阅读说明：本技术 一种SnO2掺杂的NiO纳米颗粒与乙醇传感器的制备方法及产品 (SnO (stannic oxide)2Preparation method of doped NiO nano-particle and ethanol sensor and product ) 是由 赵海波 徐祖伟 高富昌 陈志成 于 2020-12-22 设计创作，主要内容包括：本发明属于气体传感器相关技术领域,并公开了一种SnO-2掺杂的NiO纳米颗粒与乙醇传感器的制备方法及产品。该方法包括下列步骤：S1将燃料和助溶剂混合,然后在混合溶液中添加含锡的化合物和含镍的化合物,以此获得前驱体溶液；S2对所述前驱体溶液进行超声处理,使得混合均匀；S3采用对S2中混合均匀的前驱体溶液进行火焰喷雾热解,以此形成粒径为5nm～50nm的SnO-2掺杂的NiO纳米颗粒。本发明还公开了利用SnO-2掺杂的NiO纳米颗粒原位制备和非原位制备乙醇传感器的方法及产品。通过本发明,实现改善了气敏材料的气敏特性,促进该纳米材料在气乙醇气体检测领域的实用化。(The invention belongs to the related technical field of gas sensors and discloses SnO 2 A preparation method of a doped NiO nano-particle and ethanol sensor and a product. The method comprises the following steps: s1, mixing the fuel and the cosolvent, and then adding a tin-containing compound and a nickel-containing compound into the mixed solution to obtain a precursor solution; s2, carrying out ultrasonic treatment on the precursor solution to uniformly mix; s3 adopts the method that the precursor solution evenly mixed in S2 is subjected to flame spray pyrolysis to form SnO with the particle size of 5-50 nm 2 Doped NiO nanoparticles. The invention also discloses the use of SnO 2 A method for preparing an ethanol sensor in situ and ex situ by using doped NiO nano particles and a product. According to the invention, the gas-sensitive characteristic of the gas-sensitive material is improved, and the practicability of the nano material in the field of gas-ethanol gas detection is promoted.)

1. SnO (stannic oxide)₂A method for preparing doped NiO nanoparticles, comprising the steps of:

s1, mixing the fuel and the cosolvent according to the ratio of (3-10): 1, and then adding a tin-containing organic compound and a nickel-containing organic compound into the mixed solution to obtain a precursor solution;

s2, carrying out ultrasonic treatment on the precursor solution to uniformly mix;

s3 adopts the method that the precursor solution evenly mixed in S2 is subjected to flame spray pyrolysis to form SnO with the particle size of 5-50 nm₂Doped NiO nanoparticles.

2. An SnO according to claim 1₂The preparation method of the doped NiO nano-particles is characterized in that the tin-containing compound is 2-stannous ethyl hexanoate, and the nickel-containing compound is nickel acetylacetonate, nickel acetate or nickel 2-ethyl hexanoate.

3. An SnO according to claim 1₂A method for the preparation of doped NiO nanoparticles, characterized in that said SnO₂The Sn/Ni atomic ratio in the doped NiO nanoparticles was: 1 to 10 at%.

4. SnO produced by the production method according to any one of claims 1 to 3₂Doped NiO nanoparticlesAnd (4) granulating.

5. SnO obtained by the production method according to any one of claims 1 to 4₂The method for preparing the ethanol gas sensor in situ by using the doped NiO nano particles is characterized by comprising the following steps of:

the method comprises the steps of carrying out in-situ deposition on the front surface of a substrate with mutually crossed metal electrodes arranged on the front surface and heating electrodes arranged on the back surface, and depositing a layer of SnO with the thickness of 50-500 nm on the front surface of the substrate₂And doping NiO nano particles to obtain the ethanol gas sensor.

6. A method according to claim 5 using SnO₂The method for preparing the ethanol gas sensor by the doped NiO nano particles in situ is characterized in that the distance between the front surface of the substrate and flame is 40-80 cm when the in-situ deposition is carried out.

