Michelson Interferometric Hydrogen Sulfide Gas Sensor Based on NH2-rGO Sensitive Film

2020 ◽  
Vol 75 (3) ◽  
pp. 241-248 ◽  
Author(s):  
Shaodian Liu ◽  
Xiaozhan Yang ◽  
Wenlin Feng ◽  
Hongliang Chen ◽  
Yu Tao ◽  
...  
Keyword(s):  
Hydrogen Sulfide ◽  
Gas Sensor ◽  
Michelson Interferometer ◽  
High Sensitivity ◽  
Single Mode ◽  
Blue Shift ◽  
Light Signal ◽  
Sensitive Film ◽  
Recovery Times ◽  
Response And Recovery

AbstractA highly sensitive hydrogen sulfide gas sensor based on NH2-rGO-coated thin-core-fibre (TCF) Michelson interferometer (MI) is proposed and evaluated. Two sections of TCFs are alternately sandwiched between three single-mode-fibres (SMFs). A Faraday rotator mirror (FRM) is fixed to the end of the last SMF to reflect the light signal and enhance the interference. Then the structure SMF-TCF-SMF-TCF-SMF-FRM (STSTS-F) is successfully constructed. NH2-rGO, as sensing film, is coated on two TCFs and is used to detect traces of hydrogen sulfide gas. Raman spectra and XPS analysis show that NH2-rGO has been successfully synthesised. The thickness of the NH2-rGO film coated on the TCF surface is about 500 nm. By introducing 0–60 ppm hydrogen sulfide gas into the chamber, with the increase in concentration of the gas, the monitoring trough exhibits a blue shift. Our experimental results show that the sensor has good linearity (R2 = 0.98096) and selectivity for hydrogen sulfide gas. The sensitivity is 21.3 pm/ppm, and the response and recovery times are about 72 and 90 s, respectively. The sensor has the advantages of high sensitivity, high selectivity, and small size, enabling the detection of trace hydrogen sulfide in toxic gas environments.

Hydrogen Sulfide Gas Sensor Based on Copper/Graphene Oxide Composite Film-Coated Tapered Single-Mode Fibre Interferometer

2019 ◽  
Vol 74 (10) ◽  
pp. 931-936 ◽  
Author(s):  
Jiahao Yu ◽  
Xiaozhan Yang ◽  
Wenlin Feng
Keyword(s):  
Graphene Oxide ◽  
Hydrogen Sulfide ◽  
Gas Sensor ◽  
Limit Of Detection ◽  
Low Cost ◽  
Single Mode ◽  
Wavelength Shift ◽  
Sensitive Film ◽  
On Line ◽  
Cladding Mode

AbstractA hydrogen sulfide (H2S) gas sensor based on copper (Cu) nanoparticle deposited graphene oxide (GO) composite membrane with two waist-enlarged tapers is proposed. Three segments of the single-mode fibres (SMFs) are sequentially fused to obtain two waist-enlarged bitapers of Mach–Zehnder interferometer (MZI). When the light of a broadband light source transmits through the first bitaper, some light enters the fiber cladding; the lights of core mode and cladding mode are coupled at the second taper and an MZI is successfully fabricated. The copper/graphene oxide (Cu/GO) composite sensing film is coated on the surface of the second SMF, and the effective refractive index of the coating is changed when the sensitive film adsorbs the target gas. The correlation between the gas concentration and the wavelength shift is achieved and the H2S can be measured effectively. The results show that a uniform Cu/GO film is successfully coated on the surface of the fiber, and when the thickness of the sensitive film is about 1.2 μm, the sensor has a sensitivity of 4.42 pm/ppm and a good linearity and selectivity for H2S in the range of 0–60 ppm, and the limit of detection is 2.79 ppm. The response time and recovery time are approximately 31 and 48 s, respectively. The sensor has the advantages of small volume, low cost, simple structure, and easy manufacture and so on, which is suitable for on-line monitoring of H2S.

scholarly journals Tin Disulfide-Coated Microfiber for Humidity Sensing with Fast Response and High Sensitivity

