CN107673355A - A kind of gas sensing material for low-power-consumptiohigh-sensitivity high-sensitivity methane transducer - Google Patents

A kind of gas sensing material for low-power-consumptiohigh-sensitivity high-sensitivity methane transducer Download PDF

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CN107673355A
CN107673355A CN201710868601.8A CN201710868601A CN107673355A CN 107673355 A CN107673355 A CN 107673355A CN 201710868601 A CN201710868601 A CN 201710868601A CN 107673355 A CN107673355 A CN 107673355A
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titanium dioxide
gas sensing
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邬建敏
刘冬
栾春燕
孔洋波
马奔
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Hangzhou Jian Jian Technology Co Ltd
Zhejiang University ZJU
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Zhejiang University ZJU
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Abstract

The invention discloses a kind of gas sensing material for low-power-consumptiohigh-sensitivity high-sensitivity methane transducer, including one-dimensional silicon nanostructure and titanium dioxide shell, the sensing material includes following preparation process：(1) one-dimensional silicon nanostructure is prepared by metal Assisted Chemical Etching Process method.(2) titanium dioxide is made uniformly to modify on one-dimensional silicon nanostructure by one kind in drop coating, dip-coating, spin coating TiO 2 sol and physical vaporous deposition.(3) coreshell type structure of one-dimensional silicon nanostructure and titanium dioxide is formed by high annealing, the coreshell type structure is realized at room temperature to the resistance-type hypersensitive gas sensing of methane.The methane sensing material has that response sensitivity is high, restorative good, low in energy consumption, the advantages of being used with room temperature.

Description

A kind of gas sensing material for low-power-consumptiohigh-sensitivity high-sensitivity methane transducer
Technical field
The present invention relates to gas sensing field, and in particular to a kind of gas for low-power-consumptiohigh-sensitivity high-sensitivity methane transducer Sensing material.
Background technology
Methane gas is to deposit extensively in the life of people and energy source use as a kind of common flammable explosive gas , explosion limit is 5%-15% to methane in atmosphere, can make one to suffocate when it reaches finite concentration, and easily cause Coal-dust explosion.Therefore, for the generation prevented accident, it is timely monitored and alarm is very necessary.Deposit at present Methane transducer mainly to include catalytic combustion type, metal-oxide semiconductor (MOS) and infrared sensor etc. several.But metal The operating temperature that conductor oxidate and catalytic combustion type methane transducer need is higher, less stable, in inflammable and explosive atmosphere Enclose middle use will increase it is dangerous, simultaneously as needing extra heater to add the energy consumption of sensor.And infrared sensing Comparatively cost of manufacture is higher while energy consumption is larger for device.Therefore, the operating temperature of sensor is reduced, allows it can be in high-risk environment Middle work, and the energy consumption and cost of sensor are reduced, expanding its application field is all extremely necessary.
One-dimensional silicon nanostructure material, there is certain aspect ratio or oldered array, because it has larger specific surface area Got the attention with the physical property of uniqueness in many fields, for example, high density storage, sensor, micromechanics, Flied emission Device, lithium battery etc..Different from metal semiconductor oxide, one-dimensional silicon nanostructure material can produce to object gas at room temperature Raw response, and one-dimensional silicon nanostructure material surface is easy to be chemically modified, to improve gas sensing device performance and selection Property provides a variety of possibilities.The large-scale application of consumer field is to gas sensor in low cost, low-power consumption and small size side Face proposes higher requirement.One-dimensional silicon nanostructure material is reducing biosensor power consumption and size, simplified sensor construction, opened up It is significant to open up sensor application field etc..At present, one-dimensional silicon nanostructure material is used for hydrogen, ammonia, one The strong electrophilic such as nitrogen oxide, nitrogen dioxide or the detection of electron gas, because above-mentioned gas are on one-dimensional nano line Energy of adsorption significantly changes the carrier density of nano wire.However, current silicon nanowires is to more inert gas (such as methane Deng) detection be still difficult to.And sensitivity is still had not as gas sensing materials using simple silicon nanostructure material Enough height, the shortcomings of selectivity and stability difference, it have impact on the practicality based on silicon nanostructure material sensors.
