JP2008209249A - Oxygen gas detection element, and nanowire for oxygen gas detection element - Google Patents

Oxygen gas detection element, and nanowire for oxygen gas detection element Download PDF

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JP2008209249A
JP2008209249A JP2007046461A JP2007046461A JP2008209249A JP 2008209249 A JP2008209249 A JP 2008209249A JP 2007046461 A JP2007046461 A JP 2007046461A JP 2007046461 A JP2007046461 A JP 2007046461A JP 2008209249 A JP2008209249 A JP 2008209249A
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nanowire
oxygen gas
detection element
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Nobuyuki Nishi
信之 西
Takeshi Soshiro
健 十代
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National Institute of Natural Sciences
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    • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
    • G01N27/04—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance
    • G01N27/12—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of a solid body in dependence upon absorption of a fluid; of a solid body in dependence upon reaction with a fluid, for detecting components in the fluid
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    • G01N27/127—Composition of the body, e.g. the composition of its sensitive layer comprising nanoparticles

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device capable of detecting adsorption oxygen gas molecules by electrical conductivity characteristics change at room temperature. <P>SOLUTION: This oxygen gas detection element equipped with a nanowire, including a CU core and a carbon-coating layer formed so as to coat the CU core, is constituted so that the nanowire shows an adsorption/desorption action to oxygen gas at a room temperature, and that the oxygen gas is detected through the adsorption/desorption action of the oxygen gas. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

本発明は、銅アセチリドのナノ構造体を活用した酸素ガス分子の吸着を電気伝導特性として感知するセンサー装置に関するものである。   The present invention relates to a sensor device that senses adsorption of oxygen gas molecules as an electric conduction characteristic using a copper acetylide nanostructure.

酸素ガスを検出するセンサーは、多種多様な動作原理および動作環境のものが提案されている（例えば、R. Ramamoorthy et al. Journal of Materials Science vol.38 year 2003 pages 4271-4282）。酸素ガス分子の検出を電気伝導特性（抵抗率）で感知するものが、装置の簡便さとしては有利であるが、分子が吸脱着・化学反応を起こすには、かなりの高温を必要とする。一方、室温で動作可能なセンサーとしては、水中の溶解ガスを電気分解により感知するものと、発光分子の失効過程を利用するものが挙げられるが、どちらも装置が大掛かりとなってしまう欠点をもつため簡便な実用に対しては問題を有する。
R. Ramamoorthy et al. Journal of Materials Science vol.38 year 2003 pages 4271-4282 Sensors for detecting oxygen gas have been proposed with various operating principles and operating environments (for example, R. Ramamoorthy et al. Journal of Materials Science vol. 38 year 2003 pages 4271-4282). The detection of oxygen gas molecules by means of electric conduction characteristics (resistivity) is advantageous as the simplicity of the apparatus, but a considerably high temperature is required for molecules to cause adsorption / desorption / chemical reaction. On the other hand, sensors that can be operated at room temperature include sensors that detect dissolved gas in water by electrolysis and sensors that use the deactivation process of luminescent molecules, both of which have the disadvantage of making the device large. Therefore, there is a problem for simple practical use.
R. Ramamoorthy et al. Journal of Materials Science vol.38 year 2003 pages 4271-4282

本発明は、室温において電気伝導特性変化により吸着酸素ガス分子を検知できる装置を提供することを目的とする。   An object of this invention is to provide the apparatus which can detect adsorption | suction oxygen gas molecule | numerator by electrical conductivity characteristic change at room temperature.

上記目的を達成すべく、本発明は、
Ｃｕコアと、このＣｕコアを被覆するようにして形成された炭素被覆層とを含むナノワイヤを具え、
室温において酸素ガスに対して脱吸着作用を呈し、前記酸素ガスの前記脱吸着作用を通じて前記酸素ガスを検出するように構成したことを特徴とする、酸素ガス検出素子に関する。 In order to achieve the above object, the present invention provides:
Comprising a nanowire comprising a Cu core and a carbon coating layer formed so as to cover the Cu core;
The present invention relates to an oxygen gas detection element configured to exhibit a desorption action on oxygen gas at room temperature and to detect the oxygen gas through the desorption action of the oxygen gas.

