WO2012081961A1 - Chemical resistive gas sensor for hydrogen sulphide - Google Patents

Chemical resistive gas sensor for hydrogen sulphide Download PDF

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Publication number
WO2012081961A1
WO2012081961A1 PCT/MY2011/000101 MY2011000101W WO2012081961A1 WO 2012081961 A1 WO2012081961 A1 WO 2012081961A1 MY 2011000101 W MY2011000101 W MY 2011000101W WO 2012081961 A1 WO2012081961 A1 WO 2012081961A1
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Prior art keywords
carbon nanotubes
gold
boron doped
hydrogen sulphide
substrate
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PCT/MY2011/000101
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French (fr)
Inventor
Aarti Srirangarajan
Lim Hoe Tian
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Mimos Bhd
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Mimos Bhd
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • 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
    • G01N27/125—Composition of the body, e.g. the composition of its sensitive layer
    • G01N27/127—Composition of the body, e.g. the composition of its sensitive layer comprising nanoparticles
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
    • G01N33/0004—Gaseous mixtures, e.g. polluted air
    • G01N33/0009—General constructional details of gas analysers, e.g. portable test equipment
    • G01N33/0027—General constructional details of gas analysers, e.g. portable test equipment concerning the detector
    • G01N33/0036—General constructional details of gas analysers, e.g. portable test equipment concerning the detector specially adapted to detect a particular component
    • G01N33/0044—Sulphides, e.g. H2S

Definitions

  • the present invention relates to chemical resistive gas sensor, more particularly to boron-doped gold functionalized metallic carbon nanotube structure for hydrogen sulphide gas sensor device.
  • Sub ppm level sensors for hydrogen sulphide gas are in high demand because of the toxic nature of hydrogen sulphide gas, where even trace amount of it in the environment can cause harmful effects.
  • the sensor is useful in environmental monitoring, petroleum industry and food monitoring industry.
  • the present invention proposes an incorporated boron-doped gold functionalized metallic carbon nanotube structure for hydrogen sulphide gas sensor device.
  • the use of metallic or semiconducting carbon nanotubes in place of purely semiconducting carbon nanotubes eliminates the effect of parasitic charges on the substrate and enhances the selectivity towards hydrogen sulphide gas in trace amount.
  • the enhancement is via the use of gold functionalisation. Adhesion improvement of gold nanoparticles to the carbon nanotubes are achieved by using boron doped carbon nanotubes.
  • a chemical resistive gas sensor for hydrogen sulphide comprising: a substrate [26]; an insulating layer [24] on the substrate [26]; interdigitated electrodes [22] on insulating layer [24]; characterized in that, gold functionalised boron doped carbon nanotubes [20] drop deposited onto the gaps between the interdigitated electrode area, wherein the gold functionalised boron doped carbon nanotubes [20] enhances the selectivity and sensitivity of the sensor towards hydrogen sulphide gas.
  • the substrate [26] is silicon and the insulating layer [24] is silicon oxide.
  • a method of fabricating chemical resistive gas sensor device comprising: growing boron doped carbon nanotubes [20] via chemical vapour deposition; fabricating interdigitated electrodes [22] by photolitgraphy and evaporation of gold on an insulating layer [24] with substrate [26]; purifying grown boron doped carbon nanotubes [20]; dispersing pure grown boron doped carbon nanotubes [20] in dimethylformamide (DMF); drop- depositing solution of pure grown boron doped carbon nanotubes [20] in DMF onto the gaps between the electrode areas; forming a network of carbon nanotubes [20] over the interdigitated electrode [22] area after evaporation of DMF; functionalizing carbon nanotubes [20] with gold using electrodeposition technique; and aligning drop casted carbon nanotubes [20] using dielectrophoresis.
  • DMF dimethylformamide
  • Fig. 1 is a schematic drawing of one of the embodiments of the incorporated boron- doped gold functionalized metallic carbon nanotube sensor structure.
  • Fig. 2 is a flowchart of the incorporated boron-doped gold functionalized metallic carbon nanotube sensor fabrication process. DESCRIPTION OF EMBODIMENTS
  • the invention involves an incorporated boron-doped gold functionalized metallic carbon nanotube structure for hydrogen sulphide gas sensor device.
  • the chemical resistive gas sensor device consist of gold functionalised boron doped carbon nanotube [20], interdigitated gold electrodes [22] deposited via photolithography on top of an insulating layer [24] which is deposited earlier on a substrate [26].
  • An embodiment of the insulating layer and substrate is silicon oxide and silicon.
  • FIG. 1 The schematic drawing of the structure is shown in Fig. 1.
  • the first step is to grow boron doped carbon nanotubes [20] via chemical vapour deposition where methanol solution of boric acid is flowed into an electric furnace onto a substrate pre-coated with catalyst.
  • a layer of silicon oxide [24] is deposited onto a silicon substrate [26]. This silicon substrate [26] and silicon oxide [24] acts as insulating layer. This is followed by fabrication of interdigitated electrodes [22] by photolitgraphy and evaporation of gold on the silicon dioxide [24] layer.
  • the grown boron doped carbon nanotubes [20] are then purified and then dispersed in dimethylformamide (DMF). This solution is then drop deposited onto the gaps between the electrode areas. A network of carbon nanotubes [20] is formed over the interdigitated electrode [22] area after the evaporation of DMF.
  • the carbon nanotubes [20] are then functionalized with gold using electrodeposition technique where gold functionalisation takes place selectively at the boron doped site. Then, the drop casted carbon nanotubes [20] are aligned using dielectrophoresis followed by encapsulation of the sensor.
  • Hydrogen sulphide is detected using the sensor when gas molecules [28] of hydrogen sulphide are absorbed on the gold functionalised boron doped carbon nanotubes [20] surface and causes a change in the resistivity of the sensor, allowing detection.
  • the invention disclosed the fabrication of incorporated boron-doped gold functionalized metallic carbon nanotube [20] structure for hydrogen sulphide gas sensor device.
  • This type of chemical resistive sensor can detect hydrogen sulphide gas molecules [28] at the sub ppm level.
  • the unique feature of the sensor is the gold functionalised boron doped carbon nanotubes [20] structure which is used to enhance the selectivity and sensitivity towards hydrogen sulphide gas. Besides that, the boron doping also helps in improving the adhesion of gold nanoparticles to the carbon nanotube [20].