One-dimensional silicon nanostructure and metal oxide are combined together by the present invention, in surface of silicon nanowires modified metal oxygen Compound, form coreshell type structure.Such composite nano-line produces sensitive resistance to methane gas at room temperature and rung without heating Should, thus available for making low-power consumption methane gas sensor.
The content of the invention
, should it is an object of the invention to provide a kind of gas sensing material for low-power-consumptiohigh-sensitivity high-sensitivity methane transducer Methane sensing material has that response sensitivity is high, restorative good, low in energy consumption, the advantages of being used with room temperature.
In order to solve the above-mentioned technical problem, adopt the following technical scheme that：
A kind of gas sensing material for low-power-consumptiohigh-sensitivity high-sensitivity methane transducer, including one-dimensional silicon nanostructure and two Titanium oxide shell, the sensing material include following preparation process：
(1) one-dimensional silicon nanostructure is prepared by metal Assisted Chemical Etching Process method.
(2) two are made by one kind in colloidal sol drop-coating, colloidal sol dip coating, colloidal sol spin-coating method and physical vaporous deposition Titanium oxide is uniformly modified on one-dimensional silicon nanostructure.
(3) coreshell type structure of one-dimensional silicon nanostructure and titanium dioxide, the hud typed knot are formed by high annealing Structure is realized at room temperature to the resistance-type hypersensitive gas sensing of methane.
Further, the one-dimensional silicon nanostructure includes nano wire, nano-pillar, porous nano line, porous nano post wherein At least one；The nano wire, nano-pillar, porous nano line, porous nano post are 10-40 μm in one-dimensional length.
Further, in the step (1), the metal Assisted Chemical Etching Process method prepares the mistake of one-dimensional silicon nanostructure Journey：At room temperature, one layer of blue film is pasted in silicon chip back side first, the area of blue film is identical with the area of silicon chip, avoids the back side from being carved Erosion, silicon chip are immersed in silver nitrate (AgNO3) and hydrofluoric acid (HF) mixed liquor at least 1min, until one layer of silverskin covers, then Silicon chip is placed on HF and H2O2Mixed solution in react 1-3h, take out and clean, be positioned in salpeter solution be dipped to it is not a half small When, the silver on surface is removed, is finally rinsed well with deionized water, and is dried up with nitrogen.
Further, the preparation method of the titanium dioxide shell includes colloidal sol drop-coating, colloidal sol dip coating, colloidal sol spin coating Method, physical vaporous deposition at least one therein.
Further, the process of titanium dioxide shell is prepared by TiO 2 sol drop-coating：A certain amount of two are taken at room temperature Titania sol solution drop coating is on one-dimensional silicon nanostructure surface and dries, and the colloidal sol amount of drop coating is relevant with silicon area, drop coating Amount be 0.4Lm-3Every time, repeat 4-5 times.
Further, the process of titanium dioxide shell is prepared by TiO 2 sol dip coating：One Dimension Silicon is received at room temperature Rice structural substract is put into 1min in TiO 2 sol solution, and taking-up is dried after being rinsed with isopropanol, repeats 1-3 times.
Further, the process of titanium dioxide shell is prepared by TiO 2 sol spin-coating method：50 μ L dioxies are taken at room temperature Change titanium colloidal sol, be added dropwise on one-dimensional silicon nanostructure surface, the first speed spin coating 10s with 500rpm, then revolved with 2000rpm speed 20s is applied, is repeated 2-3 times.