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 648
Author(s):  
Aijie Liang ◽  
Jingyuan Ming ◽  
Wenguo Zhu ◽  
Heyuan Guan ◽  
Xinyang Han ◽  
...  
Keyword(s):  
Humidity Sensor ◽  
Small Diameter ◽  
High Sensitivity ◽  
Large Change ◽  
Small Variation ◽  
Response Speed ◽  
Fast Response ◽  
Tin Disulfide ◽  
Recovery Times ◽  
Response And Recovery

Breath monitoring is significant in assessing human body conditions, such as cardiac and pulmonary symptoms. Optical fiber-based sensors have attracted much attention since they are immune to electromagnetic radiation, thus are safe for patients. Here, a microfiber (MF) humidity sensor is fabricated by coating tin disulfide (SnS2) nanosheets onto the surface of MF. The small diameter (~8 μm) and the long length (~5 mm) of the MF promise strong interaction between guiding light and SnS2. Thus, a small variation in the relative humidity (RH) will lead to a large change in optical transmitted power. A high RH sensitivity of 0.57 dB/%RH is therefore achieved. The response and recovery times are estimated to be 0.08 and 0.28 s, respectively. The high sensitivity and fast response speed enable our SnS2-MF sensor to monitor human breath in real time.

Using Palladium Nanocubes on ZnO Nanostructures in Hydrogen Gas Sensor for Fast Response and Recovery Time

2021 ◽  
Vol 21 (4) ◽  
pp. 2495-2499
Author(s):  
Hoang Si Hong ◽  
Tran Vinh Hoang
Keyword(s):  
Gas Sensor ◽  
Recovery Time ◽  
Fast Response ◽  
Hydrogen Gas ◽  
Zno Nanostructures ◽  
Response Recovery ◽  
Sensor Structure ◽  
Recovery Times ◽  
Response And Recovery ◽  
Robust Sensing

We developed a novel sensor structure by synthesizing Pd nanocubes (NCs) decorated on ZnO nanostructures (NSs) applied to resistive-type H2 gas sensor with micro-length in sensing channel. The ZnO NSs were selectively grown between micro-size finger-like interdigital electrodes through microelectromechanical technology. The novel H2 sensor structure with the sensing channel was reduced to micro-size by this proposed method to obtain a sensor with fast response/recovery time. The as-prepared structure exhibited robust sensing performance with a response of 11% at optimal temperature of 150 °C, good linearity, and fast response/recovery time within 10 s. The speed of chemisorption through the diffusion pathway in Pd NCs combined with micro-length in sensing channel in sensor showed fast response and recovery times of 9 and 15 s, respectively, toward 10,000 ppm (1%) H2 at 150 °C. The result showed approximate linearity response in H2 concentration range of 5÷10,000 ppm and a large operating temperature range from room temperature to 200 °C.

Dual MOSFET Hydrogen Sensors with Thermal Island Structure

2013 ◽  
Vol 543 ◽  
pp. 93-96
Author(s):  
Bum Joon Kim ◽  
Jung Sik Kim
Keyword(s):  
Gas Sensor ◽  
Hydrogen Sensor ◽  
Hydrogen Gas ◽  
Hydrogen Sensors ◽  
Optimal Point ◽  
Reference Device ◽  
Recovery Times ◽  
Dual Gate ◽  
Response And Recovery ◽  
Effect Transistor

A low powered hydrogen gas sensor of the FET (field-effect transistor) structure was designed, fabricated and characterized for self-compensation to outer environments. The dual-gate FET hydrogen sensor was integrated with a micro-heater and two Pt-gate FETs; a sensing device for hydrogen detection, and a reference device as an electrical compensator. The identical output between the sensitive-FET and reference-FET was stable at temperatures ranging from room temperature to 250°C due to the same temperature dependence of the currentvoltage (IV) characteristics. The Pt-FET sensor showed stable responses to hydrogen at a range of operation temperatures. The optimal point in the micro-heater operation for 5,000 ppm H2 gas injection was approximately 150°C. The highest sensitivity was 0.112 mA, and the response and recovery times were 18 sec and 19 sec, respectively. The low-power MOSFET gas sensor was found to be suitable for applications in portable gas monitoring units and automobiles.