また、本発明は、
Ｃｕコアと、このＣｕコアを被覆するようにして形成された炭素被覆層とを含むナノワイヤを具えることを特徴とする、酸素ガス検出素子用ナノワイヤに関する。 The present invention also provides:
The present invention relates to a nanowire for an oxygen gas detection element, comprising a nanowire including a Cu core and a carbon coating layer formed so as to cover the Cu core.

本発明者は、上記目的を達成すべく鋭意検討を実施した。その結果、銅アセチリド分子を自己組織化によりナノワイヤへと結晶成長させる方法を見出し、この銅アセチリドナノワイヤを出発物質として熱処理により炭素層被覆銅ナノワイヤ（ナノケーブル）に変換することに成功していた。そして、熱処理後の炭素層被覆銅ナノワイヤを含む銅と炭素の混合物の電気伝導特性を測定したところ、酸素分子の吸脱着により抵抗値が変化することを発見した。また、分子の吸脱着は室温で可逆的進行することを見出した。   The present inventor has intensively studied to achieve the above object. As a result, the inventors have found a method for crystal growth of copper acetylide molecules into nanowires by self-organization, and succeeded in converting the copper acetylide nanowires to carbon layer-coated copper nanowires (nano-cables) by heat treatment using the copper acetylide nanowires as a starting material. And when the electrical conduction characteristic of the mixture of copper and carbon containing the carbon layer covering copper nanowire after heat processing was measured, it discovered that resistance value changed by adsorption / desorption of an oxygen molecule. It was also found that the adsorption / desorption of molecules proceeds reversibly at room temperature.

したがって、上述のような炭素層被覆銅ナノワイヤの上記室温での脱吸着反応を利用することによって、上記ナノワイヤを室温において酸素ガスを検出するセンサー装置として利用可能であることを見出し、本発明をするに至った。   Therefore, the present invention finds that the nanowire can be used as a sensor device for detecting oxygen gas at room temperature by utilizing the desorption reaction at room temperature of the carbon layer-coated copper nanowire as described above. It came to.

なお、本発明における「室温」とは、広義には酸素の脱吸着に対して特に従来のような加熱操作を行わないことを意味し、特には上記酸素ガス検出素子の使用環境におけるその環境温度を意味するものである。   The term “room temperature” in the present invention means, in a broad sense, that no conventional heating operation is performed for desorption of oxygen, and in particular, the ambient temperature in the environment where the oxygen gas detection element is used. Means.

銅と炭素複合材料との混合物である上記ナノワイヤによれば、室温において様々な分子の吸脱着を進行させることができる。一般に室温などで容易に吸脱着できるのは、物理吸着過程による分子の吸着であり、物理吸着過程では、分子と吸着体との相互作用が小さく、電気伝導特性が大きく変化することは、ほとんど観測されない。   According to the nanowire which is a mixture of copper and a carbon composite material, adsorption / desorption of various molecules can proceed at room temperature. In general, adsorption and desorption that can be easily adsorbed and desorbed at room temperature is the adsorption of molecules by the physical adsorption process, and in the physical adsorption process, it is almost observed that the interaction between the molecule and the adsorbent is small and the electric conduction characteristics change greatly Not.