Further, the TiO 2 sol preparation method is：Isopropanol, water, acetic acid are stirred and mixed at room temperature, so Tetrabutyl titanate is added dropwise under agitation afterwards, isopropanol, water, the ratio of acetic acid are 5:0.805:1, the concentration of tetrabutyl titanate For 0.05-0.1mol/L, continue to stir 1h until bright milky colloidal sol is formed, and colloidal sol carried out being ultrasonically treated 0.5h small When more than.
Further, the one-dimensional silicon nanostructure and titanium dioxide (TiO2) compound formed by high annealing it is hud typed Structure, anneal environment are air atmosphere, and calcining heat is 450-600 DEG C, time 1-2h, heating rate not higher than 10 DEG C/ min。
Further, the process of titanium dioxide shell is prepared by physical vaporous deposition：On one-dimensional silicon nanostructure surface With magnetron sputtering or plasma sputtering layer of metal titanium, titanium dioxide shell is formed by high-temperature oxydation；Or utilize electron beam Titanium dioxide layer is deposited on one-dimensional silicon nanostructure surface in evaporation, and layer of titanium metal thickness range is in 5-200nm.
Further, the coreshell type structure is a kind of resistance-type hypersensitive gas sensing material, can be believed by monitoring current Number change at room temperature to methane carry out super sensitivity detection, application voltage range is 1-3V, and lowest detection is limited to 20ppm, work( Consumption is in microwatt rank.
Due to using above-mentioned technical proposal, the invention has the advantages that：
1st, one-dimensional silicon nanostructure and titanium dioxide (TiO2) compound coreshell type structure has the higher ratio of silicon nanowires concurrently The characteristic of surface area and titanium dioxide adsorption of oxygen and methane, provide not only a large amount of gas passages, while also improve oxygen ginseng Gas-sensitive property with the conditions of, so as to substantially increase sensitivity；
2nd, resistance-type sensing material of the invention uses at normal temperatures, greatly reduces senor operating temperature and energy Consumption；
3rd, material manufacture craft of the invention is simple, and cost is low, and the senser element that the material is formed has higher sensitive Spend, be preferably restorative, service life is longer, is expected to promotion one-dimensional silicon nanostructure answering in terms of room temperature methane transducer With.
Brief description of the drawings
The invention will be further described below in conjunction with the accompanying drawings：
Fig. 1 is silicon nanometer and SEM the and TEM comparison diagrams of silicon nanowires and titanium dioxide compound；
Image (1a) and (1b) are respectively the SEM vertical views and sectional view of simple silicon nanowires；
Image (1d) and (1e) are respectively the SEM vertical views and sectional view of silicon nanowires and titanium dioxide compound；
Image (1c) and (1f) are respectively the TEM figures of simple silicon nanowires and silicon nanowires and titanium dioxide compound；
Fig. 2 is silicon nanowires and the XRD phenograms of titanium dioxide compound and simple titanium dioxide crystal；
Fig. 3 is the real-time response graph of a relation of silicon nanowires and titanium dioxide compound to methane gas；
Image (3a) and (3b) are respectively the real-time side view that p-type silicon nano wire and titanium dioxide compound respond to methane And response and the response relation figure of gas concentration；
Image (3c) and (3d) are respectively the real-time side view that n-type silicon nano wire and titanium dioxide compound respond to methane And response and the response relation figure of gas concentration；
Fig. 4 is the repeated response diagram of silicon nanowires and titanium dioxide compound to methane gas；
Image (4a) is the repeated response diagram that p-type silicon nano wire and titanium dioxide compound respond to methane；
Image (4b) is the repeated response diagram that n-type silicon nano wire and titanium dioxide compound respond to methane.