7. SnO obtained by the production method according to any one of claims 1 to 4₂A method for preparing an ethanol gas sensor ex-situ from doped NiO nanoparticles, the method comprising the steps of:

1) SnO₂Mixing the doped NiO nano particles with an adhesive, and grinding to form uniform paste; the mass ratio of the nanoparticles to the adhesive is (1-5): 10;

2) uniformly coating the paste on a substrate, wherein the front surface of the substrate is provided with metal electrodes which are mutually crossed, and the back surface of the substrate is provided with a heating electrode;

3) heating the substrate coated with the paste until the adhesive is completely removed;

4) and cooling the substrate to obtain the required ethanol gas sensor.

8. The method for ex-situ preparation of an ethanol gas sensor according to claim 7, wherein in step 1), the adhesive is terpineol, which is mixed with the SnO₂The Sn/Ni atomic ratio in the doped NiO nanoparticles was: 1-10 at.%.

9. The method for ex-situ preparation of an ethanol gas sensor according to claim 7, wherein in the step 3), the heating is performed at a low temperature of 120 ℃ to 200 ℃ for 1h to 5h, and then at a high temperature of more than 400 ℃ for 10h to 20 h.

10. The ethanol sensor obtained by the production method according to any one of claims 5 to 9, wherein the ethanol sensor has SnO with optimal gas-sensitive properties₂The loading amount is 5 at.%, and the optimal working temperature is 225-275 ℃.

Technical Field

The invention belongs to the related technical field of gas sensors, and particularly relates to SnO₂Doped NiO nanoparticle and ethanol sensorThe preparation method and the product thereof.

Background

The gas sensor is a device for detecting the type and concentration of gas, and plays a very important role in various industries at present when the society is rapidly developed, for example, the gas sensor is used for monitoring various toxic and harmful gases, detecting volatile organic compounds such as aldehydes and benzenes in automobile exhaust and home decoration, detecting alcohol after driving after drinking in the industrial field, and the like.

The resistance type semiconductor gas sensor is widely applied at present, corresponding gas concentration is obtained by measuring the real-time resistance of the sensor, and the resistance type semiconductor gas sensor is a hotspot in the research and commercial fields of gas sensors. As an important part of gas sensors, improvement of gas sensitive materials has been a subject of much attention. The requirements for high performance sensors are often not met due to the disadvantages of a single material in some respects. Therefore, the performance improvement of the gas sensitive material by methods such as heterogeneous metal oxide compounding is the most widespread technical means at present. The heterostructure formed by the composite material can regulate and control the concentration of a carrier, has the function of regulating a conductive channel, and can improve the gas-sensitive property of the gas-sensitive material by influencing the conversion capability of the sensitive material. The synthesis method of the gas-sensitive material can also have important influence on the physical and chemical properties of the gas-sensitive material, and among a plurality of synthesis methods, the flame synthesis method has the advantages of one-step synthesis, rapidness and controllable structure, can synthesize the material with high dispersity and high thermal stability, and has important significance for improving the performance of the gas sensor. In addition, flame spray pyrolysis can meet the requirement of long-term continuous preparation of nanoparticles. The gas-sensitive material with excellent gas-sensitive characteristic and the corresponding sensor are prepared by combining a flame synthesis method, and the gas-sensitive material is worthy of further discussion when used for detecting gases under various occasions and different concentrations.

Disclosure of Invention

In response to the above-identified deficiencies in the art or needs for improvement, the present invention provides a SnO₂The doped NiO nano-particle and ethanol sensor is prepared through mixing SnO₂Is compounded with NiO to form SnO₂Doped NiO nanoparticles, SnO has been found₂The optimal doping amount of the nano material improves the gas-sensitive property of the gas-sensitive material, and the nano material is utilized to prepare the ethanol sensor, so that the practicability of the nano material in the field of gas-ethanol gas detection is promoted.

In accordance with one aspect of the present invention, there is provided a SnO₂A method for preparing doped NiO nanoparticles, the method comprising the steps of:

s1 mixing the fuel and the cosolvent according to the ratio of (3-10): 1, and then adding a tin-containing compound and a nickel-containing compound into the mixed solution to obtain a precursor solution;

s2, carrying out ultrasonic treatment on the precursor solution to uniformly mix;

s3 adopts the method that the precursor solution evenly mixed in S2 is subjected to flame spray pyrolysis to form SnO with the particle size of 5-50 nm₂Doped NiO nanoparticles.

Further preferably, the tin-containing compound is stannous 2-ethyl hexanoate, and the nickel-containing compound is nickel acetylacetonate, nickel acetate or nickel 2-ethyl hexanoate.

