Selective Detection of NO and NO2 with CNTs-Based Ionization Sensor Array

Abstract

The accurate detection of NOx is an important issue, because nitrogen oxides are not only environmental pollutants, but also harm to human health. An array composed of two carbon nanotubes (CNTs)-based ionization sensors with different separations is proposed for NO and NO2 selective detection. The experimental results indicate that the CNTs-based ionization sensor has an intrinsic, monotonically decreasing response to NO or NO2. The sensor with 80 µm separations and 100 µm separations exhibited the highest sensitivity of −0.11 nA/ppm to 300 ppm NO and −0.49 nA /ppm to 70 ppm NO2, respectively. Although the effect of the NO2 concentration on the NO response is much stronger than that of NO on NO2, the array of these two sensors still exhibits the ability to simultaneously detect the concentrations of NO and NO2 in a gas mixture without component separation.

Ionization Gas Sensor Using Suspended Carbon Nanotube Beams

“…It is important to acknowledge that the operation of the presented ionization sensor is not readily applicable in all sensing systems due to the still high breakdown voltages required. However, in comparison to other CNT-based ionization sensors [20,22,23], the presented suspended CNT sensor demonstrates lower breakdown voltages and represents a step towards mitigating this limitation. Methods to reduce the breakdown voltage even further are being investigated to widen the applications of the sensor.…”

“…Other CNT-based ionization sensors have been developed to detect humidity, NO 2 , etc. [21][22][23][24]. In all the articles mentioned above, the CNTs are grown vertically using very high temperature-based vapor deposition techniques.…”

Highly Sensitive H2 Sensors Based on Co3O4/PEI‐CNTs at Room Temperature

“…Nguyen synthesized CNT films via CVD and displayed fast response and high sensitivity for NH 3 sensing [30,31]. CNTs also have been applied in the NO 2 gas sensor, and the NO 2 surface reaction can be explained by NO and NO 3 which are produced on the surface [32][33][34].…”

Editorial for the Special Issue on Carbon Based Electronic Devices

“…A wide spectra of carbon materials and a wide range of applications are described in the present issue. As per material type, papers deal with graphene and graphene-oxide [1][2][3][4], carbon nanotubes [2,5,6] and with other forms of carbon, such as porous carbon [7] and nanofibers [8,9]. A plethora of devices are witnessing the versatility of carbon materials: supercapacitors [1,9], non-volatile memories [8], pressure sensors [2,7], field-effect transistors [10], white-light photosensors [3], cold cathode electron emitters [5], gas and humidity detectors [6,11], MEMS and NEMS [12], carbon based inks for 3D microfluidic MEMS [13], transparent conductive electrodes [4].…”

“…Kim et al [5] focused their work on the fabrication of stable CNT cold emitter using an aging technique. The last research paper is presented by Song et al [6] and focuses on the ability of a two-nanotube sensor to selectively detect NO and NO 2 .…”