Embodiment
Technical scheme is described further with reference to Figure of description：
Because methane is non-polar gas, the absorption in One Dimension Silicon nanometer is difficult to change carrier density, because almost Electrical response can not be produced.And the energy gap of titanium dioxide is larger, it is typically only capable at high temperature to produce methane gas Electrical response.But one-dimensional silicon nanostructure has good electric conductivity, and huge specific surface area at room temperature, also simultaneously It is easy to carry out the construction of hetero-junctions (pn, nn) with other metal semiconductor oxides.Metal oxide there is catalysis to make gas With can effectively to some, more inert gases carry out sensing response.Therefore one-dimensional silicon nanostructure and metal are aoxidized Thing combines, and can realize that gas sensing at room temperature responds by the construction of knot.
According to above-mentioned mechanism, the present invention adopts the following technical scheme that：One kind is used for hypersensitive low power consumption resistance formula methane gas Preparation method and its sensing capabilities test of body sensor material.Methods described includes：(1) metal Assisted Chemical Etching Process method is passed through (MACE) one-dimensional silicon nanostructure is prepared；(2) colloidal sol drop-coating, colloidal sol dip coating, colloidal sol spin-coating method and physical vapor are passed through One kind in sedimentation makes titanium dioxide uniformly modify on one-dimensional silicon nanostructure；(3) nucleocapsid is formed by high annealing Type structure, in the case where applying constant voltage, realize the resistance-type oversoul to methane at room temperature by the change of monitoring current signal Quick gas sensing.
In the present invention, one-dimensional silicon nanostructure material is prepared by metal Assisted Chemical Etching Process method, silicon chip used is n Type or p-type silicon, resistivity are 1-10 Ω cm.First one layer of blue film, the area of blue film and the area of silicon chip are pasted in silicon chip back side It is identical；Silicon chip is immersed in silver nitrate (AgNO3) and hydrofluoric acid (HF) mixed liquor at least 1min, until one layer of silverskin covers, The thickness of silverskin is relevant with soak time；Then take out silicon chip and with deionized water rinsing 3-4 times, silicon chip is then placed on HF And H2O2Solution in react 1-3h, take out and clean, be positioned over the silver that immersion in aqueous solution of nitric acid removes surface, finally spend from Sub- water is rinsed well, nitrogen drying.Reaction is carried out at room temperature.
In the present invention, the pattern of one-dimensional silicon nanostructure, including diameter, length, thickness and silverskin sedimentary condition and quarter Erosion condition is relevant.Fig. 1 a and 1b be respectively by metal Assisted Chemical Etching Process method prepare simple silicon nanowires SEM overlook and Sectional view, interior illustration are partial enlarged drawings, can prepare uniform silicon nanowire array by this method, nanowire diameter is about 50nm。
In the present invention, described one-dimensional nano structure, including nano wire, nano-pillar, porous nano line, porous nano Post, or at least one therein, nano wire, nano-pillar, porous nano line, porous nano post are 10-40 μm in one-dimensional length.
In the present invention, described TiO 2 sol preparation method is：Mix isopropanol at room temperature, water, acetic acid, Then tetrabutyl titanate is added dropwise under agitation, isopropanol, water, the ratio of acetic acid are 5:0.805:1, tetrabutyl titanate it is dense Spend for 0.05-0.1mol/L, continue to stir 1h until bright milky colloidal sol is formed, and colloidal sol is subjected to supersound process 0.5h More than hour.
In the present invention, described TiO 2 sol drop-coating is prepared in titanium dioxide shell, is taken with micropipettor A certain amount of TiO 2 sol solution drop coating is on one-dimensional silicon nanostructure surface and dries, drying temperature be 60 DEG C, drop coating it is molten Glue amount is relevant with silicon area, generally 0.4Lm-3Every time, repeat 4-5 times.
In the present invention, described TiO 2 sol dip coating is prepared in titanium dioxide shell, at room temperature by One Dimension Silicon Nanostructured substrate is put into 1min in TiO 2 sol solution, and taking-up is dried after being rinsed with isopropanol, and drying temperature is 60 DEG C, Repeat 1-3 times.The method obtains the titanium dioxide shell similar with TiO 2 sol drop-coating.
