阅读说明：本技术 一种Cu掺杂Sn3O4的气敏材料及其甲醛气体传感器和制备方法、应用 (A kind of Cu doping Sn3O4Gas sensitive and its formaldehyde gas sensor and preparation method, application ) 是由 李阳 王蕾 李念强 张春伟 岳文静 于 2019-07-17 设计创作，主要内容包括：本发明涉及气体传感器技术领域,尤其涉及一种Cu掺杂Sn_3O_4的气敏材料及其甲醛气体传感器和制备方法、应用。所述气敏材料包括：Sn_3O_4纳米片和铜离子,所述Sn_3O_4纳米片堆叠后形成三维的花状结构,所述铜离子存在于Sn_3O_4晶格之中取代Sn_3O_4晶格中的部分锡离子以及Sn_3O_4纳米片上和Sn_3O_4晶格间隙中。本发明以Cu掺杂的具有花状结构的Sn_3O_4为甲醛气体传感器敏感材料,制备的气体传感器在较低的工作温度下,具有大响应值,良好的甲醛气体选择性和快响应和恢复速度,并且能够有效降低实验操作复杂度,节约实验成本。(The present invention relates to gas sensor technical fields more particularly to a kind of Cu to adulterate Sn 3 O 4 Gas sensitive and its formaldehyde gas sensor and preparation method, application.The gas sensitive includes: Sn 3 O 4 Nanometer sheet and copper ion, the Sn 3 O 4 Nanometer sheet heap poststack forms three-dimensional flower-like structure, and the copper ion is present in Sn 3 O 4 Replace Sn among lattice 3 O 4 Part tin ion and Sn in lattice 3 O 4 In nanometer sheet and Sn 3 O 4 In interstitial void.The Sn with flower-like structure that the present invention is adulterated with Cu 3 O 4 For formaldehyde gas sensor sensitive material, the gas sensor of preparation at lower operating temperatures, has big response, good formaldehyde gas selectivity and fast-response and resume speed, and can be effectively reduced experimental implementation complexity, saves experimental cost.)

1. a kind of Cu adulterates Sn₃O₄Gas sensitive characterized by comprising Sn₃O₄Nanometer sheet and copper ion, the Sn₃O₄It receives Rice piece heap poststack forms three-dimensional flower-like structure, and the copper ion is present in Sn₃O₄Replace Sn among lattice₃O₄Portion in lattice Divide tin ion and Sn₃O₄In nanometer sheet and Sn₃O₄In interstitial void.

2. Cu as described in claim 1 adulterates Sn₃O₄Gas sensitive, which is characterized in that the Sn₃O₄The thickness of nanometer sheet exists Between 10-25nm, diameter is between 1-4 μm.

3. a kind of Cu adulterates Sn₃O₄Gas sensitive preparation method, which comprises the steps of:

(1) then stannous chloride, citrate stirring soluble in water are added copper ion, stirred evenly, is designated as to abundant dissolution Solution A；

(2) aqueous slkali is slowly poured into the solution A, obtained solution is subjected to hydro-thermal reaction after stirring, it is cold after the completion But to room temperature, solid product is isolated, as Cu adulterates Sn₃O₄Gas sensitive.

4. Cu as claimed in claim 3 adulterates Sn₃O₄Gas sensitive preparation method, which is characterized in that in step (1), institute State stannous chloride, citrate (preferably sodium citrate), copper ion adding proportion be sequentially 1mmol:(2-3) mmol: (0.1-0.3) mmol, the dosage of water guarantee sufficiently to dissolve stannous chloride and citrate；

Preferably, in step (1), the addition of the copper ion is using the form of inorganic mantoquita, more preferably copper nitrate, chlorination Any one in copper, copper sulphate；

Preferably, in step (2), the aqueous slkali includes sodium hydroxide, any one in ammonium hydroxide；

Preferably, in step (2), the adding proportion of the aqueous slkali are as follows: stannous chloride: lye=1:0.5-1.2, molar ratio；

Preferably, in step (2), the condition of the hydro-thermal reaction are as follows: reacted 12-15 hours between 160-200 DEG C；

Preferably, in step (2), include the steps that washing solid product and being dried, specially with deionized water and Ethanol washing, it may be necessary to which repeatedly washing dries 12-14 hours at 60-80 DEG C after the completion of washing and adulterates Sn to get Cu₃O₄ Gas sensitive.

