CN1513807A

CN1513807A - Nano-crystalline erbium oxide-tin oxide powder material and its preparation method and use

Info

Publication number: CN1513807A
Application number: CNA021602050A
Authority: CN
Inventors: 李来风; 傅绍云
Original assignee: Technical Institute of Physics and Chemistry of CAS
Current assignee: Technical Institute of Physics and Chemistry of CAS; RIKEN Institute of Physical and Chemical Research
Priority date: 2002-12-31
Filing date: 2002-12-31
Publication date: 2004-07-21
Anticipated expiration: 2022-12-31
Also published as: CN1232473C

Abstract

A nano-crystal erbium oxide-tin oxide powder used for preparing the gas-sensitive element to detect CO gas is prepared from SnCl4.5H2O and Er(NO3)3.5H2O through adding distilled water to become solution, proportionally mixing, dripping ammonia water to obtain white deposit, washing with distilled water, filtering, baking and calcining.

Description

Nanocrystalline Erbium trioxide-stannic oxide powder material and its production and use

Invention field

The invention belongs to and be used to stannic oxide powder material of making gas sensor and its production and use, particularly a kind of nanocrystalline Erbium trioxide-stannic oxide powder material and its production and use

Background technology

Tindioxide is the present the widest gas sensor of turnout maximum application face in the world as the gas sensor material always.Because the gas sensor with this material preparation has following generally acknowledged advantage: 1) element resistance changes and the gas concentration exponent function relation, and in low strength range, this variation is fairly obvious, it is very suitable therefore micro-light concentration gas to be detected; 2) physical and chemical stability of tin dioxide material is good, and corrosion fatigue life is long; 3) detection is reversible to SnO 2 gas-sensitive element to gas, and absorption and parsing time weak point; 4) prepared component structure is simple, and cost is low, the reliability height, and vibration resistance and impact property are good; 5) gas detects and does not need complex facilities, and gas to be measured can directly change into signal by the variation of gas sensor resistance value, and change in resistance is big, just can realize with ball bearing made using.

The preparation method of tin dioxide powder is very ripe, mainly contains four kinds of methods: 1) with pink salt such as Sn (NO ₃) ₄Add thermal decomposition and obtain tin ash; 2) heating of metal tin obtains tin ash in air; 3) utilize gaseous state tin and plasma oxygen reaction tin ash processed; 4) precipitation method utilize butter of tin or stannous chloride solution to add ammoniacal liquor tin ash processed.

Because the tin ash powder is more thin, its specific area is more big, and is just more responsive to gas to be measured, thus the superfine tin dioxide powder of high dispersive be prepared into the key of making good gas sensor.More than four kinds of methods the most suitable with the powder of precipitator method preparation at aspects such as granularity, technology, costs, be widely adopted.

Although tindioxide is very outstanding as gas sensor, but people still wish to find on this basis better material, therefore researcher adopts that the doping other materials is in the hope of improving its sensitivity (sensitivity is to define with the ratio of the aerial resistance of material divided by resistance in gas to be measured) in tindioxide in recent ten years, and the big more sensitivity of its numerical value is high more.People have studied and added Pd, Pt, Ag in tin ash,, Au, etc. metal simple-substance or add Sb ₂O ₃, ZrO ₂, Y ₂O ₃, wait compound, performance or increase is perhaps good to the more unadulterated tin ash of certain gas sensitization degree.Preparation for metal simple-substance, general employing certain granules degree (micron order) metal powder and SnO2 powder carry out ball milling and synthesize, for other oxide compounds, mix and adopt ball milling or chemical coprecipitation, the benefit that adopts chemical coprecipitation method be mix more even, the powder particle size that obtains is little, specific surface area is big, therefore for the material of this method preparation of same composition material to gas sensitization degree height, what the novel material of contrast material of the present invention and invention adopted all is chemical coprecipitations.

Summary of the invention

The present invention seeks in tin ash, to add Er ₂O ₃, contain Er so that a kind of nanocrystalline erbium oxide-tin oxide powder material to be provided ₂O ₃

Another object of the present invention is to provide a kind of this nanocrystalline erbium oxide-tin oxide powder material for preparing to contain Er ₂O ₃The preparation method;

A further object of the present invention is to provide a kind of this nanocrystalline erbium oxide-tin oxide powder material to contain Er ₂O ₃Purposes;

The technical scheme that realizes the object of the invention is as follows:

Nanocrystalline Erbium trioxide provided by the invention-stannic oxide powder material is characterized in that, in this powder body material, the weight part proportioning of Erbium trioxide content and stannic oxide content is 3-5: 100; Its granularity is the 20-40 nanometer.

