A method for preparing a gas sensor

Abstract

The application discloses a preparation method of a gas sensor. The method comprises the following steps: firstly, depositing interdigital electrodes on a ceramic substrate; then, coating isopropyl alcohol amine solution of cuprous iodide on the surface of the ceramic substrate and the interdigital electrodes; subsequently, placing the solution in argon at a certain temperature for a period of time to obtain cuprous iodide nanoflower composite thin film material dispersed in cuprous iodide-isopropyl alcohol amine hybrid, and finally obtaining the gas sensor. The cuprous iodide nanoflower dispersed in the cuprous iodide-isopropyl alcohol amine hybrid serves as a gas sensitive layer, has very high selectivity to ammonia, and has a response degree of nearly 10 6 ; the cuprous iodide dispersed in the cuprous iodide-isopropyl alcohol amine hybrid prepared by the method has a nanoflower morphology, the cuprous iodide is self-assembled in a nanoflower pattern, has high dispersibility of nanoparticles, good connection between the nanoparticles, and good electrical contact between the nanoparticles.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of device preparation, and particularly relates to a preparation method of a cuprous iodide (CuI) based thin film gas sensor. BACKGROUND

[0002] Cuprous iodide exhibits the properties of an ion semiconductor material, and its resistance will change after adsorbing gas molecules on the surface, so it is often used as a gas sensitive material. Because the nucleophilic force between copper ions and nitrogen elements is large, copper-containing compounds have good selective adsorption properties for nitrogen-containing gas molecules, and copper compounds can be used as selective gas sensitive sensor materials for nitrogen-containing gas molecules. Cuprous iodide has been studied in the field of ammonia gas detection, but the adsorption force of cuprous iodide for ammonia gas is not strong enough, and the adsorption amount of ammonia gas molecules is small, and the adsorption response (the relative change of resistance before and after adsorption (R 氨气 -R 空气 ) / R 空气 ) is relatively low. SUMMARY

[0003] The present application proposes a preparation method of a gas sensor to overcome the deficiencies of the prior art.

[0004] First, a interdigital electrode is deposited; then, an isopropyl alcohol amine solution of cuprous iodide is applied on the surface of the ceramic substrate and the interdigital electrode; subsequently, the product is placed in an argon atmosphere at 90-150 ℃ for 240-420 min to obtain a cuprous iodide nanoflower composite thin film material dispersed in a cuprous iodide-isopropyl alcohol amine hybrid, and a gas sensor is obtained.

[0005] As a preferred embodiment, the deposition of the interdigital electrode specifically comprises: depositing a 100-500 nm thick gold interdigital electrode on the surface of the ceramic substrate by a thermal evaporation method.

[0006] As a preferred embodiment, the product is placed in an argon atmosphere at 90-150 ℃ for 240-420 min; specifically, the product is placed in an electric furnace, and the heating rate is 5-10 ℃ / min.

[0007] As a preferred embodiment, the temperature is 90 ℃.

[0008] As a preferred embodiment, the placement time is 360 min.

[0009] The cuprous iodide nanoflower dispersed in the cuprous iodide-isopropyl alcohol amine hybrid of the present application has very high selectivity to ammonia gas as a gas sensitive layer, and the response degree is as high as nearly 10 6 .

[0010] The cuprous iodide prepared by the method is dispersed in the cuprous iodide-isopropyl alcohol amine hybrid, and the cuprous iodide has a nanoflower appearance, and the cuprous iodide has a nanoflower pattern self-assembly, has high dispersibility of nanoparticles, good connection between particles, and good electrical contact between particles.