Further preferably, the SnO₂The Sn/Ni atomic ratio in the doped NiO nanoparticles was: 1 to 10at. % of the total weight of the composition.

According to still another aspect of the present invention, there is provided SnO produced by the above-mentioned production method₂Doped NiO nanoparticles.

According to another aspect of the present invention, there is provided SnO obtained by the above-mentioned preparation method₂A method for in situ preparation of an ethanol gas sensor from doped NiO nanoparticles, the method comprising the steps of:

the method comprises the steps of carrying out in-situ deposition on the front surface of a substrate with mutually crossed metal electrodes arranged on the front surface and heating electrodes arranged on the back surface, and depositing a layer of SnO with the thickness of 50-500 nm on the front surface of the substrate₂And doping NiO nano particles to obtain the ethanol gas sensor.

Further preferably, the front surface of the substrate is spaced from the flame by a distance of 40cm to 80cm when the in-situ deposition is performed.

According to still another aspect of the present invention, there is provided SnO obtained by the above-mentioned preparation method₂A method for the ex-situ preparation of an ethanol gas sensor from doped NiO nanoparticles, the method comprising the steps of:

1) SnO₂Mixing the doped NiO nano particles with an adhesive, and grinding to form uniform paste; the mass ratio of the nanoparticles to the adhesive is (1-5): 10.

2) uniformly coating the paste on a substrate, wherein the front surface of the substrate is provided with metal electrodes which are mutually crossed, and the back surface of the substrate is provided with a heating electrode;

3) heating the substrate coated with the paste until the adhesive is completely removed;

4) and cooling the substrate to obtain the required ethanol gas sensor.

Further preferably, in step 1), the adhesive is terpineol, which is mixed with the SnO₂The Sn/Ni atomic ratio in the doped NiO nanoparticles was: 1 to 10 at.% is further preferably, in the step 3), the heating is performed at a low temperature of 120 to 200 ℃ for 1 to 5 hours, and then at a high temperature of more than 400 ℃ for 10 to 20 hours.

According to still another aspect of the present invention, there is provided an ethanol sensor obtained by the above-mentioned preparation method, wherein the ethanol sensor has SnO with optimal gas-sensing performance₂The loading amount is 5 at.%, and the optimal working temperature is 225-275 ℃.

Generally, compared with the prior art, the technical scheme of the invention has the following beneficial effects:

1. in the invention, SnO is added₂Is compounded with NiO to form SnO₂Doped NiO nanoparticles, SnO has been found₂The optimal doping amount of the nano material improves the gas-sensitive property of the gas-sensitive material, and the nano material is utilized to prepare the ethanol sensor, so that the practicability of the nano material in the field of gas-ethanol gas detection is promoted;

2. in the invention, flame spray pyrolysis is adoptedSnO synthesized by the method₂NiO nanoparticles, a process enabling the formation of stable highly dispersed heterogeneous oxides, such that SnO is obtained₂The NiO nano particles have uniform particle size, and the finally prepared ethanol sensor has high responsivity;

3. in the invention, the ethanol sensor is prepared by adopting an in-situ preparation method and an ex-situ preparation method, and the added SnO is strictly controlled in the processes of the two preparation methods₂The amount of doped NiO nano-particles ensures the finally obtained SnO in the ethanol sensor₂The load capacity is adjusted simultaneously according to the SnO₂SnO with load capacity obtaining optimal gas-sensitive performance of ethanol sensor prepared by the invention₂The loading capacity and the optimal working temperature are convenient for later use.

Drawings

FIG. 1 is a flow chart of a method of making an ethanol sensor constructed in accordance with a preferred embodiment of the present invention;

FIG. 2 is a 5 at% SnO constructed in accordance with preferred embodiment 1 of the present invention₂TEM image of NiO-sensitive material;

FIG. 3 is a graph of the response of an S-Ni-5Sn sensor constructed in accordance with the preferred embodiment 1 of the present invention to 200ppm ethanol versus temperature;

FIG. 4 is a graph showing the response and recovery curves and responsivity of S-Ni-5Sn at 250 ℃ for different concentrations of ethanol gas, wherein (a) is a graph showing the response and recovery curves for different concentrations of ethanol gas, and (b) is a graph showing the responsivity, constructed according to preferred embodiment 1 of the present invention;

