Optical waveguide structure design of Non-dispersive Infrared (NDIR) CO2 gas sensor for high-sensitivity

A tin oxide (SnO2) and reduced graphene oxide (rGO) hybrid composite gas sensor for high-performance carbon dioxide (CO2) gas detection at room temperature was studied. Since it can be used independently from a heater, it emerges as a promising candidate for reducing the complexity of device circuitry, packaging size, and fabrication cost; furthermore, it favors integration into portable devices with a low energy density battery. In this study, SnO2-rGO was prepared via an in-situ chemical reduction route. Dedicated material characterization techniques including field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), energy dispersive X-ray (EDX) spectroscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) were conducted. The gas sensor based on the synthesized hybrid composite was successfully tested over a wide range of carbon dioxide concentrations where it exhibited excellent response magnitudes, good linearity, and low detection limit. The synergistic effect can explain the obtained hybrid gas sensor’s prominent sensing properties between SnO2 and rGO that provide excellent charge transport capability and an abundance of sensing sites.

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Enhanced Characteristics of Nondispersive Infrared CO2 Gas Sensor by Deposition of Hydrophobic Thin Film

Proceedings ◽

10.3390/proceedings1040410 ◽

2017 ◽

Vol 1 (4) ◽

pp. 410 ◽

Cited By ~ 1

Author(s):

Jinho Kim ◽

Jayoung Lee ◽

Keunheon Lee ◽

Seunghwan Yi

Keyword(s):

Thin Film ◽

Gas Sensor ◽

Co2 Gas ◽

Co2 Gas Sensor

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Double Notched Long-Period Fiber Grating Characterization for CO2 Gas Sensing Applications †

Sensors ◽

10.3390/s18103206 ◽

2018 ◽

Vol 18 (10) ◽

pp. 3206 ◽

Cited By ~ 2

Author(s):

Hsiang-Chang Hsu ◽

Tso-Sheng Hsieh ◽

Tzu-Hsuan Huang ◽

Liren Tsai ◽

Chia-Chin Chiang

Keyword(s):

Gas Sensor ◽

Transmission Loss ◽

Gas Sensing ◽

Fiber Grating ◽

Co2 Gas ◽

Long Period Fiber Grating ◽

Long Period ◽

Sensing Applications ◽

Co2 Gas Sensor ◽

Period Fiber Grating

In this study, we applied a double-sided inductively coupled plasma (ICP) process to nanostructure long-period fiber grating (LPFG) in order to fabricate a double-notched LPFG (DNLPFG) sensor with a double-sided surface corrugated periodic grating. Using the sol-gel method, we also added thymol blue and ZnO to form a gas sensing layer, thus producing a DNLPFG CO2 gas sensor. The resulting sensor is the first double-sided etching sensor used to measure CO2. The experimental results showed that as the CO2 concentration increased, the transmission loss increased, and that the smaller the fiber diameter, the greater the sensitivity and the greater the change in transmission loss. When the diameter of the fiber was 32 μm (and the period was 570 μm) and the perfusion rate of CO2 gas was 15%, the maximum loss variation of up to 3.881 dB was achieved, while the sensitivity was 0.2146 dB/% and the linearity was 0.992. These results demonstrate that the DNLPG CO2 gas sensor is highly sensitive.

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Micro CO2 Sensor Based on Li2CO3, Pt | Li3PO4 | Pt, Li2TiO3-TiO2 Structure

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.44-47.2747 ◽

2010 ◽

Vol 44-47 ◽

pp. 2747-2751

Author(s):

Hai Rong Wang ◽

Jun Qiang Ren ◽

Guo Liang Sun ◽

Di Cen

Keyword(s):

Solid Electrolyte ◽

Gas Sensor ◽

Experimental Results ◽

Al2o3 Substrate ◽

Reference Electrodes ◽

Co2 Gas ◽

Speed Of Response ◽

Co2 Gas Sensor ◽

Improved Performance ◽

Mems Process

This paper presents a micro solid electrolyte CO2 gas sensor in which Li2CO3, Li2TiO3-TiO2 serves as sensing and reference electrodes respectively, and the Li3PO4 film acts as the electrolyte. The sensor was constructed in the sequent layers of O2, CO2, Li2CO3, Pt | Li3PO4 | Pt, Li2TiO3-TiO2, O2, CO2 on the Al2O3 substrate by MEMS process. Experimental results indicate that the micro solid-electrolyte CO2 gas sensor has a relatively rapid speed of response. By discussions, we may find that the improved performance will be realized by optimizing the primary parameters of the sensor.

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