5. one kind adulterates Sn based on Cu₃O₄The formaldehyde gas sensor of gas sensitive, which is characterized in that the sensor is heater-type Structure, comprising: pedestal, ceramic tube, heater strip, circular metal electrode, gas sensitive and conducting wire；Wherein, the gas sensitive power The Cu doping Sn that benefit requires method described in 1 or 2 and/or claim 3 or 4 to prepare₃O₄Gas sensitive, in the ceramic tube It is provided with heater strip, and the both ends of heater strip extend respectively to the outside of two ports of ceramic tube；The circular metal electrode is It two, is covered on the outer surface of ceramic tube along the circumferential direction of ceramic tube, and two circular metal electrode interval settings；Institute It states gas sensitive to be arranged on the outer surface for being provided with the ceramic tube of circular metal electrode, and by ceramic tube and circular metal electrode It wraps up wherein；The both ends of the heater strip extended to outside ceramic tube are connect with pedestal；The conducting wire is four, is used for Circular metal electrode and pedestal are connected, wherein the corresponding one group of circular metal electrode of every two conducting wire, and two conducting wire settings exist One circular metal electrode two sides.

6. adulterating Sn based on Cu as claimed in claim 5₃O₄The formaldehyde gas sensor of gas sensitive, which is characterized in that described The material of ceramic tube is aluminium oxide；

Preferably, the material of the heater strip is Ni-Cr alloy, any one in Fe-Cr alloy；

Preferably, the material of the metal electrode is noble metal, such as any one in gold, platinum, palladium, silver；

Preferably, the material of the conducting wire is noble metal, such as any one in gold, platinum, palladium, silver.

7. adulterating Sn based on Cu as described in claim 5 or 6₃O₄The formaldehyde gas sensor of gas sensitive, which is characterized in that It is spiral shape that the heater strip, which is located at the part in ceramic tube,.

8. one kind adulterates Sn based on Cu₃O₄The preparation method of the formaldehyde gas sensor of gas sensitive, which is characterized in that including such as Lower step:

S1, Cu of any of claims 1 or 2 is adulterated into Sn₃O₄The preparation of method described in gas sensitive and/or claim 3 or 4 Cu adulterate Sn₃O₄Gas sensitive is prepared into finely dispersed paste；

S2, the paste in step S1 is uniformly coated on the ceramic pipe surface with a pair of metal electrodes, after natural drying It is dried；

S3, will it is dry in step S2 after ceramic tube in heating wire, metal electrode be respectively welded at the binding posts of six leg bases On, carry out aging then to get the formaldehyde gas sensor of heater-type structure.

9. adulterating Sn based on Cu as claimed in claim 8₃O₄The preparation method of the formaldehyde gas sensor of gas sensitive, it is special Sign is, in step S1, the paste the preparation method comprises the following steps: Cu is adulterated Sn₃O₄Gas sensitive powder and deionized water press matter Measure volume ratio 185-230:1-1.5 mixing, mg/ml；Then grinding and ultrasound, obtain finely dispersed paste, wherein described Milling time is 15-30min, ultrasonic time 30-60min；

Preferably, in step S2, the drying condition are as follows: the dry 10-12h between 60-80 DEG C；

Preferably, in step S2, the time of the aging is 22-25 hours.

10. Cu as claimed in claim 1 or 2 adulterates Sn₃O₄Gas sensitive and/or claim 3 or 4 described in method system Standby Cu adulterates Sn₃O₄Gas sensitive and/or such as described in any item formaldehyde gas sensors of claim 5-7 and in environment Application in gas-monitoring, industrial gasses analysis field.

Technical field

The present invention relates to gas sensor technical fields more particularly to a kind of Cu to adulterate Sn₃O₄Gas sensitive and its formaldehyde Gas sensor and preparation method, application.

Background technique

In background of invention, it is only intended to increase understanding of the overall background of the invention for disclosed information, without Necessarily it is considered as recognizing or imply that information composition has become in any form to show well known to persons skilled in the art There is technology.