FIG. 5 is a graph of selectivity and cycle performance of S-Ni-5Sn constructed according to the preferred embodiment 1 of the present invention, wherein (a) is a graph of S-Ni-5Sn selectivity to various gases and (b) is a graph of cycle performance.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

SnO (stannic oxide)₂A method for preparing doped NiO nano-particles, which comprises the following steps:

mixing liquid fuel and acetic acid according to the volume ratio of (3-10) to 1, taking the acetic acid as a cosolvent, then adding a certain amount of organic compounds of tin and nickel, dissolving the organic compounds of tin and nickel in a solvent, wherein the organic compounds of tin are 2-stannous ethyl hexanoate, the organic compounds of nickel are nickel acetate, nickel acetylacetonate and nickel 2-ethyl hexanoate, and adjusting the adding amount of the organic compounds of tin to obtain different SnO₂The contents of the materials.

And carrying out ultrasonic treatment on the mixed precursor solution for 10-30 minutes to clarify the precursor solution, and uniformly mixing all the components.

And atomizing the precursor solution to obtain liquid spray.

Igniting spray and burning dimethylbenzene to form high-temperature flame. The precursor begins to decompose and undergoes the processes of nucleation, aggregation and sintering to form SnO₂-NiO nanoparticles.

Collecting the prepared SnO on a filtration system₂-NiO nanoparticles.

In the nano gas-sensitive material, Sn is replaced by doped and high-dispersion SnO₂The fine crystallites are present in the NiO lattice and on the surface of the nanoparticles.

In the nano gas-sensitive material, the particle size of the nano particles is 5 nm-50 nm.

Using SnO₂The method for preparing the ethanol sensor by using the doped NiO nano particles as the gas sensitive material comprises an in-situ preparation method and an ex-situ preparation method, which are respectively as follows:

SnO₂The in-situ preparation method of the ethanol sensor taking the doped NiO nano particles as the gas sensitive material comprises the following steps:

1) a substrate, preferably an alumina substrate, having a front surface formed by metal electrodes crossing each other and a rear surface formed by a heating electrode and having good thermal conductivity, strength and insulation properties is placed at a position 40cm to 80cm above a flame spray pyrolysis apparatus to be used with the front surface facing downward, and in-situ deposition is performed.

2) And adjusting the distance between the substrate and the burner to adjust the particle size of the formed nanoparticles to be 5-50 nm.

3) The thickness of the nano gas-sensitive material is controlled to be 50 nm-500 nm by controlling the putting time of the substrate.

4) Taking out the substrate, and naturally cooling at room temperature to obtain SnO₂And the doped NiO nano particles are used as gas-sensitive materials.

SnO₂The ex-situ preparation method of the ethanol sensor taking the doped NiO nano particles as the gas sensitive material comprises the following steps:

1) SnO₂The doped NiO nanoparticles were homogeneously mixed with a binder, preferably terpineol, and then milled for 20-50 minutes to produce a homogeneous paste. The mass ratio of the nanoparticles to the terpineol is (1-5): 10.

2) the paste is uniformly coated on a substrate with good heat conductivity, strength and insulativity, preferably an alumina substrate, the front surface of the substrate is provided with printed intercrossed metal electrodes, the back surface of the substrate is provided with heating electrodes, the metal electrodes are used as measuring electrodes to be connected with a skin ampere meter through leads during the measurement of the sensor, the heating electrodes are connected with a stable voltage source through leads during the measurement of the sensor, and the working temperature of the sensor is set by adjusting the magnitude of the heating voltage.

3) And heating the coated substrate to 120-200 ℃ in a heating furnace for 1-5 hours, and then heating the substrate for 10-20 hours at the temperature higher than 400 ℃ to remove the terpineol and finish the aging of the sensor.

4) Naturally cooling the substrate at room temperature to obtain SnO₂And the doped NiO nano particles are used as gas-sensitive materials.

SnO with gas sensor having optimum gas-sensing properties₂The loading amount is 5 at.%, and the optimal working temperature is 225-275 ℃.

The present invention will be further illustrated with reference to specific examples.

