The preparation method of benzene vapor detecting sensor sensitive material and gas sensor
Technical field
The present invention relates to the preparation method of a kind of benzene vapor detecting sensor sensitive material and gas sensor, function of dominant material, sensing technology and environmental monitoring technology field.
Background technology
Benzene is a kind of colourless, pleasantly sweet transparency liquid at normal temperatures, and has strong aromatic odor, and boiling point is 80.1 ℃.It is insoluble in water, is soluble in organic solvent, and itself is also widely used in the aspects such as the glue that uses in various building materialss and interior decoration, coating, leather and fur products as organic solvent.As everyone knows, benzene is very large to the harm of human body, and the Jiu Bei World Health Organization (WHO) is defined as strong carcinogen many years ago, so in monitoring of environmental, the concentration of benzene vapor is not only necessaryly, is also necessary.Many countries are an important indicator in Indoor Environment Detection using the detection of benzene vapor.The benzene vapor detecting sensor of having reported has quartzy crystallite balance detection method, photoelectric sensor, electrochemical sensor, LB film sensors, gas chromatography sensor, infrared detector and carbon nano tube sensor etc., but all exist some inevitable shortcomings, as huge in equipment, Portable belt not; Equipment is complicated, and maintenance cost is high; Organic Materials as Sensitive Elements is synthetic complicated, and productive rate is not high; Detect lower limit and do not reach Indoor Environment Detection standard; Carbon nano-tube preparation is complicated, noble metal decorated, causes material cost more high.
Summary of the invention
For the defect of prior art existence, the object of this invention is to provide the preparation method of a kind of benzene vapor detecting sensor sensitive material and gas sensor.Semiconductor gas sensor, due to advantages such as cost are low, easy to carry, low in energy consumption, sensitivity is high, is all people's study hotspot all the time.Develop outstanding benzene vapor detecting sensor and will make important contribution for environmental monitoring, scientific-technical progress and academic research, to ensureing that human health also has great meaning.
For achieving the above object, the present invention adopts following technical scheme:
A preparation method for benzene vapor detecting sensor sensitive material and gas sensor, has following preparation process and step:
A. SnO
2the preparation of nano material: with SnCl
45H
2o is raw material, is dissolved in the solution of making 0.05-0.2 mol/L in deionized water, 40 ℃ of water bath with thermostatic control magnetic agitation 30-50 minute, and it is 2-5 that dropping ammoniacal liquor is adjusted to pH; After centrifuging, obtain white gelatinous precipitate, then with deionized water and absolute ethyl alcohol centrifuge washing repeatedly, obtain gel particle after dry, 500 ℃ of annealing in process 2 hours, use agate mortar porphyrize, obtain SnO
2nano material;
B. SnO
2/ V
2o
5the preparation of nano composite material: by SnO
2: V
2o
5be that 99:1-4:1 grinds two kinds of nano materials evenly after mixing in mass ratio, at 600 ℃, solid phase reaction 2-3 hour obtains SnO
2/ V
2o
5nano composite material, i.e. benzene vapor detecting sensor sensitive material;
C. the preparation of benzene vapor detecting sensor gas sensor: first benzene vapor detecting sensor sensitive material is placed in to mortar, adds after a small amount of deionized water furnishing pasty state, be evenly coated on four angle plane substrates, solidify and process after 2-3 hour through 500 ℃; By thick film semiconducting gas sensor manufacture craft, gas sensor is welded, i.e. the welding of four electrical leads platinum filaments; After infrared lamp is dry, on agingtable, carry out aging, encapsulation, make benzene vapor detecting sensor gas sensor.
Compared with prior art, the benzene vapor detecting sensor sensitive material that prepared by the present invention and the advantage of gas sensor are as follows:
1, preparation technology is simple, environmental friendliness, and organic solvent-free, cost is low, is easy to realize mass production.
2, sensor gas sensor adopts a certain amount of V
2o
5with SnO
2the compound method of nano material improves gas sensitive to the sensitivity of benzene vapor and selectivity.
3, adopt thick-film type gas sensor element preparation technology, effectively reduce working temperature and the power consumption of element, and effectively reduced the volume of element, realized portability and low-power consumption.
Accompanying drawing explanation
Fig. 1 is SnO prepared by the inventive method
2the x-ray diffraction pattern of nano material.
Fig. 2 is SnO prepared by the inventive method
2the transmission electron microscope photo of nano material.
Fig. 3 is SnO prepared by the inventive method
2/ V
2o
5the x-ray diffraction pattern of nano composite material.
Fig. 4 is SnO prepared by the inventive method
2/ V
2o
5the transmission electron microscope photo of nano composite material.
Fig. 5 is the gas sensor that the makes response recovery curve figure to 50 ppm ethanol, methyl alcohol, acetone, formaldehyde, benzene and toluene.
Fig. 6 is the gas sensor that the makes response recovery curve figure to benzene vapor within the scope of 0.5 ppm to 200 ppm.
