methanol. Heat it in a water bath at 60°C to obtain solution A. Weigh tellurium iodide (635.2 mg, 1 mmol) and add it to 8 ml n-butyl acetate and 4 ml hydrogen iodide solution (ACS, 55-58%) to obtain solution B. Pour solution B into solution A, heat at 60°C and stir to react for 30 min. Turn off the heating stage, cool naturally to room temperature, and centrifuge and filter the product. After washing with n-butyl acetate, dry it in a vacuum oven at 80°C for 10 h to obtain the product perovskite Cs2TeI6. Its SEM microstructure is shown in the following figure. Figure 1 Its X-ray diffraction pattern is shown in Figure 2 As shown. Figure 1 A shows that Cs2TeI6 is a relatively uniform octahedral small particle; the structural diagram is as follows Figure 1 B. By Figure 2 It can be seen that the Cs2TeI6 synthesized above completely corresponds to the PDF card of the standard Cs2TeI6, which confirms that the synthesis is successful.

[0036] (2) Synthesis of fishbone-like perovskite Cs2TeI6 and preparation of sensors

[0037] (a) The interdigital electrode was ultrasonically cleaned with deionized water and ethanol for 10 min respectively and then dried. The interdigital length was 7 mm, the width was 0.2 mm, and the interdigital spacing was 0.2 mm.

[0038] (b) 160 mg of the above perovskite Cs2TeI6 was dissolved in 1 mL of a mixed solvent of N,N-dimethylformamide and dimethyl sulfoxide in a volume ratio of 1:1, and heated at 60°C for 2 h to obtain solution 1;

[0039] (c) Take 20 μL of the solution and add it to 10 mL of isobutanol and stir at 500 rpm for 30 min to obtain fishbone-shaped perovskite Cs2TeI6. Its SEM microstructure is shown in Figure 2. Figure 3 As shown in A, its TEM microstructure is as follows Figure 3 B, its X-ray diffraction pattern is as follows Figure 3 C; Figure 3 It can be seen that Cs2TeI6 is transformed into a fishbone morphology. The synthesized fishbone-shaped Cs2TeI6 completely corresponds to the standard Cs2TeI6 PDF card, which can confirm that the material itself does not undergo phase change while the morphology changes;

[0040] (d) the fishbone-shaped perovskite Cs2TeI6 solution was allowed to stand for 12 h to obtain solution 2;

[0041] (e) The second lower layer of the precipitated solution is brushed onto the surface of the interdigital electrode and heated by an infrared drying lamp to obtain a nitric oxide sensor based on the fishbone perovskite Cs2TeI6; the schematic diagram of the sensor structure is shown in Figure 4 As shown in A, the thickness of the Cs2TeI6 film is 14 μm;

[0042] The schematic diagram of the preparation of the above sensor is shown in Figure 4 As shown in B.

[0043] As a comparison, the above isobutanol was replaced with other solvents, and the rest remained unchanged. The morphology of Cs2TeI6 was shown in Figure 5 .

[0044] Example 2: Response measurement experiment of nitric oxide sensor under different nitric oxide concentration environments

[0045] The nitric oxide sensor based on the fishbone perovskite Cs2TeI6 prepared in Example 1 was placed in a testing machine. Under the condition of applying a constant voltage of 20 V, the response change of the device in the range of 60 ppb-3 ppm was tested. The results are as follows: Figure 6 As shown, Figure 7 Give it a response time.

[0046] from Figure 7It can be seen that for different concentrations of nitric oxide atmosphere (diluted with nitrogen), the sensor based on the fishbone perovskite Cs2TeI6 responds significantly; the minimum detection limit can reach 60 ppb. In parallel experiments, the sensor made of the existing perovskite Cs2PtI6 (DOI: 10.1021 / acssensors.1c01791) has a minimum detection limit of 200 ppb for NO, and basically no response at 100 ppb.