[0011] The thin film prepared by the method contains the cuprous iodide-isopropyl alcohol amine hybrid, and the adsorption performance on ammonia molecules is increased. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 It is a SEM image of the nanoflower of the cuprous iodide embedded in the cuprous iodide-isopropyl alcohol amine hybrid;

[0013] Figure 2 It is an adsorption response schematic diagram of the cuprous iodide (Cul) based thin film gas sensor of example 1. DETAILED DESCRIPTION

[0014] Example 1:

[0015] Step (1). A ceramic substrate is deposited with a 100 nm thick gold interdigital electrode on the surface thereof by a thermal evaporation method;

[0016] Step (2). Cuprous iodide powder is placed in a beaker, and a certain volume of ethylene glycol amine is added into the beaker to form an isopropyl alcohol amine solution of cuprous iodide;

[0017] Step (3). The solution of step (2) is transferred to the surface of the interdigital electrode of step (1) by a pipette;

[0018] Step (4). The product of step (3) is placed in an electric furnace under an argon atmosphere protection, and heated to 90 DEG C at a heating rate of 5 DEG C / min; after the temperature is increased to 90 DEG C, the temperature is kept constant, and the holding time is 240 min;

[0019] Step (5). The electric furnace is stopped heating, and a thin film formed by the nanoflower of cuprous iodide dispersed in the cuprous iodide-isopropyl alcohol amine hybrid is obtained, and the SEM image thereof is shown in Figure 1 ; and the device preparation is completed. As shown in Figure 2 , it is an adsorption response schematic diagram of the prepared cuprous iodide (Cul) based thin film gas sensor.

[0020] Example 2:

[0021] Step (1). A ceramic substrate is deposited with a 300 nm thick gold interdigital electrode on the surface thereof by a thermal evaporation method;

[0022] Step (2). Cuprous iodide powder is placed in a beaker, and a certain volume of ethylene glycol amine is added into the beaker to form an isopropyl alcohol amine solution of cuprous iodide;

[0023] Step (3). The solution of step (2) is pipetted onto the surface of the interdigital electrode of step (1);

[0024] Step (4). The product of step (3) is placed in an electric furnace under argon atmosphere and heated to 120 °C at a rate of 7 °C / min. After the temperature reaches 120 °C, the temperature is maintained for 270 min;

[0025] Step (5). The electric furnace is stopped and a film of cuprous iodide nanoflowers dispersed in the cuprous iodide-isopropylamine hybrid is obtained. The device is completed.

[0026] Example Three:

[0027] Step (1). A ceramic substrate is coated with a 100-500 nm thick gold interdigital electrode by thermal evaporation;

[0028] Step (2). Cuprous iodide powder is placed in a beaker and a certain volume of isopropylamine is added to the beaker to form a cuprous iodide-isopropylamine solution;

[0029] Step (3). The solution of step (2) is pipetted onto the surface of the interdigital electrode of step (1);

[0030] Step (4). The product of step (3) is placed in an electric furnace under argon atmosphere and heated to 150 °C at a rate of 10 °C / min. After the temperature reaches 150 °C, the temperature is maintained for 420 min;

[0031] Step (5). The electric furnace is stopped and a film of cuprous iodide nanoflowers dispersed in the cuprous iodide-isopropylamine hybrid is obtained. The device is completed.

Claims

1. A method for preparing an ammonia gas sensor, characterized by: The ceramic substrate is deposited with 100-500 nm thick gold interdigital electrodes on its surface by a thermal evaporation method; then the ceramic substrate and the interdigital electrode surface are coated with a cuprous iodide isopropanol amine solution; subsequently, the product is placed in an electric furnace and placed in argon at 90-150 DEG C for 240-420 min, with a heating rate of 5-10 DEG C / min, to obtain a cuprous iodide nanoflower composite thin film material dispersed in a cuprous iodide-isopropanol amine hybrid, and a gas sensitive sensor, wherein the gas sensitive active material of the gas sensitive sensor is the cuprous iodide nanoflower in addition to the cuprous iodide-isopropanol amine hybrid.

2. The method for preparing an ammonia gas sensor according to claim 1, wherein: The temperature is 90 DEG C.

3. The method for preparing an ammonia gas sensor according to claim 1, characterized in that: The placement time is 360 min.

4. The method for preparing an ammonia gas sensor according to claim 1, characterized in that: The cuprous iodide morphology is nanoflower.

5. The method for preparing an ammonia gas sensor according to claim 1, characterized in that: The cuprous iodide nanoflower is embedded in the cuprous iodide-isopropanol amine hybrid.

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