しかしながら、本発明の上記ナノワイヤでは、ナノ構造物の特異な吸着構造のため、物理吸着のような弱い酸素分子吸着状態においても、ナノ構造物から酸素分子への可逆的な電子移動、即ち構造体へのホール注入を起こすことにより大きく電気伝導度が上昇する。この事は、熱起電力計測結果からも確認された。ゆえに、本発明において、室温でも動作可能な酸素ガスセンサーを得ることができた。   However, since the nanowire of the present invention has a unique adsorption structure of the nanostructure, reversible electron transfer from the nanostructure to the oxygen molecule, that is, the structure even in a weak oxygen molecule adsorption state such as physical adsorption. Electrical conductivity is greatly increased by injecting holes. This was also confirmed from the thermoelectromotive force measurement results. Therefore, in the present invention, an oxygen gas sensor operable at room temperature has been obtained.

以上説明したように、本発明によれば、室温において電気伝導特性変化により吸着酸素ガス分子を検知できる装置、いわゆる酸素ガス検出素子を提供することができる。   As described above, according to the present invention, it is possible to provide a device capable of detecting adsorbed oxygen gas molecules based on a change in electric conduction characteristics at room temperature, a so-called oxygen gas detection element.

以下、本発明のその他の特徴及び利点について、発明を実施するための最良の形態について説明する。   Hereinafter, the best mode for carrying out the invention will be described with respect to other features and advantages of the present invention.

（ナノワイヤ）
本発明の酸素ガス検出素子は、Ｃｕコアと、このＣｕコアを被覆するようにして形成された炭素被覆層とを含むナノワイヤを基本的な構成要素として含む。このナノワイヤは、その直径が５ｎｍ〜１０ｎｍであることが好ましい。前記ナノワイヤがこのような微細な大きさを有することによって、前記ナノワイヤが室温において酸素ガス（分子）をより多く物理的に吸着することができるとともに、その結果、酸素分子との物理的吸着を通じて酸素分子への電子移動及びナノワイヤへのホール注入を良好に行うことができるようになる。したがって、前記ナノワイヤは酸素ガス検出素子としてより効果的に機能するようになる。 (Nanowire)
The oxygen gas detection element of the present invention includes, as a basic constituent element, a nanowire including a Cu core and a carbon coating layer formed so as to cover the Cu core. The nanowire preferably has a diameter of 5 nm to 10 nm. Since the nanowire has such a fine size, the nanowire can physically adsorb more oxygen gas (molecules) at room temperature, and as a result, oxygen can be absorbed through physical adsorption with oxygen molecules. Electron transfer to molecules and hole injection to nanowires can be performed well. Accordingly, the nanowire functions more effectively as an oxygen gas detection element.

また、同様の観点から、前記ナノワイヤの長さは０．１μｍ〜１μｍであることが好ましい。   From the same viewpoint, the length of the nanowire is preferably 0.1 μm to 1 μm.

なお、上記構成及び大きさのナノワイヤは、以下に詳述するような製造方法に起因して必然的に得ることができる。   The nanowire having the above-described configuration and size can be inevitably obtained due to a manufacturing method as described in detail below.

（ナノワイヤの製造）
次に、上記ナノワイヤの製造方法について説明する。最初に塩化銅(Ｉ)(ＣｕＣｌ)を準備し、反応容器中に入れたアンモニア水中に溶解させる。その後、必要に応じて前記アンモニア水中に溶解している酸素分子及び前記反応容器中の空気を追い出すために、希ガス、例えばアルゴンガスなどを用いてバブリングする。このバブリングに要する時間は前記容器の体積などに依存するが、通常は数十分のオーダである。 (Manufacture of nanowires)
Next, the manufacturing method of the said nanowire is demonstrated. First, copper (I) chloride (CuCl) is prepared and dissolved in ammonia water placed in a reaction vessel. Thereafter, in order to drive out oxygen molecules dissolved in the ammonia water and air in the reaction vessel as necessary, bubbling is performed using a rare gas such as argon gas. The time required for this bubbling depends on the volume of the container, but is usually on the order of several tens of minutes.