Example 1

Mixing liquid fuel xylene and acetic acid according to a volume ratio of 4:1, taking acetic acid as a cosolvent, then adding 2-stannous ethyl hexanoate and nickel acetylacetonate, dissolving the mixture in a solvent, wherein the adding amount of the 2-stannous ethyl hexanoate is 0.405g, the mass of the nickel acetylacetonate is 12.85g, and simultaneously controlling the concentration of the nickel acetylacetonate in a precursor solution to be 0.5mol/L so as to obtain SnO with a particle size of 5-50 nm in the subsequent step₂Nanoparticles in an amount of 5 at.%.

And carrying out ultrasonic treatment on the mixed precursor solution for 10-30 minutes.

And atomizing the precursor solution to obtain liquid spray.

Igniting spray and burning dimethylbenzene to form high-temperature flame. The precursor begins to decompose and undergoes the processes of nucleation, aggregation and sintering to form SnO₂-NiO nanoparticles. Collecting the prepared SnO on a filtration system₂-NiO nanoparticles.

The preparation method of the in-situ ethanol gas sensor comprises the following steps:

and placing the aluminum oxide substrate with the front surface being the metal platinum electrodes and the back surface being the heating electrodes, wherein the front surface of the aluminum oxide substrate faces downwards and is 50cm above a used flame spray pyrolysis device for in-situ deposition. The thickness of the nano gas-sensitive material is controlled to be 50nm by controlling the putting time of the substrate. Taking out the substrate, and naturally cooling at room temperature to obtain SnO₂And the doped NiO nano particles are used as gas-sensitive materials.

The method for preparing the ethanol gas sensor ex situ comprises the following steps:

1) SnO₂The doped NiO nano particles and terpineol are uniformly mixed according to the mass ratio of 1:10, and then are ground for 20-50 minutes to prepare uniform paste.

2) The paste is uniformly coated on a substrate, preferably an alumina substrate, the front surface of the substrate is provided with printed intercrossed metal electrodes, the back surface of the substrate is provided with a heating electrode, the metal electrodes are used as measuring electrodes to be connected with a picoampere meter through leads when the sensor measures, the heating electrode is connected with a stable voltage source through leads when the sensor measures, and the working temperature of the sensor is set by adjusting the magnitude of the heating voltage.

3) The coated substrate was heated in a furnace to 120 ℃ for 1 hour, followed by 400 ℃ for 10 hours to remove the terpineol and complete the aging of the sensor.

4) Naturally cooling the substrate at room temperature to obtain SnO₂And the doped NiO nano particles are used as gas-sensitive materials.

FIG. 2 is a 5 at% SnO constructed in accordance with preferred embodiment 1 of the present invention₂TEM image of NiO gas-sensitive material, with nanoparticles having a size substantially between 8 and 20 nm.

FIG. 3 is a graph showing the response of an S-Ni-5Sn sensor constructed according to the preferred embodiment 1 of the present invention to 200ppm of ethanol as a function of temperature, with the optimal operating temperature of the sensor being 250 ℃ and the high response to ethanol gas.

Fig. 4 is a graph showing response and recovery curves and responsivity of S-Ni-5Sn constructed according to preferred embodiment 1 of the present invention at 250 c for different concentrations of ethanol gas, wherein (a) is a graph showing response and recovery curves for different concentrations of ethanol gas, and the resistance of the sensor increases significantly when the sensor S-Ni-5Sn is exposed to different concentrations of ethanol gas. And all reach a new stable value within a few seconds, and then, when the sensor is re-exposed to air, its resistance can return to the original value within a few minutes. This indicates that the sensor S-Ni-5Sn has an extremely short response time and a short recovery time characteristic to ethanol gas. (b) Is a responsivity diagram, and the sensor shows obvious response to 10ppm of ethanol gas and has lower detection lower limit. In addition, the response shows good linearity at different ethanol gas concentrations.

FIG. 5 is a graph showing selectivity and cycle performance of S-Ni-5Sn constructed according to preferred embodiment 1 of the present invention, wherein (a) is a graph showing selectivity of S-Ni-5Sn to various gases, and (b) is a graph showing cycle performance that a sensor S-5Sn has a higher response to ethanol than gases such as formaldehyde, toluene, etc., and the S-Ni-5Sn sensor shows excellent cycle performance in response to 200ppm of ethanol gas at an operating temperature of 250 ℃.