With the emergence of artificial intelligence and Internet of Things information age, in the acquisition to information-transmission-processing chain, Sensor plays very important effect as the front end device for obtaining information in information technology chain.Society in recent years Rapid development that can be economic also gives our living environment band while bringing great riches and endless convenience to the mankind Some indelible damages are carried out.The exhaust gas generated in industrial processes, the tail gas of vehicular emission, house decoration generate The various air pollutions such as formaldehyde, the eyes and skin of people can be stimulated, make inflammatory eye skin allergy, moreover it is possible to stimulate exhaling for people Desorption system causes the diseases such as cough, asthma, or even can cause the fatal diseases such as lung cancer, cutaneum carcinoma, causes to people's health huge Big threat.So ensureing people's life wealth in order to inflammable and explosive, poisonous and hazardous gases various in real-time monitoring environment Safety is produced, gas sensor plays vital effect in the production and living of people.

Compared to separated using form and aspect, the equipment such as ultraviolet-uisible spectrophotometer and infrared absorption instrument sample gas Analysis, metal-oxide semiconductor (MOS) gas sensor have many advantages, such as that structure is simple, cheap, easy to use.It is generally used for The metal oxide materials of gas sensor have SnO₂、In₂O₃、Fe₂O₃、Co₃O₄, CuO etc., present inventors believe that common system The method of standby metal-oxide semiconductor (MOS), such as pulse laser deposition, magnetron sputtering, chemical vapor deposition etc., it usually needs complicated Operating procedure, and need expensive experimental facilities；And the gas sensor of single metal oxide materials, usually have The disadvantages of operating temperature height (200-400 DEG C), response is small, poor selectivity, slow response and resume speed.

Summary of the invention

For above-mentioned problem, the present invention is intended to provide a kind of Cu adulterates Sn₃O₄Gas sensitive and its formaldehyde gas sensing Device and preparation method, application.The present invention constructs Cu/Sn by metal ion mixing₃O₄Semiconductor material of composite metal oxide, The selectivity of metal-oxide semiconductor (MOS) gas sensor effectively can be enhanced at lower operating temperatures, accelerate sensor Response and resume speed, significantly improve sensor to test gas response.

The first object of the present invention is to provide Cu doping Sn₃O₄Gas sensitive and preparation method thereof.

The second object of the present invention is to provide and adulterates Sn based on Cu₃O₄The formaldehyde gas sensor of gas sensitive and its preparation Method.

The third object of the present invention is to provide the Cu doping Sn₃O₄Gas sensitive and its formaldehyde gas sensor and system The application of Preparation Method.

For achieving the above object, the invention discloses following technical proposals:

Firstly, the present invention discloses a kind of Cu doping Sn₃O₄Gas sensitive, comprising: Sn₃O₄Nanometer sheet and copper ion, it is described Sn₃O₄Nanometer sheet heap poststack forms three-dimensional flower-like structure, and the copper ion is present in Sn₃O₄Replace Sn among lattice₃O₄Lattice In part tin ion and Sn₃O₄In nanometer sheet and Sn₃O₄In interstitial void.

As further technical solution, the Sn₃O₄The thickness of nanometer sheet between 10-25nm, diameter 1-4 μm it Between.

Cu proposed by the present invention adulterates Sn₃O₄Gas sensitive the characteristics of be: (1) this Sn with flower-like structure₃O₄Gas Quick material is compared with ordinary granular or block-like oxide semiconductor material, and specific surface area is obviously improved, and is had micro- Pore structure can provide good absorption and diffusion path for gas, improve the response speed and resume speed of sensor.(2) By adulterating copper ion, Sn further reduced₃O₄The structure size of nanometer sheet increases the specific surface area of material, thus, into One step improves the response and response and resume speed of gas sensor.(3) doping metals copper ion can be such that material generates A large amount of atom defect, such defect are conducive to the absorption of oxygen molecule in air, increase the initial resistance of sensor, improve gas Quick response.(4) Cu ion in part is present in Sn₃O₄Interstitial void between, the Cu in these gaps is capable of providing a large amount of catalysis Active site is conducive to formaldehyde gas molecule and is chemically reacted on sense film surface, is also beneficial to the correlation of film surface Electronics transfer improves transducer sensitivity.

Secondly, the present invention provides a kind of Cu doping Sn₃O₄Gas sensitive preparation method, step are as follows:

(1) by stannous chloride, citrate stirring soluble in water to abundant dissolution, copper ion is then added, stirs evenly, It is designated as solution A；

(2) aqueous slkali is slowly poured into the solution A, obtained solution is subjected to hydro-thermal reaction after stirring, completed After be cooled to room temperature, isolate solid product, as Cu adulterates Sn₃O₄Gas sensitive.