次いで、前記アンモニア水に対して希ガス、例えばアルゴンガスなどで所定濃度に希釈したアセチレンガスを接触させ、前記塩化銅(Ｉ)と反応させる。このような反応を通じて、水溶液中のＣｕ＋イオンを元に以下の反応式で示すようなＣ２Ｃｕ２なる組成を有し、その全体に亘って均一な組成を有するナノワイヤ中間体が自己組織的に形成される。
２Ｃｕ＋＋Ｃ２Ｈ２→Ｃ２Ｃｕ２（ナノワイヤ中間体）＋２Ｈ＋ Subsequently, acetylene gas diluted to a predetermined concentration with a rare gas such as argon gas is brought into contact with the ammonia water, and reacted with the copper (I) chloride. Through such a reaction, a nanowire intermediate having a composition of C 2 Cu 2 as shown in the following reaction formula based on Cu + ions in an aqueous solution and having a uniform composition over the whole is self-organizing. Formed.
2Cu + + C 2 H 2 → C 2 Cu 2 (nanowire intermediate) + 2H +

なお、アセチレンガスの希釈度合いは、例えばアセチレンガスが数％のオーダとなるようにする。また、アセチレンガスの接触時間（反応時間）は、数時間のオーダである。   The degree of dilution of the acetylene gas is, for example, such that the acetylene gas is on the order of several percent. The contact time (reaction time) of acetylene gas is on the order of several hours.

また、前記アセチレンガスは前記アンモニア水に対して０．３ｍｌ／分以下の割合で接触させる。アセチレンガスの量が０．３ｍｌ／分よりも大きいと、前記アセチレンガスの接触によって得るナノワイヤ中間体の結晶性が低下し、例えばアモルファス化する。したがって、目的とする、Ｃｕコアと、このＣｕコアを被覆するようにして形成された炭素被覆層とを含むナノワイヤを得ることができない場合がある。但し、アセチレンガスの量の下限は０．０１ｍｌ／分とする。これよりもアセチレンガスの量が少ないと上記ナノワイヤ中間体を自己組織的に得ることができない場合がある。   The acetylene gas is brought into contact with the ammonia water at a rate of 0.3 ml / min or less. When the amount of acetylene gas is larger than 0.3 ml / min, the crystallinity of the nanowire intermediate obtained by the contact with the acetylene gas is lowered, for example, it becomes amorphous. Therefore, there may be a case where the target nanowire including the Cu core and the carbon coating layer formed so as to cover the Cu core cannot be obtained. However, the lower limit of the amount of acetylene gas is 0.01 ml / min. If the amount of acetylene gas is less than this, the nanowire intermediate may not be obtained in a self-organizing manner.

次いで、上述のようのようにして得たナノワイヤ中間体を非酸化性雰囲気下に配置し、所定温度に加熱してアニール処理を施す。この際、均一な組成のナノワイヤ中間体は、それを構成するＣ２Ｃｕ２がＣ（炭素）とＣｕ（銅）とに分離し、Ｃｕをコア層としてその外表面に炭素層が被覆してなる、本発明の構成のナノワイヤが得られる。 Next, the nanowire intermediate obtained as described above is placed in a non-oxidizing atmosphere, and is annealed by heating to a predetermined temperature. At this time, the nanowire intermediate of uniform composition is formed by separating C 2 Cu 2 constituting it into C (carbon) and Cu (copper), and coating the outer surface with a carbon layer using Cu as a core layer. Thus, a nanowire having the structure of the present invention is obtained.