Nanocrystalline Erbium trioxide provided by the invention-stannic oxide powder preparation methods, its step is as follows:

1) the employing chemical purity is 98% SnCl ₄.5H ₂O and chemical purity are 99.99% Er (NO ₃) ₃.5H ₂O is as raw material, with they difference adding distil water wiring solution-formings;

2) press SnCl ₄The aqueous solution and Er (NO ₃) ₃The weight portion proportioning of erbium oxide and tin oxide is 1-5 in the aqueous solution: 100 proportioning is mixed, and with the speed dropping ammonia of per minute 0.5-1.5ml, obtains white depositions then, the sediment that obtains is carried out distilled water repeatedly clean, filter; Obtain white object; Step 2) describedly the sediment that obtains is carried out three distilled water repeatedly cleans, filters.

3) with calcining after the white object oven dry that obtains, promptly obtain faint yellow Erbium trioxide of the present invention-stannic oxide powder material; The described bake out temperature of step 3) is 50-100 ℃; The described calcining temperature of step 3) is 450-600 ℃;

The purposes of nanocrystalline Erbium trioxide provided by the invention-stannic oxide powder material is that this powder body material is used to prepare the gas sensor to the CO sensitivity, and detected gas concentration is greater than 50ppm.Nanocrystalline Erbium trioxide provided by the invention-stannic oxide powder material is characterized in that the weight part proportioning of its Erbium trioxide content and stannic oxide content is 1-5: 100; Its granularity is the 20-40 nanometer.

Preparation method of the present invention is simple, and is easy to operate, prepared Er ₂O ₃-SnO ₂Powder body material can be used for making gas sensor, the susceptibility that prepared gas sensor detects CO gas more not the high 2-3 of doping stannic oxide material doubly, especially its addition is the Er of 3% percentage by weight ₂O ₃-SnO ₂The susceptibility of powder body material is best.

Description of drawings:

Accompanying drawing 1 is doping Different Weight percentage Er ₂O ₃SnO ₂Material and unadulterated SnO ₂The susceptibility of material in CO gas

Accompanying drawing 2 is the 3% weight ratio Er that mixes ₂O ₃, Y ₂O ₃, ZrO ₂, Sb ₂O ₃SnO2 and the SnO that do not mix ₂The susceptibility of material in CO gas

Embodiment

Embodiment 1

Prepare a kind of Er with method of the present invention ₂O ₃-SnO ₂Powder body material, its step is as follows:

1) adopts chemical pure SnCl ₄.5H ₂O (purity 98%) and Er (NO ₃) ₃.5H ₂O (purity 99.99%) is as raw material, with they difference adding distil water wiring solution-formings;

2) press SnCl ₄The aqueous solution and Er (NO ₃) ₃The weight portion proportioning of erbium oxide and tin oxide is that 1: 100 proportioning is mixed in the aqueous solution, with the speed dropping ammonia of per minute 1.5ml, obtains white depositions then, cleans and filters with 0.2 micron filter paper with distilled water; And repeatedly carry out three times, obtain white alloy;

The white alloy that 3) will obtain is put into electric furnace to calcine 4 hours under 600 ℃ of air atmospheres 100 ℃ of lower oven dry 10 hours then, namely obtains faint yellow invention Er ₂O ₃-SnO ₂Powder body material, its Er ₂O ₃With SnO ₂The weight portion proportioning be 1: 100.

Embodiment 2

2) press SnCl ₄The aqueous solution and Er (NO ₃) ₃The weight portion proportioning of erbium oxide and tin oxide is that 3: 100 proportioning is mixed in the aqueous solution, with the speed dropping ammonia of per minute 1ml, obtains white depositions then, cleans and filters with 0.2 micron filter paper with distilled water; And repeatedly carry out three times, obtain white alloy;

The white alloy that 3) will obtain is put into electric furnace to calcine 4 hours under 600 ℃ of air atmospheres 100 ℃ of lower oven dry 10 hours then, namely obtains faint yellow Er ₂O ₃-SnO ₂Powder body material, its Er ₂O ₃With SnO ₂The weight portion proportioning be 3: 100.