As further technical solution, in step (1), the stannous chloride, citrate (such as sodium citrate), copper The adding proportion of ion is sequentially 1mmol:(2-3) mmol:(0.1-0.3) mmol, the dosage of water guarantees stannous chloride It is sufficiently dissolved with citrate.

As further technical solution, in step (1), form of the addition of the copper ion using inorganic mantoquita, example Such as common mantoquita of copper nitrate, copper chloride, copper sulphate.

As further technical solution, in step (2), the aqueous slkali includes sodium hydroxide, ammonium hydroxide etc., by adjusting The pH value of precursor solution, can control synthesis has the tin-oxide of different valence state of specific morphology.

As further technical solution, in step (2), the adding proportion of the lye are as follows: stannous chloride: lye=1: 0.5-1.2, molar ratio.

As further technical solution, in step (2), the condition of the hydro-thermal reaction are as follows: anti-between 160-200 DEG C It answers 12-15 hours.

As further technical solution, in step (2), include the steps that washing solid product and being dried, Specially use deionized water and ethanol washing, it may be necessary to which repeatedly washing dries 12-14 at 60-80 DEG C after the completion of washing Hour adulterates Sn to get Cu₃O₄Gas sensitive.

Again, the present invention discloses a kind of based on Cu doping Sn₃O₄The formaldehyde gas sensor of gas sensitive, the sensor are Heater-type structure comprising: pedestal, ceramic tube, heater strip, circular metal electrode, gas sensitive and conducting wire；Wherein, the gas The above-mentioned Cu of quick material adulterates Sn₃O₄Gas sensitive, heater strip, and the both ends difference of heater strip are provided in the ceramic tube Extend to the outside of two ports of ceramic tube；The circular metal electrode is two, is covered along the circumferential direction of ceramic tube On the outer surface of ceramic tube, and two circular metal electrode interval settings；The gas sensitive setting is being provided with endless metal On the outer surface of the ceramic tube of electrode, and ceramic tube and circular metal electrode are wrapped up wherein；The extension of the heater strip Both ends outside to ceramic tube are connect with pedestal；The conducting wire is four, for connecting circular metal electrode and pedestal, wherein often The corresponding one group of circular metal electrode of two conducting wires, and two conducting wires are arranged a circular metal electrode two sides.

For further technical solution, the material of the ceramic tube is aluminium oxide etc..

As further technical solution, the material of the heater strip is Ni-Cr alloy, any one in Fe-Cr alloy Kind.

As further technical solution, the material of the metal electrode is noble metal, such as gold, platinum, palladium, silver.

As further technical solution, the material of the conducting wire is noble metal, such as gold, platinum, palladium, silver.

As further technical solution, it is spiral shape that the heater strip, which is located at the part in ceramic tube,.In order to more Temperature needed for sensor function work is rapidly provided.

Thirdly, the present invention provides described based on Cu doping Sn₃O₄The preparation side of the formaldehyde gas sensor of gas sensitive Method includes the following steps:

S1, the Cu is adulterated into Sn₃O₄Gas sensitive is prepared into finely dispersed paste；

S2, the paste in step S1 is uniformly coated on the ceramic pipe surface with a pair of metal electrodes, dried in the air naturally It is dried after dry；

S3, will it is dry in step S2 after ceramic tube in heating wire, metal electrode be respectively welded at connecing for six leg bases On terminal, aging is carried out then to get the formaldehyde gas sensor of heater-type structure.

As further technical solution, in step S1, the paste the preparation method comprises the following steps: Cu is adulterated Sn₃O₄Air-sensitive Material powder is mixed with deionized water by mass volume ratio (mg/ml) 185-230:1-1.5, and then grinding and ultrasound, are divided Dissipate uniform paste, wherein the milling time is 15-30min, ultrasonic time 30-60min.

As further technical solution, in step S2, the drying condition are as follows: the dry 10-12h between 60-80 DEG C.

As further technical solution, in step S2, the time of the aging is 22-25 hours.

Finally, the present invention discloses the Cu doping Sn₃O₄Gas sensitive and preparation method thereof, Sn adulterated based on Cu₃O₄Gas The formaldehyde gas sensor of quick material and the application in the fields such as monitored gas environment, industrial gasses analysis.

