Enhancement of sensitivity in gas chemiresistors based on carbon nanotube surface functionalized with noble metal (Au, Pt) nanoclusters

Abstract

Multiwalled carbon nanotube (MWCNT) films have been fabricated by using plasma-enhanced chemical vapor deposition system onto Cr–Au patterned alumina substrates, provided with 3nm thick Fe growth catalyst, for NO2 and NH3 gas sensing applications, at sensor temperature in the range of 100–250°C. Nanoclusters of noble metal surface catalysts (Au and Pt) have been sputtered on the surface of MWCNTs to enhance the gas sensitivity with respect to unfunctionalized carbon nanotube films. It was found that the gas sensitivity of Pt- and Au-functionalized MWCNT gas sensors significantly improved by a factor up to an order of magnitude through a spillover effect for NH3 and NO2 gas detections, respectively. The metal-functionalized MWCNT sensors exhibit very high gas sensitivity, fast response, reversibility, good repeatability, and sub-ppm range detection limit with the sensing properties of the MWCNT films tailored by surface catalyst used to functionalize the MWCNT sensors.

Electrophoretic deposition of Au NPs on CNT networks for sensitive NO<sub>2</sub> detection

“…Among various metal NPs, Au-functionalized CNT-based resistive gas sensors show the best sensitivity and selectivity towards NO 2 gas detection (Penza et al, 2007).…”

Crystallization of Lennard-Jones nanodroplets: From near melting to deeply supercooled

“…Nanoclusters, small clusters comprising tens to millions of atoms, are used in a variety of settings, such as tuning the optical [1][2][3] and electronic properties of materials [2,4], biolabeling and imaging [5], catalysis [6,7], and chemical sensing [8]. The various structures to which nanoclusters solidify, as well as their surface properties, bear a strong impact on their function [9].…”

Gas Sensors Based on Decorated Carbon Nanotubes

“…Using sputtering (Lu et al 2004) and (Sayago et al 2007) SWCNTS were decorated with Pd. MWCNTs were decorated with Ti (Gelamo et al 2009), Pt and Au (Penza et al 2007). The differences in chemical reactivities of metal nanoparticles resulted in selective detection of gases like of H 2 , CH 4 , CO, H 2 S, NH 3 , NO 2 and O 2 .…”