In the present invention, described TiO 2 sol drop-coating and dip coating are prepared in titanium dioxide shell, One Dimension Silicon Nanostructured and titanium dioxide (TiO2) compound by high annealing formed coreshell type structure, anneal environment is air atmosphere, Calcining heat is 450-600 DEG C, time 1-2h, and heating rate is not higher than 10 DEG C/min.Fig. 1 d and 1e are respectively silicon nanowires Overlooked with the SEM of titanium dioxide compound and sectional view, interior illustration are partial enlarged drawings, can by TiO 2 sol drop-coating To modify one layer of uniform titanium dioxide in surface of silicon nanowires, the thickness of titanium dioxide shell is about 100-200nm (Fig. 1 f).
In the present invention, the titanium dioxide shell that prepared by described TiO 2 sol drop-coating and dip coating, its thickness The number of amount, drop coating with drop coating and the number of immersion, time are relevant, and on the whole, amount is more, and number is more, titanium dioxide Shell is thicker.
In the present invention, described another kind prepares titanium dioxide shell method：Physical vaporous deposition prepares titanium dioxide Titanium shell, in the physical vapour deposition (PVD) layer of metal titanium such as one-dimensional silicon nanostructure surface magnetron sputtering or plasma sputtering, Titanium dioxide shell is formed by high-temperature oxydation layer of titanium metal, or is deposited using electron beam evaporation on one-dimensional silicon nanostructure surface Titanium dioxide layer, layer of titanium metal thickness range are relevant with the condition sputtered in 5-200nm, thickness.
In the present invention, it is a kind of resistance-type to form one-dimensional silicon nanostructure and titanium dioxide core shell mould structure, the structure Hypersensitive gas sensing material, without being heated to material, in the case where applying constant voltage, voltage range 1-3V, preferably 1V, pass through The change of monitoring current signal can carry out super sensitivity detection to methane at room temperature.It is 100-200mL/ to detect methane gas flow Min, preferably 100mL/min, air are carrier gas, and gas concentration excursion is 20-200ppm.
In the present invention, the methane gas prepared based on one-dimensional silicon nanostructure and titanium dioxide core shell mould structure Sensor, lowest detection are limited to 20ppm, and power consumption is in microwatt rank.
Pass through a kind of one-dimensional silicon nanostructure prepared by the above method and titanium dioxide (TiO2) compound gas sensing Material, there is coreshell type structure, the senser element formed using the material is low in energy consumption, can carry out oversoul to methane at room temperature Quick detection, and this method technique is simple, and cost is cheap.
With reference to specific embodiment, the present invention is described further.
[embodiment 1] drop-coating prepares silicon nanowires and titanium dioxide compound
1. the preparation of TiO 2 sol：5mL isopropanols are taken, 0.805mL water, 1mL acetic acid is stirred and mixed, then in play 0.18mL tetrabutyl titanates are added dropwise under strong stirring, continue to stir 1h until bright milky colloidal sol is formed.Then should Solution ultrasound 30min.
2. silicon nanowires is prepared by metal Assisted Chemical Etching Process method:P-type or n-type silicon chip are immersed in 0.004M nitric acid Silver (AgNO3) and 4.8M hydrofluoric acid (HF) mixed liquor in 2min cover until one layer of silverskin, then take out silicon chip and spend from Sub- water is rinsed 3-4 times, and silicon chip then is placed on into HF (4.8M)：H2O2(30%)=10：When one section is reacted in 1 (v/v) solution Between, take out and clean, be positioned in aqueous solution of nitric acid (v/v=1:1) immersion removes the silver on surface, is finally done with deionized water rinsing Only, nitrogen dries up.
3. by the colloidal sol drop coating in step 1 to the surface of silicon nanowires in step 2
4. pair silicon nanowires is sintered 2h for 450 DEG C with titanium dioxide compound in air atmosphere, 5 DEG C/min is kept. Fig. 2 is the XRD phenograms of silicon nanowires and titanium dioxide compound and simple titanium dioxide crystal, and the method obtains preferably Titanium dioxide crystal.