なお、上記非酸化性雰囲気としては、希ガス雰囲気や減圧雰囲気などの酸素成分が前記ナノワイヤの作製に影響を与えないような条件が選ばれる。特に、減圧雰囲気の場合、その圧力は１ｍTorr以下とすることが好ましい。また、前記アニール処理は５０℃以上、好ましくは８０℃程度で行うことが好ましい。さらに、前記アニール処理は２段階で行うことができ、例えば最初に５０−７０℃程度で前段階加熱した後、８０℃付近の温度で加熱処理を行うようにすることができる。   The non-oxidizing atmosphere is selected so that oxygen components such as a rare gas atmosphere and a reduced-pressure atmosphere do not affect the production of the nanowire. In particular, in a reduced pressure atmosphere, the pressure is preferably 1 mTorr or less. The annealing treatment is preferably performed at 50 ° C. or higher, preferably about 80 ° C. Furthermore, the annealing treatment can be performed in two stages. For example, after the first stage heating is first performed at about 50 to 70 ° C., the heating treatment can be performed at a temperature around 80 ° C.

以下、実施例に基づいて本発明を具体的に説明する。   Hereinafter, the present invention will be specifically described based on examples.

最初に、２００ｍｌのセパラブルフラスコに５％アンモニア水１００ｍｌを採り、塩化銅（I）１．０ｇを加え、溶解させた。次いで、前記フラスコ内の空気およびアンモニア水に溶けている酸素分子を追い出すため、前記フラスコ内にアルゴンガスを投入し、３０分間、バブリングした。次いで、攪拌しているフラスコ内にアルゴンにより希釈した１％のアセチレンガスを水溶液上方から前記フラスコ内のアルゴンを介して間接的に溶液と反応させた。この際、アセチレンガスはアルゴンで希釈した状態で５〜３０ｍｌ／分の流量で３時間反応させた。この反応により、得られた反応溶液は銅アンミン錯体の青色から茶褐色に変化し沈殿が生じた。   First, 100 ml of 5% aqueous ammonia was taken into a 200 ml separable flask, and 1.0 g of copper (I) chloride was added and dissolved. Subsequently, in order to drive out oxygen molecules dissolved in the air and aqueous ammonia in the flask, argon gas was introduced into the flask and bubbled for 30 minutes. Next, 1% acetylene gas diluted with argon was reacted with the solution indirectly from above the aqueous solution via argon in the flask in the stirring flask. At this time, the acetylene gas was reacted at a flow rate of 5 to 30 ml / min for 3 hours in a state diluted with argon. As a result of this reaction, the resulting reaction solution changed from the blue color of the copper ammine complex to brown, and precipitation occurred.

次いで、前記沈殿物を濾過により溶液から分離して試験内に採り、減圧及び脱水処理を実施した。次いで、前記沈殿物をＳＥＭ及びＴＥＭで観察したところ、長さ約１μｍ、直径５−１０ｎｍのナノワイヤ（中間体）であることが判明した。また、前記ナノワイヤ（中間体）をＸＲＤによって調べたところ、Ｃ２Ｃｕ２なる結晶構造を呈することが判明した。 Next, the precipitate was separated from the solution by filtration and taken into the test, and decompression and dehydration were performed. Next, when the precipitate was observed with SEM and TEM, it was found to be a nanowire (intermediate) having a length of about 1 μm and a diameter of 5 to 10 nm. Further, when the nanowire (intermediate) was examined by XRD, it was found to exhibit a crystal structure of C 2 Cu 2 .

次いで、真空下電気炉あるいは所定の容器中に溶媒分散した浴を準備し、前記電気炉あるいは前記浴中において、前記ナノワイヤ中間体を５０℃から７０℃程度で前段階加熱した後、８０℃付近の温度で加熱処理を行なった。この加熱処理により、前記ナノワイヤでは、銅元素と炭素元素への分離が進行し、銅ナノワイヤ（直径２nm）を炭素層で被覆した銅ナノワイヤを形成した。なお、このナノワイヤの構成についてもＴＥＭによって確認した。   Next, an electric furnace under vacuum or a bath in which a solvent is dispersed in a predetermined container is prepared. In the electric furnace or the bath, the nanowire intermediate is heated in the previous stage at about 50 ° C. to 70 ° C., and then around 80 ° C. The heat treatment was performed at a temperature of. By this heat treatment, separation of the copper element and the carbon element proceeded in the nanowire, and a copper nanowire in which the copper nanowire (diameter 2 nm) was covered with a carbon layer was formed. The configuration of the nanowire was also confirmed by TEM.

