Chemiresistive Sensor Based on Zinc Oxide Nanoflakes for CO₂ Detection

Abstract

Ultrafast detection of dynamic variations in the carbon dioxide (CO 2 ) gas concentration with good sensitivity is crucial in many applications that range from respiration monitoring to fire detection. However, the chemical inertness of the CO 2 sensor makes its detection with high sensitivity quite difficult, and only a few materials were reported that can sense CO 2 effectively. Nevertheless, the sensors based on these materials exhibited very low sensitivity with large response times, and thus they are not suitable for many practical applications. Here, we report a highly sensitive, reversible, and ultrafast detection of CO 2 gas in air using a resistive gas sensor based on ZnO nanoflakes. Excellent sensitivity (0.1125 ppm −1 for 600 ppm) with ultrafast response (<20 s) is observed upon exposure of the sensor to 200−1025 ppm of CO 2 at 250 °C. The sensing mechanism of the device is explained by the oxygen vacancy model. Further, the effect of the temperature and cross-sensitivity of the sensor to other gases were experimentally investigated. Being highly sensitive and faster, this CO 2 sensor can be utilized in numerous applications where high response and recovery times along with good sensitivity are extremely important.

Ultra-sensitive detection of H₂S with 2D ZnO nanostructures

“…The protocol for device fabrication and sensing experiments were explained in our previous reports [8,9]. MOL2NET, 2019, 5, ISSN: 2624-5078 2 http://sciforum.net/conference/mol2net-05…”

Rapid detection of target gases with an early prediction approach

“…The protocol for sensor fabrication and gas sensing experiments were explained in our previous reports [3][4][5].…”

Metal–Organic Frameworks Materials for Capacitive Gas Sensors

“…Some studies have shown that the concentration of carbon dioxide in the atmosphere has increased from 310 to 380 ppm in the past half century. [66,67] In many fields, such as submarine technology, aerospace, mining, and rescue operations, it is important to detect the low-concentration of CO 2 in the confined space, [68,69] therefore, it is necessary to continuously detect the low-concentration of CO 2 . [70] The following summarizes the research of MOFs materials as CO 2 capacitive sensors.…”