Example 2

Mixing liquid fuel xylene and acetic acid according to a volume ratio of 10:1, taking acetic acid as a cosolvent, then adding 2-stannous ethyl hexanoate and nickel acetylacetonate, dissolving the mixture in a solvent, wherein the adding amount of the 2-stannous ethyl hexanoate is 0.162g, the mass of the nickel acetylacetonate is 12.85g, and simultaneously controlling the concentration of the nickel acetylacetonate in a precursor solution to be 0.5mol/L so as to obtain 5-50 nm SnO (stannic oxide) in the subsequent step₂Nanoparticles in an amount of 2 at.%.

And carrying out ultrasonic treatment on the mixed precursor solution for 10-30 minutes.

And atomizing the precursor solution to obtain liquid spray.

Igniting spray and burning dimethylbenzene to form high-temperature flame. The precursor begins to decompose and undergoes the processes of nucleation, aggregation and sintering to form SnO₂-NiO nanoparticles. Collecting the prepared SnO on a filtration system₂-NiO nanoparticles.

The preparation method of the in-situ ethanol gas sensor comprises the following steps:

and placing the aluminum oxide substrate with the front surface being the metal platinum electrodes and the back surface being the heating electrodes, wherein the front surface of the aluminum oxide substrate faces downwards, and the aluminum oxide substrate is placed 60cm above a flame spray pyrolysis device for in-situ deposition. The thickness of the nano gas-sensitive material is controlled to be 80nm by controlling the putting time of the substrate. Taking out the substrate, and naturally cooling at room temperature to obtain SnO₂And the doped NiO nano particles are used as gas-sensitive materials.

The method for preparing the ethanol gas sensor ex situ comprises the following steps:

1) SnO₂The doped NiO nanoparticles were uniformly mixed with terpineol in a mass ratio of 2:10, and then ground for 20-50 minutes to prepare a uniform paste.

2) The paste is uniformly coated on a substrate, preferably an alumina substrate, the front surface of the substrate is provided with printed intercrossed metal electrodes, the back surface of the substrate is provided with a heating electrode, the metal electrodes are used as measuring electrodes to be connected with a picoampere meter through leads when the sensor measures, the heating electrode is connected with a stable voltage source through leads when the sensor measures, and the working temperature of the sensor is set by adjusting the magnitude of the heating voltage.

3) The coated substrate was heated in a furnace to 130 c for 2 hours, followed by 430 c for 12 hours to remove the terpineol and complete the aging of the sensor.

4) Naturally cooling the substrate at room temperature to obtain SnO₂And the doped NiO nano particles are used as gas-sensitive materials.

Example 3

Mixing liquid fuel xylene and acetic acid according to the volume ratio of 6:1, taking acetic acid as a cosolvent, then adding 2-stannous ethyl hexanoate and nickel acetate, dissolving the mixture in a solvent, wherein the adding amount of the 2-stannous ethyl hexanoate is 0.0.081g, the mass of the nickel acetate is 8.84g, and simultaneously controlling the concentration of nickel acetylacetonate in a precursor solution to be 0.5mol/L so as to obtain 5-50 nm SnO₂Nanoparticles in an amount of 1 at.%.

And carrying out ultrasonic treatment on the mixed precursor solution for 10-30 minutes.

And atomizing the precursor solution to obtain liquid spray.

Igniting spray and burning dimethylbenzene to form high-temperature flame. The precursor begins to decompose and undergoes the processes of nucleation, aggregation and sintering to form SnO₂-NiO nanoparticles. Collecting the prepared SnO on a filtration system₂-NiO nanoparticles.

The preparation method of the in-situ ethanol gas sensor comprises the following steps:

and placing the aluminum oxide substrate with the front surface being the metal platinum electrodes and the back surface being the heating electrodes, wherein the front surface of the aluminum oxide substrate faces downwards, and the aluminum oxide substrate is placed 60cm above a flame spray pyrolysis device for in-situ deposition. The thickness of the nano gas-sensitive material is controlled to be 100nm by controlling the putting time of the substrate. Taking out the substrate, and naturally cooling at room temperature to obtain SnO₂And the doped NiO nano particles are used as gas-sensitive materials.

The method for preparing the ethanol gas sensor ex situ comprises the following steps:

1) SnO₂Doped NiOUniformly mixing and uniformly mixing the nano particles and the terpineol according to the mass ratio of 3:10, and then grinding for 20-50 minutes to prepare uniform paste.