5. doing electrode with metal probe, resistive memory gas sensor is built.At room temperature, it is homemade using laboratory Air-sensitive test system, in the case where applying 1V constant voltages, is examined with Devince By Dynamic Gas Ration Method by the change of monitoring current signal to methane Survey.
6. it is 200mL/min to detect methane gas flow, air is carrier gas, and gas concentration excursion is 30-200ppm. Fig. 3 is the real-time response graph of a relation of silicon nanowires and titanium dioxide compound to various concentrations methane gas, and Fig. 3 a and 3b distinguish The real-time detection figure responded for p-type silicon nano wire and titanium dioxide compound to methane and response and the response of gas concentration are closed System's figure, Fig. 3 c and 3d are respectively the real-time detection figure and response that n-type silicon nano wire and titanium dioxide compound respond to methane With the response relation figure of gas concentration.As can be seen that during methane gas is detected, silicon nanowires divides for the test more than Typical p-type and n-type silicon nano wire property are not shown, i.e. p-type conductivity declines, and n-type conductivity rises.And can be with Find out when methane concentration is 30-120ppm, there is certain linear relationship, when concentration is more than 120ppm, engender balance It is stable.Fig. 4 is the repeated response diagram of silicon nanowires and titanium dioxide compound to methane gas, and Fig. 4 a are p-type silicon nano wire The repeated response diagram responded with titanium dioxide compound to methane, Fig. 4 b are n-type silicon nano wire and titanium dioxide compound pair The repeated response diagram of methane response, by these tests it can be seen that the material has good repeatability.
[embodiment 2] dip coating prepares silicon nanowires and titanium dioxide compound
1. the preparation of TiO 2 sol：5ml isopropanols are taken, 0.805ml water, 1ml acetic acid is stirred and mixed, then in play 0.18ml tetrabutyl titanates are added dropwise under strong stirring, continue to stir 1h until bright milky colloidal sol is formed.Then should Solution ultrasound 30min.
2. silicon nanowires is prepared by metal Assisted Chemical Etching Process method:N-type silicon chip is immersed in 0.004M silver nitrate (AgNO3) and 4.8M hydrofluoric acid (HF) mixed liquor in 2min cover until one layer of silverskin, then take out silicon chip and use deionization Water is rinsed 3-4 times, and silicon chip then is placed on into HF (4.8M)：H2O2(30%)=10：When one section is reacted in 1 (v/v) solution Between, take out and clean, be positioned in aqueous solution of nitric acid (v/v=1:1) immersion removes the silver on surface, is finally done with deionized water rinsing Only, nitrogen dries up.
3. the one-dimensional silicon nanowires substrate in step 2 is put into 1min in the TiO 2 sol solution in step 1, take out Dry, repeat 1-3 times, by controlling time of immersion and number controlled modification amount after being rinsed with isopropanol.
4. pair silicon nanowires carries out calcining 2h for 450 DEG C with titanium dioxide compound in air atmosphere, programming rate keeps 5 ℃/min。
[embodiment 3] spin-coating method prepares silicon nanowires and titanium dioxide compound
1. the preparation of TiO 2 sol：5ml isopropanols are taken, 0.805ml water, 1ml acetic acid is stirred and mixed, then in play 0.18ml tetrabutyl titanates are added dropwise under strong stirring, continue to stir 1h until bright milky colloidal sol is formed.Then should Solution ultrasound 30min.
2. silicon nanowires is prepared by metal Assisted Chemical Etching Process method:N-type silicon chip is immersed in 0.004M silver nitrate (AgNO3) and 4.8M hydrofluoric acid (HF) mixed liquor in 2min cover until one layer of silverskin, then take out silicon chip and use deionization Water is rinsed 3-4 times, and silicon chip then is placed on into HF (4.8M)：H2O2(30%)=10：When one section is reacted in 1 (v/v) solution Between, take out and clean, be positioned in aqueous solution of nitric acid (v/v=1:1) immersion removes the silver on surface, is finally done with deionized water rinsing Only, nitrogen dries up.
