• Title/Summary/Keyword: $C_2H_2$ sensor

Search Result 418, Processing Time 0.028 seconds

Fabrication of a Pd/poly 3C-SiC Schottky diode hydrogensensor and its characteristics (Pd/다결정 3C-SiC 쇼트키 다이오드형 수소센서의 제작과 그 특성)

  • Chung, Gwiy-Sang;Ahn, Jeong-Hak
    • Journal of Sensor Science and Technology
    • /
    • v.18 no.3
    • /
    • pp.222-225
    • /
    • 2009
  • This paper describes the fabrication and characteristics of Schottky micro hydrogen sensors for high temperatures by using polycrystalline(poly) 3C-SiC thin films grown on Si substrates with thermal oxide layer using APCVD. Pd/poly 3C-SiC Schottky diodes were made and evaluated by I-V and C-V measurements. Electric current density and barrier height voltage were $2{\times}10^{-3}A/cm^2$ and 0.58 eV, respectively. These devices could operate stably at about 400 $^{\circ}$. The characteristics of implemented sensors have been investigated in terms of sensitivity, linearity of response, response rate, and response time. Therefore, from these results, Pd/poly 3C-SiC Schottky devices have very high potential for high temperature $H_2$ sensor applications.

Polyester (PET) Fabric dyed with Lead (II) acetate-based Colorimetric Sensor for Detecting Hydrogen Sulfide (H2S) (황화수소(H2S) 감지를 위한 아세트산 납이 침염된 폴리에스터(PET) 섬유 기반의 변색성 센서)

  • Lee, Junyeop;Do, Nam Gon;Jeong, Dong Hyuk;Jung, Dong Geon;An, Hee Kyung;Kong, Seong Ho;Jung, Daewoong
    • Journal of Sensor Science and Technology
    • /
    • v.29 no.5
    • /
    • pp.360-364
    • /
    • 2020
  • In this study, the colorimetric sensor, polyester (PET) fabric dyed with lead (II) acetate (Pb(C2H3O2)2), was fabricated and characterized for the detection of the hydrogen sulfide (H2S). The surface morphology of the fabric was determined using scanning electron microscope and energy-dispersive X-ray spectroscopy. The optical properties of the fabric were evaluated by measuring the variation in the blue value of an RGB sensor. The fabric showed a significant color change, high linearity (R2 : 0.98256), and fast response time (< 1.0 s) when exposed to H2S. This is because the sensor is highly porous and permeable to the gas. The fabric can not only be used as a hydrogen sulfide sensor but also be used to detect and prevent H2S influx using sticky tape on pipelines.

Determination of Glutamine Utilizing New Plant Tissue Bio-Sensor (새로운 식물조직 바이오센서에 의한 글루타민의 정량)

  • Ihn, Gwon Shik;Kim, Bong Won;Jeon, Yeong Guk
    • Journal of the Korean Chemical Society
    • /
    • v.34 no.6
    • /
    • pp.622-628
    • /
    • 1990
  • The bio-sensor for glutamine has been constructed by immobilizing petal of the rose structural elements on an ammonia gas sensor. This sensor was investigated for the effects of pH, temperature, buffer solution, tissular amounts, interferences and lifetime. As a result, the tissue sensor showed linear range of $8.0 {\times} 10^{-4}$$5.0 {\times} 10^{-2}$ M glutamine with a slope of 52 mV/decade in pH 7.8, 0.2M phosphate beffer solution at 37$^{\circ}C$. The tissular amounts used for this sensor was 50 mg. This sensorr showed excellent selectivity. This sensor was compared with other structural elements of rose. Actually, this tissue sensor appeared to be very useful for the determination of glutamine.

  • PDF

H2S Micro Gas Sensor Based on a SnO2-CuO Multi-layer Thin Film

  • Kim, Sung-Eun;Choi, Woo-Chang
    • Transactions on Electrical and Electronic Materials
    • /
    • v.13 no.1
    • /
    • pp.27-30
    • /
    • 2012
  • This paper proposes a micro gas sensor for measuring $H_2S$ gas. This is based on a $SnO_2$-CuO multi-layer thin film. The sensor has a silicon diaphragm, micro heater, and sensing layers. The micro heater is embedded in the sensing layer in order to increase the temperature to an operating temperature. The $SnO_2$-CuO multi layer film is prepared by the alternating deposition method and thermal oxidation which uses an electron beam evaporator and a thermal furnace. To determine the effect of the number of layers, five sets of films are prepared, each with different number of layers. The sensitivities are measured by applying $H_2S$ gas. It has a concentration of 1 ppm at an operating temperature of $270^{\circ}C$. At the same total thickness, the sensitivity of the sensor with multi sensing layers was improved, compared to the sensor with one sensing layer. The sensitivity of the sensor with five layers to 1 ppm of $H_2S$ gas is approximately 68%. This is approximately 12% more than that of a sensor with one-layer.