2) The paste is uniformly coated on a substrate, preferably an alumina substrate, the front surface of the substrate is provided with printed intercrossed metal electrodes, the back surface of the substrate is provided with a heating electrode, the metal electrodes are used as measuring electrodes to be connected with a picoampere meter through leads when the sensor measures, the heating electrode is connected with a stable voltage source through leads when the sensor measures, and the working temperature of the sensor is set by adjusting the magnitude of the heating voltage.

3) The coated substrate was heated in a furnace to 150 c for 3 hours, followed by 450 c for 11 hours to remove the terpineol and complete the aging of the sensor.

4) Naturally cooling the substrate at room temperature to obtain SnO₂And the doped NiO nano particles are used as gas-sensitive materials.

Example 4

Mixing liquid fuel xylene and acetic acid in a volume ratio of 3:1, taking acetic acid as a cosolvent, then adding 2-stannous ethyl hexanoate and nickel acetate, dissolving the mixture in a solvent, wherein the adding amount of the 2-stannous ethyl hexanoate is 0.81g, the mass of the nickel acetate is 8.84g, and simultaneously controlling the concentration of nickel acetylacetonate in a precursor solution to be 0.5mol/L so as to obtain 5-50 nm SnO₂Nanoparticles in an amount of 10 at.%.

And carrying out ultrasonic treatment on the mixed precursor solution for 10-30 minutes.

And atomizing the precursor solution to obtain liquid spray.

Igniting spray and burning dimethylbenzene to form high-temperature flame. The precursor begins to decompose and undergoes the processes of nucleation, aggregation and sintering to form SnO₂-NiO nanoparticles. Collecting the prepared SnO on a filtration system₂-NiO nanoparticles.

The preparation method of the in-situ ethanol gas sensor comprises the following steps:

the front surface of the aluminum oxide substrate is provided with mutually crossed metal platinum electrodes and the back surface is provided with a heating electrode, and the front surface faces downwardsThe in-situ deposition was carried out by placing the reactor 70cm above the flame spray pyrolysis apparatus used. The putting time of the substrate is controlled to control the thickness of the nano gas sensitive material to be 90 nm. Taking out the substrate, and naturally cooling at room temperature to obtain SnO₂And the doped NiO nano particles are used as gas-sensitive materials.

The method for preparing the ethanol gas sensor ex situ comprises the following steps:

1) SnO₂The doped NiO nanoparticles and terpineol are uniformly mixed and mixed according to the mass ratio of 4:10, and then ground for 20-50 minutes to prepare a uniform paste.

2) The paste is uniformly coated on a substrate, preferably an alumina substrate, the front surface of the substrate is provided with printed intercrossed metal electrodes, the back surface of the substrate is provided with a heating electrode, the metal electrodes are used as measuring electrodes to be connected with a picoampere meter through leads when the sensor measures, the heating electrode is connected with a stable voltage source through leads when the sensor measures, and the working temperature of the sensor is set by adjusting the magnitude of the heating voltage.

3) The coated substrate was heated in a furnace to 140 c for 1 hour, followed by 450 c for 13 hours to remove the terpineol and complete the aging of the sensor.

4) Naturally cooling the substrate at room temperature to obtain SnO₂And the doped NiO nano particles are used as gas-sensitive materials.

Example 5

Mixing liquid fuel xylene and acetic acid according to a volume ratio of 4:1, taking acetic acid as a cosolvent, then adding 2-stannous ethyl hexanoate and nickel 2-ethyl hexanoate, dissolving the mixture in a solvent, wherein the adding amount of the 2-stannous ethyl hexanoate is 0.162g, the mass of the nickel 2-ethyl hexanoate is 17.26g, and simultaneously controlling the concentration of nickel acetylacetonate in a precursor solution to be 0.5mol/L so as to obtain 5-50 nm SnO (stannic oxide) in the subsequent step₂Nanoparticles in an amount of 2 at.%.

And carrying out ultrasonic treatment on the mixed precursor solution for 10-30 minutes.

And atomizing the precursor solution to obtain liquid spray.