High Response and Selectivity Methanol Gas Sensor Using Molecular Imprinting Technique

2014 ◽  
Vol 809-810 ◽  
pp. 731-736
Author(s):  
Qin Zhu ◽  
Yu Min Zhang ◽  
Jin Zhang ◽  
Zhong Qi Zhu ◽  
Qing Ju Liu
Keyword(s):  
Gas Sensor ◽  
Gas Sensing ◽  
High Response ◽  
Molar Ratio ◽  
Methanol Vapor ◽  
Sensing Properties ◽  
Gas Sensing Properties ◽  
Recovery Times ◽  
Response And Recovery ◽  
Infrared Spectrometer

A new gas sensor with high response and selectivity was fabricated by using molecularly imprinted powders (MIPs) which provide special recognition sites to methanol. The MIPs were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and fourier transform infrared spectrometer (FT-IR), respectively. The gas sensing properties of MIPs to methanol were investigated. The experimental results indicate that the sensors based on the MIPs show excellent gas sensing properties to methanol vapor, and the properties of the sensor with x=6:10 (x= methyl acrylic acid: LaFeO3, molar ratio) are the best. At the optimal operating temperature of 130°C, the response of the sensor (x=6:10) to 1 ppm methanol is 21, and the response and recovery times are 57 s and 67 s, respectively.

Carbon monoxide gas sensor based on α-Fe2O3/rGOQDs composite film integrated Michelson interferometer

2021 ◽  
Author(s):  
Sijie He ◽  
Yushan Liu ◽  
Wenlin Feng ◽  
Bangxin Li ◽  
Xiao-Zhan Yang ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Composite Film ◽  
Silver Film ◽  
Simple Structure ◽  
High Selectivity ◽  
Michelson Interferometer ◽  
High Sensitivity ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Core Fiber

Abstract A carbon monoxide sensor based on Michelson interferometer combined with α-Fe2O3/rGOQDs composite film is proposed and fabricated. First, a waist-enlarged taper is formed between the single-mode fiber (SMF) and the no-core fiber (NCF), then the other end of the NCF is spliced with a section of thin-core fiber (TCF). Besides, the end of the TCF is coated with a layer of silver film to enhance the reflection. Thus, the Michelson interferometer of SMF-NCF-TCF is formed. The α-Fe2O3/rGOQDs composite film is deposited on the outside surface of TCF. The specific adsorption of carbon monoxide by the composite film leads to the change of the sensor’s effective refractive index (RI), realizing the detection of carbon monoxide. The results show that the interference intensity of the monitoring valley decreases with the increase of the concentration of carbon monoxide. The sensitivity of the sensor is 0.057 dBm/ppm, the detection limit of the sensor is 105 ppb, and the response time and recovery time are 70 s and 100 s, respectively. The sensor has the advantages of high sensitivity, high selectivity and simple structure, and it is expected to be applied for the detection of carbon monoxide gas with low concentration.

High sensitivity and fast response and recovery times in a ZnO nanorod array/p-Si self-powered ultraviolet detector

2012 ◽  
Vol 101 (26) ◽  
pp. 261108 ◽  
Author(s):  
J. J. Hassan ◽  
M. A. Mahdi ◽  
S. J. Kasim ◽  
Naser M. Ahmed ◽  
H. Abu Hassan ◽  
...  
Keyword(s):  
High Sensitivity ◽  
Nanorod Array ◽  
Fast Response ◽  
Zno Nanorod ◽  
Ultraviolet Detector ◽  
Recovery Times ◽  
Response And Recovery ◽  
Zno Nanorod Array ◽  
Self Powered

A Flexible Humidity Sensor Based on Co3O4 Nanoneedles with High Sensitivity and Quick Response