Embodiment
Below in conjunction with accompanying drawing, specific embodiments of the invention are described below:
embodiment mono-
In this example, the preparation method of benzene vapor detecting sensor sensitive material and gas sensor comprises the following steps:
A. SnO
2the preparation of nano material: with SnCl
45H
2o is raw material, is dissolved in the solution of making 0.05mol/L in deionized water, 40 ℃ of water bath with thermostatic control magnetic agitation 30 minutes, and dripping ammoniacal liquor, to be adjusted to pH be 2-5; After centrifuging, obtain white gelatinous precipitate, then with deionized water and absolute ethyl alcohol centrifuge washing repeatedly, obtain gel particle after dry, 500 ℃ of annealing in process 2 hours, use agate mortar porphyrize, obtain SnO
2nano material;
B. SnO
2/ V
2o
5the preparation of nano composite material: by SnO
2: V
2o
5be that 99:1 grinds two kinds of nano materials evenly after mixing in mass ratio, at 600 ℃, solid phase reaction obtains SnO for 2 hours
2/ V
2o
5nano composite material, i.e. benzene vapor sensor sensing material;
C. the preparation of benzene vapor detecting sensor gas sensor: first benzene vapor sensor sensing material is placed in to mortar, adds after a small amount of deionized water furnishing pasty state, be evenly coated in four angle plane substrates, solidify and process after 2 hours through 500 ℃; By thick film semiconducting gas sensor manufacture craft, gas sensor is welded to (i.e. the welding of four electrical leads platinum filaments); After infrared lamp is dry, carry out agingly on agingtable, encapsulation, makes benzene vapor and detects detecting sensor gas sensor.
embodiment bis-
In this example, the preparation method of benzene vapor detecting sensor sensitive material and gas sensor comprises the following steps:
A. SnO
2the preparation of nano material: with SnCl
45H
2o is raw material, is dissolved in the solution of making 0.1 mol/L in deionized water, 40 ℃ of water bath with thermostatic control magnetic agitation 40 minutes, and dripping ammoniacal liquor, to be adjusted to pH be 2-5; After centrifuging, obtain white gelatinous precipitate, then with deionized water and absolute ethyl alcohol centrifuge washing repeatedly, obtain gel particle after dry, 500 ℃ of annealing in process 2 hours, use agate mortar porphyrize, obtain SnO
2nano material;
B. SnO
2/ V
2o
5the preparation of nano composite material: by SnO
2: V
2o
5be that 9:1 grinds two kinds of nano materials evenly after mixing in mass ratio, at 600 ℃, solid phase reaction obtains SnO for 3 hours
2/ V
2o
5nano composite material, i.e. benzene vapor sensor sensing material;
C. the preparation of benzene vapor detecting sensor gas sensor: first benzene vapor sensor sensing material is placed in to mortar, adds after a small amount of deionized water furnishing pasty state, be evenly coated in four angle plane substrates, solidify and process after 2 hours through 500 ℃; By thick film semiconducting gas sensor manufacture craft, gas sensor is welded to (i.e. the welding of four electrical leads platinum filaments); After infrared lamp is dry, carry out agingly on agingtable, encapsulation, makes benzene vapor and detects detecting sensor gas sensor.
embodiment tri-
In this example, the preparation method of benzene vapor detecting sensor sensitive material and gas sensor comprises the following steps:
A. SnO
2the preparation of nano material: with SnCl
45H
2o is raw material, is dissolved in the solution of making 0.2 mol/L in deionized water, 40 ℃ of water bath with thermostatic control magnetic agitation 50 minutes, and dripping ammoniacal liquor, to be adjusted to pH be 2-5; After centrifuging, obtain white gelatinous precipitate, then with deionized water and absolute ethyl alcohol centrifuge washing repeatedly, obtain gel particle after dry, 500 ℃ of annealing in process 2 hours, use agate mortar porphyrize, obtain SnO
2nano material;
B. SnO
2/ V
2o
5the preparation of nano composite material: by SnO
2: V
2o
5be that 4:1 grinds two kinds of nano materials evenly after mixing in mass ratio, at 600 ℃, solid phase reaction obtains SnO for 3 hours
2/ V
2o
5nano composite material, i.e. benzene vapor sensor sensing material;
C. the preparation of benzene vapor detecting sensor gas sensor: first benzene vapor sensor sensing material is placed in to mortar, adds after a small amount of deionized water furnishing pasty state, be evenly coated in four angle plane substrates, solidify and process after 2 hours through 500 ℃; By thick film semiconducting gas sensor manufacture craft, gas sensor is welded to (i.e. the welding of four electrical leads platinum filaments); After infrared lamp is dry, carry out agingly on agingtable, encapsulation, makes benzene vapor and detects detecting sensor gas sensor.
The material list air-sensitive test result of seeking peace
The air-sensitive test that prepared material in embodiment bis-is carried out every sign and gas sensor is carried out, result is as follows:
The thing of gained monomer material and compound substance characterizes by X-ray diffraction and transmission electron microscope: in Fig. 1, the diffraction peak of X-ray diffraction is mainly tetragonal crystal system SnO
2(JCPDS 41-1445); On Fig. 2 transmission electron microscope photo, can find out prepared SnO
2for nano material, particle diameter is tens nanometers; X-ray diffraction pattern in Fig. 3 is found out the SnO that has tetragonal crystal system in compound substance
2(JCPDS 41-1445) and rhombic V
2o
5(JCPDS 41-1426) two-phase, illustrates that the two is compound substance, and can SnO on transmission electron microscope photo in Fig. 4
2/ V
2o
5nano composite material is comparatively uniform nano particle.
The air-sensitive test of gas sensor is carried out on WS-30A test macro: referring to Fig. 5, can find out that the gas sensor that embodiment obtains responds in recovery curve the multiple gases of 50 ppm, and the highest to the response of benzene vapor, and also corresponding release time is all very short.In Fig. 6, for variable concentrations benzene vapor, done special test, detected lower limit at 0.5-1ppm, responsiveness is along with the increase of benzene vapor concentration progressively increases, and corresponding release time is all in 10 seconds.