Igniting spray and burning dimethylbenzene to form high-temperature flame. The precursor begins to decompose and undergoes the processes of nucleation, aggregation and sintering to form SnO₂-NiO nanoparticles. Collecting the prepared SnO on a filtration system₂-NiO nanoparticles.

The preparation method of the in-situ ethanol gas sensor comprises the following steps:

and placing the aluminum oxide substrate with the front surface being the metal platinum electrodes and the back surface being the heating electrodes, wherein the front surface of the aluminum oxide substrate faces downwards, and the aluminum oxide substrate is arranged 80cm above the used flame spray pyrolysis device for in-situ deposition. The thickness of the nano gas-sensitive material is controlled to be 110nm by controlling the putting time of the substrate. Taking out the substrate, and naturally cooling at room temperature to obtain SnO₂And the doped NiO nano particles are used as gas-sensitive materials.

The method for preparing the ethanol gas sensor ex situ comprises the following steps:

1) SnO₂The doped NiO nano particles and terpineol are uniformly mixed according to the mass ratio of 5:10, and then are ground for 20-50 minutes to prepare uniform paste.

2) The paste is uniformly coated on a substrate, preferably an alumina substrate, the front surface of the substrate is provided with printed intercrossed metal electrodes, the back surface of the substrate is provided with a heating electrode, the metal electrodes are used as measuring electrodes to be connected with a picoampere meter through leads when the sensor measures, the heating electrode is connected with a stable voltage source through leads when the sensor measures, and the working temperature of the sensor is set by adjusting the magnitude of the heating voltage.

3) The coated substrate was heated in a furnace to 160 ℃ for 2 hours, followed by 400 ℃ for 11 hours to remove the terpineol and complete the aging of the sensor.

4) Naturally cooling the substrate at room temperature to obtain SnO₂And the doped NiO nano particles are used as gas-sensitive materials.

Example 6

Mixing liquid fuel xylene and acetic acid at a volume ratio of 5:1, using acetic acid as a cosolvent, and then adding 2-stannous ethyl hexanoate and 2-ethyl acetateDissolving nickel caproate in solvent, adding 2-ethyl stannous caproate in 0.405g and nickel 2-ethyl caproate in 17.26g while controlling the concentration of nickel acetylacetonate in the precursor solution to 0.5mol/L for subsequent 5-50 nm SnO₂Nanoparticles in an amount of 5 at.%.

And carrying out ultrasonic treatment on the mixed precursor solution for 10-30 minutes.

And atomizing the precursor solution to obtain liquid spray.

Igniting spray and burning dimethylbenzene to form high-temperature flame. The precursor begins to decompose and undergoes the processes of nucleation, aggregation and sintering to form SnO₂-NiO nanoparticles. Collecting the prepared SnO on a filtration system₂-NiO nanoparticles.

The preparation method of the in-situ ethanol gas sensor comprises the following steps:

and placing the aluminum oxide substrate with the front surface being the metal platinum electrodes and the back surface being the heating electrodes, wherein the front surface of the aluminum oxide substrate faces downwards, and the aluminum oxide substrate is placed 40cm above a flame spray pyrolysis device for in-situ deposition. The thickness of the nano gas-sensitive material is controlled to be 500nm by controlling the putting time of the substrate. Taking out the substrate, and naturally cooling at room temperature to obtain SnO₂And the doped NiO nano particles are used as gas-sensitive materials.

The method for preparing the ethanol gas sensor ex situ comprises the following steps:

1) SnO₂The doped NiO nano particles and terpineol are uniformly mixed according to the mass ratio of 5:10, and then are ground for 20-50 minutes to prepare uniform paste.

2) The paste is uniformly coated on a substrate, preferably an alumina substrate, the front surface of the substrate is provided with printed intercrossed metal electrodes, the back surface of the substrate is provided with a heating electrode, the metal electrodes are used as measuring electrodes to be connected with a picoampere meter through leads when the sensor measures, the heating electrode is connected with a stable voltage source through leads when the sensor measures, and the working temperature of the sensor is set by adjusting the magnitude of the heating voltage.

3) The coated substrate was heated in a furnace to 200 c for 5 hours, followed by 400 c for 20 hours to remove the terpineol and complete the aging of the sensor.

4) Naturally cooling the substrate at room temperature to obtain SnO₂And the doped NiO nano particles are used as gas-sensitive materials.

It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.