次いで、前記銅ナノワイヤを以下に示す評価に供するために、ハンドプレス等によりタブレット状に加圧成型した。   Subsequently, in order to use for the evaluation shown below, the copper nanowire was press-molded into a tablet shape by a hand press or the like.

図１は、上述のようにして得た銅ナノワイヤの電気伝導変化のグラフである。図１から明らかなように、成型したタブレットを窒素雰囲気下に存在させると低い電気伝導度（高抵抗）を示し、酸素ガスに暴露すると高い電気伝導度（低抵抗）を示した。この変化は、 繰り返し測定可能であり、酸素分子が室温において吸脱着していることが判明した。   FIG. 1 is a graph of the change in electrical conductivity of copper nanowires obtained as described above. As is apparent from FIG. 1, when the molded tablet was present in a nitrogen atmosphere, it exhibited low electrical conductivity (high resistance), and when exposed to oxygen gas, it exhibited high electrical conductivity (low resistance). This change can be measured repeatedly, and it was found that oxygen molecules adsorbed and desorbed at room temperature.

図２は、上述のようにして得た銅ナノワイヤを窒素ガス１００％、１気圧の環境から窒素ガス０．５気圧、酸素ガス０．５気圧（酸素５０％）の状態に変化させたときの電流量の変化を示すグラフである。なお、印加電圧は１Ｖとした。図２から明らかなように、酸素ガスの吸着が進むにつれ、電流値が増大し、前記銅ナノワイヤに対して酸素分子が吸着することが分かる。但し、応答時間が若干長いが、これはタブレットが０．２ ｍｍ程度の厚みを持つために、酸素吸着が飽和するまでに多少の時間を要するためであると考えられる。   FIG. 2 shows a state in which the copper nanowire obtained as described above is changed from an environment of nitrogen gas 100% and 1 atm to a state of nitrogen gas 0.5 atm and oxygen gas 0.5 atm (oxygen 50%). It is a graph which shows the change of electric current amount. The applied voltage was 1V. As can be seen from FIG. 2, as the adsorption of oxygen gas proceeds, the current value increases, and oxygen molecules are adsorbed to the copper nanowires. However, although the response time is slightly long, this is considered to be because it takes some time for oxygen adsorption to saturate because the tablet has a thickness of about 0.2 mm.

上記応答時間を短縮化するためには、銅ナノワイヤを櫛形電極等に厚さ数μmの薄膜として密着させれば、応答時間の大幅な短縮が期待される。しかし、現状のタブレット状においても、初期の数分間の電流値変化の勾配から、飽和状態を予測することが可能であり、十分な実用速度を持っていると言える。さらに、この飽和状態では、酸素分子の吸脱着が化学反応的に平衡状態になっているとみられ、飽和・平衡状態での電気伝導特性を求めることができる。   In order to shorten the response time, if the copper nanowire is brought into close contact with a comb-shaped electrode or the like as a thin film having a thickness of several μm, it is expected that the response time is significantly shortened. However, even in the current tablet form, it is possible to predict the saturation state from the gradient of the current value change in the initial few minutes, and it can be said that it has a sufficient practical speed. Further, in this saturated state, the adsorption / desorption of oxygen molecules is considered to be in an equilibrium state in a chemical reaction, and the electric conduction characteristics in the saturation / equilibrium state can be obtained.