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Nanotechnology (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • Food Science & Technology (AREA)
  • Medicinal Chemistry (AREA)
  • Combustion & Propulsion (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Composite Materials (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Materials Engineering (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Investigating Or Analyzing Materials By The Use Of Fluid Adsorption Or Reactions (AREA)

Abstract

The present invention provides an incorporated boron-doped gold functionalized metallic carbon nanotube [20] structure for hydrogen sulphide gas sensor device. This type of chemical resistive sensor can detect hydrogen sulphide gas molecules [28] at the sub ppm level. The unique feature of the sensor is the gold functionalised boron doped carbon nanotubes [20] structure which is used to enhance the selectivity and sensitivity towards hydrogen sulphide gas. When hydrogen sulphide gas molecules [28] are absorbed on the gold functionalised boron doped carbon nanotubes [20] surface a change in the resistivity of the sensor is caused, therefore allowing detection.

Description

CHEMICAL RESISTIVE GAS SENSOR FOR HYDROGEN SULPHIDE
The present invention relates to chemical resistive gas sensor, more particularly to boron-doped gold functionalized metallic carbon nanotube structure for hydrogen sulphide gas sensor device.
BACKGROUND ART
Sub ppm level sensors for hydrogen sulphide gas are in high demand because of the toxic nature of hydrogen sulphide gas, where even trace amount of it in the environment can cause harmful effects. The sensor is useful in environmental monitoring, petroleum industry and food monitoring industry.
Most sensors today use semiconducting carbon nanotubes for their analyte dependent conduction modulation which is the ChemFET sensor type.
A prior art listed the invention of nano-material based gas sensor in which gas sensing is made using semi-conducting nano-material and similar gating mechanism. Another prior art listed the detection of hydrogen sulphide using gold nanoparticle decorated single- walled carbon nanotubes. This sensor uses the analyte-dependent gating mechanism where carboxylated carbon nanotubes are used to create defects in carbon nanotube structure followed by electrodeposition of gold NPs on the defective carbon nanotubes.
The above prior arts displayed the disadvantages of having drawbacks in the semiconducting devices where parasitic charges present in the substrate can affect the sensor stability and selectivity. Also the growth process of the carbon nanotube produces both metallic and semiconducting carbon nanotubes and their separation is still a challenge. Certain gases such as Hydrogen Sulphide, have low affinity towards pure carbon Nanotubes while gold nanoparticles have poor adhesion on to pure carbon nanotubes surface. The present invention is made in view of the need to eliminate the drawbacks of using FET based sensor mechanism which led to parasitic charges while enhancing the selectivity towards hydrogen sulphide gas in trace amounts. SUMMARY OF INVENTION
The present invention proposes an incorporated boron-doped gold functionalized metallic carbon nanotube structure for hydrogen sulphide gas sensor device. The use of metallic or semiconducting carbon nanotubes in place of purely semiconducting carbon nanotubes eliminates the effect of parasitic charges on the substrate and enhances the selectivity towards hydrogen sulphide gas in trace amount. The enhancement is via the use of gold functionalisation. Adhesion improvement of gold nanoparticles to the carbon nanotubes are achieved by using boron doped carbon nanotubes.
A chemical resistive gas sensor for hydrogen sulphide, comprising: a substrate [26]; an insulating layer [24] on the substrate [26]; interdigitated electrodes [22] on insulating layer [24]; characterized in that, gold functionalised boron doped carbon nanotubes [20] drop deposited onto the gaps between the interdigitated electrode area, wherein the gold functionalised boron doped carbon nanotubes [20] enhances the selectivity and sensitivity of the sensor towards hydrogen sulphide gas. The substrate [26] is silicon and the insulating layer [24] is silicon oxide.