3. the colloidal sol in step 1 is spun to the surface of silicon nanowires in step 2, the first speed spin coating 10s with 500rpm, Again with 2000rpm speed spin coating 20s, pass through adjustment control spin-coating time and number controlled modification amount.
4. pair silicon nanowires carries out calcining 2h for 450 DEG C with titanium dioxide compound in air atmosphere, programming rate keeps 5 ℃/min。
[embodiment 4] physical vaporous deposition prepares silicon nanowires and titanium dioxide compound
1. silicon nanowires is prepared by metal Assisted Chemical Etching Process method:N-type silicon chip is immersed in 0.004M silver nitrate (AgNO3) and 4.8M hydrofluoric acid (HF) mixed liquor in 2min cover until one layer of silverskin, then take out silicon chip and use deionization Water is rinsed 3-4 times, and silicon chip then is placed on into HF (4.8M)：H2O2(30%)=10：When one section is reacted in 1 (v/v) solution Between, take out and clean, be positioned in aqueous solution of nitric acid (v/v=1:1) immersion removes the silver on surface, is finally done with deionized water rinsing Only, nitrogen dries up.
2. one-dimensional silicon nanostructure surface magnetron sputtering or plasma sputtering layer of metal titanium in step 1, lead to Cross high-temperature oxydation and form titanium dioxide shell, layer of titanium metal thickness range is in 5-200nm.
3. pair silicon nanowires is calcined with Titanium compound in air atmosphere, calcining heat is 450-600 DEG C, when Between be 1-2h, heating rate is not higher than 10 DEG C/min.
The specific embodiment of the present invention is these are only, but the technical characteristic of the present invention is not limited thereto.It is any with this hair Based on bright, to solve essentially identical technical problem, essentially identical technique effect is realized, made ground simple change, etc. With replacement or modification etc., all it is covered by among protection scope of the present invention.

Claims (10)

1. a kind of gas sensing material for low-power-consumptiohigh-sensitivity high-sensitivity methane transducer, including one-dimensional silicon nanostructure and dioxy Change titanium shell, it is characterised in that：The sensing material includes following preparation process：
(1) one-dimensional silicon nanostructure is prepared by metal Assisted Chemical Etching Process method；
(2) titanium dioxide is made by one kind in colloidal sol drop-coating, colloidal sol dip coating, colloidal sol spin-coating method and physical vaporous deposition Titanium is equably modified on one-dimensional silicon nanostructure；
(3) coreshell type structure of one-dimensional silicon nanostructure and titanium dioxide is formed by high annealing, the coreshell type structure is real Now at room temperature to the resistance-type hypersensitive gas sensing of methane.
2. a kind of gas sensing material for low-power-consumptiohigh-sensitivity high-sensitivity methane transducer according to claim 1, it is special Sign is：The one-dimensional silicon nanostructure includes nano wire, nano-pillar, porous nano line, porous nano post therein at least one Kind；The nano wire, nano-pillar, porous nano line, porous nano post are 10-40 μm in one-dimensional length.
3. a kind of gas sensing material for low-power-consumptiohigh-sensitivity high-sensitivity methane transducer according to claim 1 or 2, its It is characterised by：In the step (1), the metal Assisted Chemical Etching Process method prepares the process of one-dimensional silicon nanostructure：In room Under temperature, one layer of blue film is pasted in silicon chip back side first, the area of blue film is identical with the area of silicon chip, avoids the back side from being etched, silicon chip It is immersed in silver nitrate (AgNO3) and hydrofluoric acid (HF) mixed liquor at least 1min, until one layer of silverskin covers, then silicon chip is put Put in HF and H2O2Mixed solution in react 1-3h, take out and clean, be positioned in salpeter solution and be dipped to not a half hour, remove The silver on surface, is finally rinsed well with deionized water, and is dried up with nitrogen.
