Development of NH₃ Gas Sensors at Room Temperature Based on Modified Carbon Nanotubes

Abstract

Multiwalled carbon nanotubes (CNTs) were modified with the Hummers method and coated onto Pt electrodes patterned on SiO 2 /Si(001) surface to fabricate chemical sensors. The modified CNTs showed a different structure and increased number of defects compared with pristine CNTs, these properties facilitated the adsorption of NH 3 gas molecules on the CNT surfaces. NH 3 gas sensing results indicate that the sensor exhibited an enhanced response to gas at room temperature. The response of the modified CNT-based sensor was 10 times higher than that of pristine CNT-based sensors.

Recent Progress in Nanostructured Functional Materials and Their Applications II

“…5. In the third paper, 183) development of gas sensors for the NH 3 using the carbon nanotubes is shown, in which multiwalled carbon nanotubes (CNTs) were coated onto Pt electrodes patterned on SiO 2 /Si(001) surface. The fourth paper 184) reports preparations of natural rubber-based electromagnetic shielding materials for coating application, in which expanded graphite was prepared and dispersed in the polyaniline/natural rubber matrix.…”

Recent trends in gas sensingviacarbon nanomaterials: outlook and challenges

“…Signicant research on the detection of NH 3 using CNT-based chemiresistive sensors has been performed. [149][150][151][152][153][154] In one of the studies, Ansari et al observed that SWCNTs functionalized using nitric acid (f-SWCNTs) showed a higher response than pristine SWCNTs 153 together with a long recovery time due to the strong chemical bonding of the gas molecules with the functional groups of SWCNTs. In another work, Schütt and coworkers synthesized tetrapodal ZnO networks (ZnO-T) decorated with MWCNTs as an NH 3 sensing material.…”

Gas Sensing Properties of High-Purity Semiconducting Single-Walled Carbon Nanotubes for NH3, H2, and NO

“…32,33,[35][36][37] Additionally, it can detect NH 3 , which is typically difficult to detect using the metal oxide gas sensors. 38,39 Single-walled CNTs (SWCNTs) exhibit metallic and semiconducting electrical properties depending on the chirality of the cylindrically wrapped graphene sheet. 40 The metallic and semiconducting SWCNTs were mixed in the synthesized mixture in a ratio of 1:2 based on the chirality-based analysis.…”