[0047] Figure 8 Repeatability of Cs2TeI6 nitric oxide sensor for NO (a) 60 ppb, (b) 200 ppb, (c) 500 ppb, (d) 1 ppm; Fig. 9 The above is a comparison of the responses of the above sensors to different gases at 10ppm. In summary, the present invention realizes the detection of nitric oxide at different concentrations by making a fishbone-shaped perovskite Cs2TeI6 into a simple resistive thin film sensor, and the minimum detection limit can reach 60 ppb, realizing the application of perovskite in the field of nitric oxide sensing. The nitric oxide sensor based on the fishbone-shaped perovskite Cs2TeI6 of the present invention has a high application value for the detection of nitric oxide in the future environment.

Claims

1. Application of fishbone-shaped perovskite Cs2TeI6 in the preparation of nitric oxide sensor, characterized in that: Weigh cesium iodide and dissolve it in methanol, heat it in a water bath to obtain solution A, then weigh tellurium iodide and add it to n-butyl acetate and hydrogen iodide solution to obtain solution B, pour solution B into solution A, heat and stir to react; turn off the heating table, cool naturally to room temperature, centrifuge and filter the product, wash it with n-butyl acetate, and dry it in a vacuum oven to obtain the product perovskite Cs2TeI6; mix and stir the perovskite Cs2TeI6, solvent and isobutanol to obtain fishbone perovskite Cs2TeI6; the solvent is a mixed solvent of N,N-dimethylformamide and dimethyl sulfoxide.

2. Application of fishbone-shaped perovskite Cs2TeI6 in the preparation of nitric oxide sensor membrane materials, characterized in that: Weigh cesium iodide and dissolve it in methanol, heat it in a water bath to obtain solution A, then weigh tellurium iodide and add it to n-butyl acetate and hydrogen iodide solution to obtain solution B, pour solution B into solution A, heat and stir to react; turn off the heating table, cool naturally to room temperature, centrifuge and filter the product, wash it with n-butyl acetate, and dry it in a vacuum oven to obtain the product perovskite Cs2TeI6; mix and stir the perovskite Cs2TeI6, solvent and isobutanol to obtain fishbone perovskite Cs2TeI6; the solvent is a mixed solvent of N,N-dimethylformamide and dimethyl sulfoxide.

3. The use according to claim 1 or 2, characterized in that: The nitric oxide sensor comprises a membrane material and interdigital electrodes; the thickness of the membrane material is 5 to 50 μm.

4. A nitric oxide sensor based on fishbone perovskite Cs2TeI6, comprising a membrane material and an interdigitated electrode; the membrane material is fishbone perovskite Cs2TeI6, characterized in that: Weigh cesium iodide and dissolve it in methanol, heat it in a water bath to obtain solution A, then weigh tellurium iodide and add it to n-butyl acetate and hydrogen iodide solution to obtain solution B, pour solution B into solution A, heat and stir to react; turn off the heating table, cool naturally to room temperature, centrifuge and filter the product, wash it with n-butyl acetate, and dry it in a vacuum oven to obtain the product perovskite Cs2TeI6; mix and stir the perovskite Cs2TeI6, solvent and isobutanol to obtain fishbone perovskite Cs2TeI6; the solvent is a mixed solvent of N,N-dimethylformamide and dimethyl sulfoxide.

5. The nitric oxide sensor based on the fishbone perovskite Cs2TeI6 according to claim 4, characterized in that: The interdigital electrode is based on aluminum oxide, on which a silver-palladium alloy is arranged; the thickness of the membrane material is 5 to 50 μm.

6. The method for preparing a nitric oxide sensor based on fishbone perovskite Cs2TeI6 according to claim 4, characterized in that: The method comprises the following steps: brushing a fishbone-shaped perovskite Cs2TeI6 solution on an interdigital electrode, heating the solution, and preparing a nitric oxide sensor based on the fishbone-shaped perovskite Cs2TeI6.

7. Use of the nitric oxide sensor based on the fishbone perovskite Cs2TeI6 as claimed in claim 4 in detecting nitric oxide.

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