4. a kind of gas sensing material for low-power-consumptiohigh-sensitivity high-sensitivity methane transducer according to claim 1, it is special Sign is：The process of titanium dioxide shell is prepared by TiO 2 sol drop-coating：Take a certain amount of titanium dioxide molten at room temperature Peptization drop-coated is on one-dimensional silicon nanostructure surface and dries, and the colloidal sol amount of drop coating is relevant with silicon area, and the amount of drop coating is 0.4L·m-3Every time, repeat 4-5 times.
5. a kind of gas sensing material for low-power-consumptiohigh-sensitivity high-sensitivity methane transducer according to claim 1, it is special Sign is：The process of titanium dioxide shell is prepared by TiO 2 sol dip coating：At room temperature by one-dimensional silicon nanostructure base Piece is put into 1min in TiO 2 sol solution, and taking-up is dried after being rinsed with isopropanol, repeats 1-3 times.
6. a kind of gas sensing material for low-power-consumptiohigh-sensitivity high-sensitivity methane transducer according to claim 1, it is special Sign is：The process of titanium dioxide shell is prepared by TiO 2 sol spin-coating method：50 μ L TiO 2 sols are taken at room temperature, It is added dropwise on one-dimensional silicon nanostructure surface, the first speed spin coating 10s with 500rpm, then the speed spin coating 20s with 2000rpm, weight It is multiple 2-3 times.
A kind of 7. gas sensing for low-power-consumptiohigh-sensitivity high-sensitivity methane transducer according to claim 1 or 4 or 5 or 6 Material, it is characterised in that：The TiO 2 sol preparation method is：Isopropanol, water, acetic acid are stirred and mixed at room temperature, Then tetrabutyl titanate is added dropwise under agitation, isopropanol, water, the ratio of acetic acid are 5:0.805:1, tetrabutyl titanate it is dense Spend for 0.05-0.1mol/L, continue to stir 1h until bright milky colloidal sol is formed, and colloidal sol is subjected to supersound process 0.5h More than hour.
A kind of 8. gas sensing material for low-power-consumptiohigh-sensitivity high-sensitivity methane transducer according to claim 1 or 4 or 5 Material, it is characterised in that：The one-dimensional silicon nanostructure forms coreshell type structure with titanium dioxide compound by high annealing, moves back Fire environment is air atmosphere, and calcining heat is 450-600 DEG C, time 1-2h, and heating rate is not higher than 10 DEG C/min.
9. a kind of gas sensing material for low-power-consumptiohigh-sensitivity high-sensitivity methane transducer according to claim 1, it is special Sign is：The process of titanium dioxide shell is prepared by physical vaporous deposition：Splashed on one-dimensional silicon nanostructure surface with magnetic control Penetrate or plasma sputtering layer of metal titanium, pass through high-temperature oxydation and form titanium dioxide shell；Or using electron beam evaporation one Silicon nanostructure surface evaporation titanium dioxide layer is tieed up, layer of titanium metal thickness range is in 5-200nm.
10. a kind of gas sensing material for low-power-consumptiohigh-sensitivity high-sensitivity methane transducer according to claim 1, it is special Sign is：The coreshell type structure is a kind of resistance-type hypersensitive gas sensing material, can pass through the change of monitoring current signal Super sensitivity detection is carried out to methane at room temperature, application voltage range is 1-3V, and lowest detection is limited to 20ppm, and power consumption is in microwatt Rank.
CN201710868601.8A 2017-09-22 2017-09-22 A kind of gas sensing material for low-power-consumptiohigh-sensitivity high-sensitivity methane transducer Pending CN107673355A (en)

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