Highly Sensitive and Selective Gas Sensors Using Catalyst-Loaded SnO2 Nanowires

  • Hwang, In-Sung;Lee, Jong-Heun
    • Journal of Sensor Science and Technology
    • /
    • v.21 no.3
    • /
    • pp.167-171
    • /
    • 2012
  • Ag- and Pd-loaded $SnO_2$ nanowire network sensors were prepared by the growth of $SnO_2$ nanowires via thermal evaporation, the coating of slurry containing $SnO_2$ nanowires, and dropping of a droplet containing Ag or Pd nanoparticles, and subsequent heat treatment. All the pristine, Pd-loaded and Ag-loaded $SnO_2$ nanowire networks showed the selective detection of $C_2H_5OH$ with low cross-responses to CO, $H_2$, $C_3H_8$, and $NH_3$. However, the relative gas responses and gas selectivity depended closely on the catalyst loading. The loading of Pd enhanced the responses($R_a/R_g$: $R_a$: resistance in air, $R_g$: resistance in gas) to CO and $H_2$ significantly, while it slightly deteriorated the response to $C_2H_5OH$. In contrast, a 3.1-fold enhancement was observed in the response to 100 ppm $C_2H_5OH$ by loading of Ag onto $SnO_2$ nanowire networks. The role of Ag catalysts in the highly sensitive and selective detection of $C_2H_5OH$ is discussed.

Gas Sensing Characteristics of Sb-doped SnO2 Nanofibers

  • Choi, Joong-Ki;Hwang, In-Sung;Kim, Sun-Jung;Park, Joon-Shik;Park, Soon-Sup;Dong, Ki-Young;Ju, Byeong-Kwon;Lee, Jong-Heun
    • Journal of Sensor Science and Technology
    • /
    • v.20 no.1
    • /
    • pp.1-7
    • /
    • 2011
  • Undoped and Sb-doped $SnO_2$ nanofibers were prepared by electrospinning and their responses to $H_2$, CO, $CH_4$, $C_3H_8$, and $C_2H_5OH$ were measured. In the undoped $SnO_2$ nanofibers, the gas response ($R_a/R_g$, $R_a$: resistance in air, $R_g$: resistance in gas) to 100 ppm $C_2H_5OH$ was very high(33.9), while that to the other gases ranged from 1.6 to 2.2. By doping with 2.65 wt% Sb, the response to 100 ppm $C_2H_5OH$ was decreased to 4.5, whereas the response to $H_2$ was increased to 3.0. This demonstrates the possibility of detecting a high $H_2$ concentration with minimum interference from $C_2H_5OH$ and the potential to control the gas selectivity by Sb doping.

Semiconductor type micro gas sensor for $H_2$ detection using a $SnO_2-Ag_2O-PtO_x$ system by screen printing technique (스크린 프린팅 기법을 이용한 $SnO_2-Ag_2O-PtO_x$계 반도체식 마이크로 수소 가스센서에 관한 연구)

  • Kim, Il-Jin;Han, Sang-Do;Lee, Hi-Deok;Wang, Jin-Suk
    • Transactions of the Korean hydrogen and new energy society
    • /
    • v.17 no.1
    • /
    • pp.69-74
    • /
    • 2006
  • Thick film $H_2$ sensors were fabricated using $SnO_2$ loaded with $Ag_2O$ and $PtO_x$. The composition that gave the highest sensitivity for $H_2$ was in the weight% ratio of $SnO_2 : PtO_x : Ag_2O$ as 93 : 1 : 6. The nano-crystalline powders of $SnO_2$ synthesized by sol-gel method were screen printed with $Ag_2O$ and $PtO_x$ on alumina substrates. The fabricated sensors were tested against gases like $H_2$, $CH_4$, $C_3H_8$, $C_2H_5OH$ and $SO_2$. The composite material was found sensitive against $H_2$ at the working temperature $130^{\circ}C$, with minor interference of other gases. The $H_2$ gas as low as 100 ppm can be detected by the present fabricated sensors. It was found that the sensors based on $SnO_2-Ag_2O-PtO_x$ system exhibited the high performance, high selectivity and very short response time to $H_2$ at ppm level. These characteristics make the sensor to be a promising candidate for detecting low concentrations of $H_2$.