図３は、上記銅ナノワイヤにおいて、全圧が１気圧の条件で酸素の分圧を０％から１００％まで変化させた場合の電流量の変化を示すグラフである。なお、この場合の印加電圧も１Ｖとしている。電流量の変化は、Langmuirの吸着等温式を用いて説明することができ、図３より酸素濃度を決定する検量線として利用可能である。また、Langmuirの吸着等温式の特性として、低濃度において大きく吸着量が変化する。さらに、酸素ガスの存在により最大１０倍程度も電流値が変化するため、前記銅ナノワイヤは、低濃度域での超高感度な酸素センサーとして機能することが判明した。   FIG. 3 is a graph showing changes in the amount of current when the partial pressure of oxygen is changed from 0% to 100% under the condition that the total pressure is 1 atm in the copper nanowire. In this case, the applied voltage is also 1V. The change in the amount of current can be described using the Langmuir adsorption isotherm, and can be used as a calibration curve for determining the oxygen concentration from FIG. In addition, as an adsorption isotherm characteristic of Langmuir, the amount of adsorption varies greatly at low concentrations. Furthermore, since the current value is changed up to about 10 times due to the presence of oxygen gas, it has been found that the copper nanowire functions as an ultra-sensitive oxygen sensor in a low concentration region.

一方、上記の電気伝導性の変化は、窒素ガス・アルゴンガスでは全く観測されなかった。
以上、具体例を挙げながら発明の実施の形態に基づいて本発明を詳細に説明してきたが、本発明は上記内容に限定されるものではなく、本発明の範疇を逸脱しない限りにおいてあらゆる変形や変更が可能である。 On the other hand, the above-mentioned change in electrical conductivity was not observed at all with nitrogen gas / argon gas.
As described above, the present invention has been described in detail based on the embodiments of the present invention with specific examples. However, the present invention is not limited to the above contents, and all modifications and changes are made without departing from the scope of the present invention. It can be changed.

本発明の銅ナノワイヤの電気伝導変化を示すグラフである。It is a graph which shows the electrical conduction change of the copper nanowire of this invention. 本発明の銅ナノワイヤを窒素ガス１００％、１気圧の環境から窒素ガス０．５気圧、酸素ガス０．５気圧（酸素５０％）の状態に変化させたときの電流量の変化を示すグラフである。It is a graph which shows the change of the amount of electric current when the copper nanowire of this invention is changed into the state of nitrogen gas 0.5 atmosphere, oxygen gas 0.5 atmosphere (oxygen 50%) from nitrogen gas 100% and 1 atmosphere. is there. 本発明の銅ナノワイヤを、全圧が１気圧の条件で酸素の分圧を０％から１００％まで変化させた場合の電流量の変化を示すグラフである。It is a graph which shows the change of the electric current amount when changing the partial pressure of oxygen from 0% to 100% of the copper nanowire of the present invention under the condition that the total pressure is 1 atm.

Claims (13)