2020 ◽  
Vol 15 (7) ◽  
pp. 870-874
Author(s):  
Qi Qi ◽  
Qi Wang ◽  
Nanliu Liu ◽  
Xiaoping Zheng ◽  
Xiongjie Ding ◽  
...  
Keyword(s):  
Humidity Sensor ◽  
High Sensitivity ◽  
Current Sensor ◽  
Quick Response ◽  
Bending Tests ◽  
Humidity Sensing ◽  
Recovery Times ◽  
Response And Recovery ◽  
Sensing Performance ◽  
Semilogarithmic Scale

A flexible humidity sensor has been realized based on Co3O4 nanoneedles via a deposition technique. High humidity sensing and excellent flexible properties are observed in the tests. The impedance of the as-prepared sensor decreases by nearly three orders of magnitude with increasing relative humidity (RH) from 11% to 95% on a semilogarithmic scale. The response and recovery times are about 3 and 6 s respectively. The maximum hysteresis is less than 4% under 80% RH. No obvious changes for the sensing performance can be obtained after 100 bending/extending cycles and bending tests. These performances make the current sensor a good candidate for flexible humidity detection.

scholarly journals Study of Two Vanadium Based Materials as Working Electrode for Developing A Selective Mixed-Potential Ammonia Sensor

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 770
Author(s):  
Gita Nematbakhsh Abkenar ◽  
Jean-Paul Viricelle ◽  
Mathilde Rieu ◽  
Philippe Breuil
Keyword(s):  
Reference Electrode ◽  
High Sensitivity ◽  
Fast Response ◽  
Mixed Potential ◽  
Ammonia Sensor ◽  
Ammonia Gas ◽  
Recovery Times ◽  
Response And Recovery ◽  
Increasing Temperature ◽  
Ammonia Gas Sensors

Mixed potential ammonia gas sensors were fabricated by using two sensing materials of Ni3V2O8 and Au-V2O5 as working electrodes, YSZ as electrolyte and platinum as reference electrode. The results have shown that the Ni3V2O8 sensors show cross-sensitivity toward NO gas. However, Au-V2O5 working electrodes displayed a high sensitivity to NH3 as well as fast response and recovery times at high temperatures. Furthermore, the results indicate that the selectivity of Au-V2O5 sensors increases by increasing temperature.

scholarly journals Fumed SiO2-H2SO4-PVA Gel Electrolyte CO Electrochemical Gas Sensor

Chemosensors ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 109
Author(s):  
Yuhang Zhang ◽  
Dongliang Cheng ◽  
Zicheng Wu ◽  
Feihu Li ◽  
Fang Fang ◽  
...  
Keyword(s):  
Gas Sensor ◽  
Gas Sensors ◽  
Water Retention ◽  
Gel Electrolyte ◽  
Co Concentration ◽  
Recovery Times ◽  
Response And Recovery ◽  
Co Sensor ◽  
Pva Gel ◽  
Fumed Sio2

The conventional CO electrochemical gas sensor uses aqueous H2SO4 solution as electrolyte, with inevitable problems, such as the drying and leakage of electrolyte. Thus, research on new alternative electrolytes is an attractive field in electrochemical gas sensors. In this paper, the application of a new fumed SiO2 gel electrolyte was studied in electrochemical gas sensors. The effects of fumed SiO2 and H2SO4 contents on the performance of the CO gas sensor were investigated. The results showed that the optimized composition of the SiO2 gel electrolyte was 4.8% SiO2, 38% H2SO4, and 0.005% polyvinyl alcohol (PVA). Compared with aqueous H2SO4, the gel electrolyte had better water retention ability. The signal current of the sensor was proportional to the CO concentration. The sensitivity to CO was 78.6 nA/ppm, and the response and recovery times were 31 and 38 s, respectively. The detection limit was 2 ppm. The linear range was from 2 to 500 ppm. The gel electrolyte CO sensor possesses equivalent performance to that with aqueous electrolyte.

Sign in / Sign up

Export Citation Format

Share Document