Gas Sensing Characteristics of Catalyst-added $In_2O_3$ Thick Film for Detecting $NO_x$ of High Concentration (고농도 $NO_x$ 감지용 $In_2O_3$ 후막가스센서의 Al, Ru 및 $SnO_2$ 첨가에 의한 특성 향상)

  • 박종현;김동현;이종영;김광호
    • Journal of the Korean Ceramic Society
    • /
    • v.36 no.12
    • /
    • pp.1322-1326
    • /
    • 1999
  • In2O3 thick film gas sensor for detecting NOx gas of high concentration was fabricated by a screen printing technique. This work focussed on investigation of the change of sensitivity to NOx gas with firing temperatures of sensing layer and on improvement of the sensitivity by adding catalysts such as Al,. Ru, and SnO2 The cross sensitivites of sensor to CO, H2, CH4 and i-C4H10 gases were also examined under NO2 gas concentration of 200ppm Pure In2O3 gas sensor prepared at a firing temperature of 50$0^{\circ}C$ showed a maximum sensitivity to NOx gas at the operating temperature of 40$0^{\circ}C$ Al(0.004 wt%)-In2O3 sensor largely improved the sensitivities to both NO2 and NO gas and showed a superior selectivity compared with other gas sensors.

  • PDF

Highly Sensitive and Selective Ethanol Sensors Using Magnesium doped Indium Oxide Hollow Spheres

  • Jo, Young-Moo;Lee, Chul-Soon;Wang, Rui;Park, Joon-Shik;Lee, Jong-Heun
    • Journal of the Korean Ceramic Society
    • /
    • v.54 no.4
    • /
    • pp.303-307
    • /
    • 2017
  • Pure $In_2O_3$, 0.5 and 1.0 wt% Mg doped $In_2O_3$ hollow spheres were synthesized by ultrasonic spray pyrolysis of a solution containing In-, Mg-nitrate and sucrose and their gas sensing characteristics to 5 ppm $C_2H_5OH$, p-xylene, toluene, and HCHO were measured at 250, 300 and $350^{\circ}C$. Although the addition of Mg decreases the specific surface area and the volume of meso-pores, the gas response (resistance ratio) of the 0.5 wt% Mg doped $In_2O_3$ hollow spheres to 5 ppm $C_2H_5OH$ at $350^{\circ}C$ (69.4) was significantly higher than that of the pure $In_2O_3$ hollow spheres (24.4). In addition, the Mg doped $In_2O_3$ hollow spheres showed the highest selectivity to $C_2H_5OH$. This was attributed to the dehydrogenation of $C_2H_5OH$ assisted by basic MgO into reactive $CH_3CHO$ and $H_2$.

Development of High Sensitive Integrated Dual Sensor to Detect Harmful Exhaust Gas and Odor for the Automotive (악취분별능력을 가진 자동차용 고기능 듀얼타입 집적형 유해가스 유입차단센서 개발)

  • Chung, Wan-Young;Shim, Chang-Hyun
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.13 no.7
    • /
    • pp.616-623
    • /
    • 2007
  • A dual micro gas sensor array was fabricated using nano sized $SnO_2$ thin films which had good sensitivities to CO and combustible gases, or $H_2S$ gas for air quality sensors in automobile. The already existed air quality sensor detects oxidizing gases and reducing gases, the air quality sensor(AQS), located near the fresh air inlet detected the harmful gases, the fresh air inlet door/ventilation flap was closed to reduce the amount of pollution entering the vehicle cabin through HVAC(heating, ventilating, and air conditioning) system. In this study, to make $SnO_2$ thin film AQS sensor, thin tin metal layer between 1000 and $2000{\AA}$ thick was oxidized between 600 and $800^{\circ}C$ by thermal oxidation. The gas sensing layers such as $SnO_2$, $SnO_2$(pt) and $SnO_2$(+CuO) were patterned by metal shadow mask for simple fabrication process on the silicon substrate. The micro gas sensors with $SnO_2$(+Pt) and $SnO_2$(CuO) showed good selectivity to CO gas among reducing gases and good sensitivity to $H_2S$ that is main component of bad odor, separately.