Ｃｕコアと、このＣｕコアを被覆するようにして形成された炭素被覆層とを含むナノワイヤを具え、
室温において酸素ガスに対して脱吸着作用を呈し、前記酸素ガスの前記脱吸着作用を通じて前記酸素ガスを検出するように構成したことを特徴とする、酸素ガス検出素子。 Comprising a nanowire comprising a Cu core and a carbon coating layer formed so as to cover the Cu core;
An oxygen gas detection element configured to exhibit a desorption action on oxygen gas at room temperature, and to detect the oxygen gas through the desorption action of the oxygen gas. 前記ナノワイヤの直径が５ｎｍ〜１０ｎｍであることを特徴とする、請求項１に記載の酸素ガス検出素子。   The oxygen gas detection element according to claim 1, wherein the nanowire has a diameter of 5 nm to 10 nm. 前記ナノワイヤの長さが０．１μｍ〜１μｍであることを特徴とする、請求項1又は２に記載の酸素ガス検出素子。   3. The oxygen gas detection element according to claim 1, wherein the nanowire has a length of 0.1 μm to 1 μm. 前記酸素ガスの検出は、前記酸素ガスの前記脱吸着作用を通じた電気伝導特性の変化として検出することを特徴とする、請求項１〜３のいずれか一に記載の酸素ガス検出素子。   The oxygen gas detection element according to any one of claims 1 to 3, wherein the detection of the oxygen gas is detected as a change in electrical conduction characteristics through the desorption action of the oxygen gas. 前記ナノワイヤは、水溶液中のＣｕ＋イオンを原料とし、この原料に対してアセチレンガスを接触させて結晶性のナノワイヤ中間体を自己組織的に形成する工程と、前記ナノワイヤ中間体をアニール処理する工程とを経て作製したことを特徴とする、請求項１〜４のいずれか一に記載の酸素ガス検出素子。 The nanowire uses Cu + ions in an aqueous solution as a raw material, an acetylene gas is brought into contact with the raw material to form a crystalline nanowire intermediate in a self-organized manner, and a step of annealing the nanowire intermediate The oxygen gas detection element according to any one of claims 1 to 4, wherein the oxygen gas detection element is manufactured through the steps described above. 前記アセチレンガスは、前記原料に対して０．３ｍｌ／分以下の割合で接触させることを特徴とする、請求項５に記載の酸素ガス検出素子。   The oxygen gas detecting element according to claim 5, wherein the acetylene gas is brought into contact with the raw material at a rate of 0.3 ml / min or less. 前記アニール処理は、非酸化性雰囲気下、５０℃以上の温度で実施することを特徴とする、請求項５又は６に記載の酸素ガス検出素子。   The oxygen gas detection element according to claim 5 or 6, wherein the annealing treatment is performed at a temperature of 50 ° C or higher in a non-oxidizing atmosphere. Ｃｕコアと、このＣｕコアを被覆するようにして形成された炭素被覆層とを含むナノワイヤを具えることを特徴とする、酸素ガス検出素子用ナノワイヤ。   A nanowire for an oxygen gas detection element, comprising a nanowire including a Cu core and a carbon coating layer formed so as to cover the Cu core. 前記ナノワイヤの直径が５ｎｍ〜１０ｎｍであることを特徴とする、請求項８に記載の酸素ガス検出素子用ナノワイヤ。   The nanowire for an oxygen gas detection element according to claim 8, wherein the diameter of the nanowire is 5 nm to 10 nm. 前記ナノワイヤの長さが０．１μｍ〜１μｍであることを特徴とする、請求項８又は９に記載の酸素ガス検出素子用ナノワイヤ。   The nanowire for an oxygen gas detection element according to claim 8 or 9, wherein the nanowire has a length of 0.1 µm to 1 µm. 前記ナノワイヤは、水溶液中のＣｕ＋イオンを原料とし、この原料に対してアセチレンガスを接触させて結晶性のナノワイヤ中間体を自己組織的に形成する工程と、前記ナノワイヤ中間体をアニール処理する工程とを経て作製したことを特徴とする、請求項８〜１０のいずれか一に記載の酸素ガス検出素子用ナノワイヤ。 The nanowire uses Cu + ions in an aqueous solution as a raw material, an acetylene gas is brought into contact with the raw material to form a crystalline nanowire intermediate in a self-organized manner, and a step of annealing the nanowire intermediate The nanowire for oxygen gas detection elements according to any one of claims 8 to 10, which is manufactured through 前記アセチレンガスは、前記原料に対して０．３ｍｌ／分以下の割合で接触させることを特徴とする、請求項１１に記載の酸素ガス検出素子用ナノワイヤ。   The nanowire for an oxygen gas detection element according to claim 11, wherein the acetylene gas is brought into contact with the raw material at a rate of 0.3 ml / min or less. 前記アニール処理は、非酸化性雰囲気下、５０℃以上の温度で実施することを特徴とする、請求項１１又は１２に記載の酸素ガス検出素子用ナノワイヤ。   The nanowire for an oxygen gas detection element according to claim 11 or 12, wherein the annealing treatment is performed at a temperature of 50 ° C or higher in a non-oxidizing atmosphere.
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