Compared with prior art, the present invention achieve it is following the utility model has the advantages that

(1) Sn with flower-like structure that the present invention is adulterated with Cu₃O₄For formaldehyde gas sensor sensitive material, preparation Gas sensor at lower operating temperatures (160 DEG C), has big response, good formaldehyde gas selectivity and fast-response And resume speed, and can be effectively reduced experimental implementation complexity, save experimental cost.

(2) present invention reduces flower-shaped Sn by doping copper ion₃O₄The structure size of nanometer sheet, increases Sn₃O₄It receives The specific surface area of rice piece further improves the response and response and resume speed of gas sensor.

(3) present invention makes Sn by doping copper ion₃O₄A large amount of atom defect is generated in nanometer sheet, such defect has Conducive to the absorption of oxygen molecule in air, increase the initial resistance of sensor, improves air-sensitive response.

(4) present invention has part copper ion and is present in Sn by doping copper ion₃O₄Interstitial void between, and these Cu in gap is capable of providing a large amount of active site, is conducive to formaldehyde gas molecule on sense film surface and carries out chemistry Reaction is also beneficial to the associated electrical transfer of film surface, improves transducer sensitivity.

Detailed description of the invention

The accompanying drawings constituting a part of this application is used to provide further understanding of the present application, and the application's shows Meaning property embodiment and its explanation are not constituted an undue limitation on the present application for explaining the application.

Fig. 1 is to adulterate Sn based on Cu in the embodiment of the present invention 4₃O₄The structural representation of the formaldehyde gas sensor of gas sensitive Figure.

Fig. 2 is to adulterate Sn based on Cu in the embodiment of the present invention 1₃O₄The sectional view of the formaldehyde gas sensor of gas sensitive.

Fig. 3 is the Sn of difference Cu doping in the embodiment of the present invention 1₃O₄X-ray diffraction (XRD) figure of material.

Fig. 4 is the Sn of difference Cu doping in the embodiment of the present invention 1₃O₄Scanning of materials electron microscope (SEM) figure.

Fig. 5 is the Sn of difference Cu doping in the embodiment of the present invention 1₃O₄The sensor of material preparation is in different operating temperature Under at a temperature of 100ppm formaldehyde gas response test and different operating response and recovery time test result figure.

Fig. 6 is the Sn of difference Cu doping in the embodiment of the present invention 1₃O₄The sensor of material preparation is in 160 DEG C of operating temperatures Under to formaldehyde (1-300ppm) response test result figure of various concentration.

Fig. 7 is the Sn of difference Cu doping in the embodiment of the present invention 1₃O₄The sensor of material preparation is in 160 DEG C of operating temperatures Under to the selectivity test result figure of 100ppm gas with various.

Fig. 8 is the Sn of difference Cu doping in the embodiment of the present invention 1₃O₄The sensor of material preparation is in 160 DEG C of operating temperatures Under to the repeatability test of 100ppm formaldehyde gas and stability test figure in 40 days.

Attached drawing acceptance of the bid note respectively represents: 1- pedestal, 2- ceramic tube, 3- heater strip, 4- circular metal electrode, 5- air-sensitive material Material, 6- conducting wire.

Specific embodiment

It is noted that following detailed description is all illustrative, it is intended to provide further instruction to the present invention.Unless another It indicates, all technical and scientific terms used herein has usual with general technical staff of the technical field of the invention The identical meanings of understanding.

It should be noted that term used herein above is merely to describe specific embodiment, and be not intended to restricted root According to exemplary embodiments of the present invention.As used herein, unless the context clearly indicates otherwise, otherwise singular Also it is intended to include plural form, additionally, it should be understood that, when in the present specification using term "comprising" and/or " packet Include " when, indicate existing characteristics, step, operation, device, component and/or their combination.

As described in background, the common method for preparing metal-oxide semiconductor (MOS), such as pulse laser deposition, magnetic control Sputtering, chemical vapor deposition etc., it usually needs complicated operating procedure, and need expensive experimental facilities；And single gold Belong to the gas sensor of oxide material, usually have that operating temperature is high (200-400 DEG C), response is small, poor selectivity, response The disadvantages of slow with resume speed.Therefore, the invention proposes a kind of Cu to adulterate Sn₃O₄Gas sensitive and its formaldehyde gas sensing Device and preparation method, application are further illustrated the present invention now in conjunction with the drawings and specific embodiments.