A method of fabricating chemical resistive gas sensor device, comprising: growing boron doped carbon nanotubes [20] via chemical vapour deposition; fabricating interdigitated electrodes [22] by photolitgraphy and evaporation of gold on an insulating layer [24] with substrate [26]; purifying grown boron doped carbon nanotubes [20]; dispersing pure grown boron doped carbon nanotubes [20] in dimethylformamide (DMF); drop- depositing solution of pure grown boron doped carbon nanotubes [20] in DMF onto the gaps between the electrode areas; forming a network of carbon nanotubes [20] over the interdigitated electrode [22] area after evaporation of DMF; functionalizing carbon nanotubes [20] with gold using electrodeposition technique; and aligning drop casted carbon nanotubes [20] using dielectrophoresis. BRIEF DESCRIPTION OF DRAWINGS
Fig. 1 is a schematic drawing of one of the embodiments of the incorporated boron- doped gold functionalized metallic carbon nanotube sensor structure.
Fig. 2 is a flowchart of the incorporated boron-doped gold functionalized metallic carbon nanotube sensor fabrication process. DESCRIPTION OF EMBODIMENTS
Hereinafter, the present invention is described in detail. The invention involves an incorporated boron-doped gold functionalized metallic carbon nanotube structure for hydrogen sulphide gas sensor device. The chemical resistive gas sensor device consist of gold functionalised boron doped carbon nanotube [20], interdigitated gold electrodes [22] deposited via photolithography on top of an insulating layer [24] which is deposited earlier on a substrate [26]. An embodiment of the insulating layer and substrate is silicon oxide and silicon.
The schematic drawing of the structure is shown in Fig. 1.
To fabricate the sensor, the first step is to grow boron doped carbon nanotubes [20] via chemical vapour deposition where methanol solution of boric acid is flowed into an electric furnace onto a substrate pre-coated with catalyst. On the other hand, a layer of silicon oxide [24] is deposited onto a silicon substrate [26]. This silicon substrate [26] and silicon oxide [24] acts as insulating layer. This is followed by fabrication of interdigitated electrodes [22] by photolitgraphy and evaporation of gold on the silicon dioxide [24] layer.
The grown boron doped carbon nanotubes [20] are then purified and then dispersed in dimethylformamide (DMF). This solution is then drop deposited onto the gaps between the electrode areas. A network of carbon nanotubes [20] is formed over the interdigitated electrode [22] area after the evaporation of DMF. The carbon nanotubes [20] are then functionalized with gold using electrodeposition technique where gold functionalisation takes place selectively at the boron doped site. Then, the drop casted carbon nanotubes [20] are aligned using dielectrophoresis followed by encapsulation of the sensor.
The fabrication process of the sensor is shown in flowchart, Fig. 2.
Hydrogen sulphide is detected using the sensor when gas molecules [28] of hydrogen sulphide are absorbed on the gold functionalised boron doped carbon nanotubes [20] surface and causes a change in the resistivity of the sensor, allowing detection. Accordingly, the invention disclosed the fabrication of incorporated boron-doped gold functionalized metallic carbon nanotube [20] structure for hydrogen sulphide gas sensor device. This type of chemical resistive sensor can detect hydrogen sulphide gas molecules [28] at the sub ppm level. The unique feature of the sensor is the gold functionalised boron doped carbon nanotubes [20] structure which is used to enhance the selectivity and sensitivity towards hydrogen sulphide gas. Besides that, the boron doping also helps in improving the adhesion of gold nanoparticles to the carbon nanotube [20].