Embodiment 3

2) press SnCl ₄The aqueous solution and Er (NO ₃) ₃The weight portion proportioning of erbium oxide and tin oxide is that 5: 100 proportioning is mixed in the aqueous solution, with the speed dropping ammonia of per minute 0.5ml, obtains white depositions then, cleans and filters with 0.2 micron filter paper with distilled water; And repeatedly carry out three times, obtain white alloy;

The white alloy that 3) will obtain is put into electric furnace to calcine 4 hours under 600 ℃ of air atmospheres 100 degrees centigrade of lower oven dry 10 hours then, namely obtains faint yellow Er ₂O ₃-SnO ₂Powder body material, its Er ₂O ₃With SnO ₂The weight portion proportioning be 5: 100.

Er with above embodiment preparation ₂O ₃-SnO ₂Powder body material and pure SnO ₂Powder adopts conventional method for printing screen to prepare the thick film sensing element at the white stone substrate, with elargol four spun golds is fixed on and obtains four electrodes on the thick film, measures then in air and resistance in different CO concentration atmosphere, and its sensitivity parameter is seen accompanying drawing 1;

Accompanying drawing 1 is the Er of above-described embodiment preparation ₂O ₃-SnO ₂The gas sensor that powder body material is made and use pure SnO ₂The gas sensor that powder body material is made is to the contrast schematic diagram of the susceptibility of CO; Can be drawn to draw a conclusion by figure: 1) doping weight ratio is 1%Er ₂O ₃-SnO ₂Material the susceptibility of CO gas is compared with pure SnO2 increase 2) the doping weight ratio is 3%Er ₂O ₃-SnO ₂Material the susceptibility of CO gas compared with pure SnO2 improved 2-3 doubly, especially to low concentration CO sensitivity 3) the doping weight ratio is 5%Er ₂O ₃-SnO ₂Material the susceptibility of CO gas compared with pure SnO2 improved 1-3 doubly, relatively more responsive when CO content is high.

Accompanying drawing 2 is the Er of above-described embodiment preparation ₂O ₃-SnO ₂The gas sensor that powder body material is made and the miserable assorted Y that has ₂O ₃, Sb ₂O ₃, ZrO ₂The SnO of compound ₂The gas sensor that powder body material is made is to the comparison schematic diagram of the susceptibility of CO; Can be drawn to draw a conclusion by figure: 1) with pure SnO ₂Material is compared susceptibility and is increased 2) and doping Er ₂O ₃Material compare poor, especially when the CO gas content is low.3) doping 2-5Er ₂O ₃Material best, also be the composition range that we will protect.

In a word, powder body material of the present invention is as the detection of CO gas, especially the best results during detection when following to low levels 300ppm.

Claims

1, a kind of nanocrystalline Erbium trioxide-stannic oxide powder material is characterized in that, in this powder body material, the weight part proportioning of Erbium trioxide content and stannic oxide content is 1-5: 100; Its granularity is the 20-40 nanometer.

2, the described nanocrystalline Erbium trioxide of a kind of claim 1-stannic oxide powder preparation methods, its step is as follows:

2) press SnCl ₄The aqueous solution and Er (NO ₃) ₃The weight portion proportioning of erbium oxide and tin oxide is 1-5 in the aqueous solution: 100 proportioning is mixed, and with the speed dropping ammonia of per minute 0.5-1.5ml, obtains white depositions then, the sediment that obtains is carried out distilled water repeatedly clean, filter; Obtain white object;

3) with calcining after the white object oven dry that obtains, promptly obtain faint yellow Erbium trioxide of the present invention-stannic oxide powder material.

3, by the described nanocrystalline Erbium trioxide-stannic oxide powder preparation methods of claim 2, it is characterized in that the described bake out temperature of step 3) is 50-100 ℃.

4, by the described nanocrystalline Erbium trioxide-stannic oxide powder preparation methods of claim 2, it is characterized in that the described calcining temperature of step 3) is 450-600 ℃.

5, by the described nanocrystalline Erbium trioxide-stannic oxide powder preparation methods of claim 2, it is characterized in that step 2) describedly the throw out that obtains is carried out three distilled water repeatedly clean, filter.

6, the purposes of the described nanocrystalline Erbium trioxide of a kind of claim 1-stannic oxide powder material is characterized in that, is used to prepare the gas sensor to the CO sensitivity.