Claims

A chemical resistive gas sensor for hydrogen sulphide, comprising:
a substrate [26];
an insulating layer [24] on the substrate [26];
interdigitated electrodes or any other electrodes [22] on insulating layer [24];
characterized in that,
gold functionalised boron doped carbon nanotubes [20] drop deposited onto the gaps between the interdigitated electrode or any other type of electrodes area,
wherein the gold functionalised boron doped carbon nanotubes [20] enhances the selectivity and sensitivity of the sensor towards hydrogen sulphide gas.
A sensor according to claim 1 , wherein the substrate [26] is silicon and the insulating layer [24] is silicon oxide but can be any other substrate and insulating layer.
A sensor according to claim 1 , wherein the interdigitated electrodes [22] is preferably gold but can be any conducting material.
A method of fabricating chemical resistive gas sensor device, comprising:
growing boron doped carbon nanotubes [20] via chemical vapour deposition; fabricating interdigitated electrodes [22] by photolitgraphy and evaporation of gold on an insulating layer [24] with substrate [26];
purifying grown boron doped carbon nanotubes [20];
dispersing pure grown boron doped carbon nanotubes [20] in dimethylformamide (DMF);
drop-depositing solution of pure grown boron doped carbon nanotubes [20] in DMF onto the gaps between the electrode areas;
forming a network of carbon nanotubes [20] over the interdigitated electrode [22] area after evaporation of DMF;
functionalizing carbon nanotubes [20] with gold using electrodeposition technique; aligning drop casted carbon nanotubes [20] using dielectrophoresis.
5. A method according to claim 4, wherein the growing of boron doped carbon nanotube
[20] via chemical vapour deposition is achieved by flowing methanol solution of boric acid onto a substrate pre-coated with catalyst in an electric furnace.
6. A method according to claim 4, wherein the electrodeposition technique to functionalize carbon nanotubes [20] with gold is a technique where gold functionalisation will take place selectively at boron doped site only.
PCT/MY2011/000101 2010-12-14 2011-06-17 Chemical resistive gas sensor for hydrogen sulphide Ceased WO2012081961A1 (en)

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MYPI2010700096A MY157261A (en) 2010-12-14 2010-12-14 Chemical resistive gas sensor for hydrogen sulphide

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
RU2609793C1 (en) * 2015-11-17 2017-02-03 Федеральное государственное автономное образовательное учреждение высшего образования "Национальный исследовательский университет "Московский институт электронной техники" (МИЭТ) Resistive sensor with transparent conductive electrode
CN109211459A (en) * 2018-07-26 2019-01-15 西北工业大学 A kind of flexible carbon nano tube thermosensitive film shear stress microsensor and its manufacturing method
CN116448840A (en) * 2023-05-21 2023-07-18 湘潭大学 Sensor based on carbon nano tube interdigital electrode structure and preparation method thereof

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EP1790977A1 (en) * 2005-11-23 2007-05-30 SONY DEUTSCHLAND GmbH Nanoparticle/nanofiber based chemical sensor, arrays of such sensors, uses and method of fabrication thereof, and method of detecting an analyte
WO2008140649A2 (en) * 2007-03-07 2008-11-20 Carbolex, Inc. Boron-doped single-walled nanotubes (swcnt)
WO2008153593A1 (en) * 2006-11-10 2008-12-18 Bourns Inc. Nanomaterial-based gas sensors
US7801687B1 (en) * 2005-07-08 2010-09-21 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration (Nasa) Chemical sensors using coated or doped carbon nanotube networks

Patent Citations (4)

* Cited by examiner, † Cited by third party
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US7801687B1 (en) * 2005-07-08 2010-09-21 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration (Nasa) Chemical sensors using coated or doped carbon nanotube networks
EP1790977A1 (en) * 2005-11-23 2007-05-30 SONY DEUTSCHLAND GmbH Nanoparticle/nanofiber based chemical sensor, arrays of such sensors, uses and method of fabrication thereof, and method of detecting an analyte
WO2008153593A1 (en) * 2006-11-10 2008-12-18 Bourns Inc. Nanomaterial-based gas sensors
WO2008140649A2 (en) * 2007-03-07 2008-11-20 Carbolex, Inc. Boron-doped single-walled nanotubes (swcnt)

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ISHII ET AL.: "High-conductivity boron-doped carbon nanotubes", SPIE NEWSROOM, 31 July 2007 (2007-07-31), pages 1 - 2 *
MUBEEN ET AL.: "Sensitive Detection of H2S using Gold Nanoparticle Decorated Single-Walled Carbon Nanotubes", ANALYTICAL CHEMISTRY, vol. 82, no. 1, January 2010 (2010-01-01), pages 250 - 257, XP055184654, DOI: doi:10.1021/ac901871d *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
RU2609793C1 (en) * 2015-11-17 2017-02-03 Федеральное государственное автономное образовательное учреждение высшего образования "Национальный исследовательский университет "Московский институт электронной техники" (МИЭТ) Resistive sensor with transparent conductive electrode
CN109211459A (en) * 2018-07-26 2019-01-15 西北工业大学 A kind of flexible carbon nano tube thermosensitive film shear stress microsensor and its manufacturing method
CN116448840A (en) * 2023-05-21 2023-07-18 湘潭大学 Sensor based on carbon nano tube interdigital electrode structure and preparation method thereof

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