Room temperature gas sensing of p-type TeO2 nanowires

Abstract

Tellurium dioxide (TeO2) nanowires with a tetragonal structure have been grown by thermally evaporating tellurium metal at 400°C in air. The nanowires produced have diameters ranging from 30to200nm and have lengths of several tens of micrometers. Gas sensors were fabricated using the obtained TeO2 nanowires. The sensing behavior to NO2, NH3, and H2S gases at room temperature showed typical characteristics of a p-type semiconductor. The results demonstrate the potential to develop TeO2 nanowire based gas sensors with low power consumption.

Room temperature gas sensing properties of SnO2/multiwall-carbon-nanotube composite nanofibers

“…10 P-type TeO 2 nanowires have been investigated for sensing ammonia and nitrogen dioxide at room temperature. 11 The complexity and cost of fabrication as well as power consumption may hinder their applications. Komalkov et al 7 reported the O 2 and CO sensing properties based on an individual SnO 2 nanowire and a detection limit of a few 100 ppm for CO in dry air at 300°C was measured.…”

Formation of Oxide Nanowires by Thermal Evaporation and Their Application to Gas Sensors

“…Figure 14 shows the typical SEM image of the nanowires that we formed by thermal evaporation of Te grains in ambient air (Liu et al, 2007;. The nanowires are several tens of micrometers in length and 30-200 nm in diameter.…”

“…This method, in which nanowires are formed in an ambient air, is very simple and was applied to the formation of TeO 2 nanowires (Liu et al, 2007;. As shown in Fig.1(b), a desirable amount of tellurium grains at a high purity of 99.999% was placed in an alumina crucible 30mm in height and 20mm in diameter.…”

Enhanced Gas Sensing Properties of Pt-Loaded TeO2Nanorods

“…7,8 TeO 2 nanorods have been synthesized by the thermal evaporation of Te powders, 9 laser ablation of Te, 7 and direct thermal oxidation of Te at ambient pressure in a flow of O 2 without the presence of a catalyst. 10 Microcrystals of TeO 2 have been synthesized by the hydrolysis of tellurium isopropoxide in the presence of a tetra alkyl ammonium bromide solution.…”

“…After the TeO 2 nanorods are exposed to NO 2 gas, NO 2 molecules are adsorbed on the TeO 2 surface, which trap the lone-pair electrons of the dangling bond on the TeO 2 surface. 28 This results in the formation of a free hole, as shown in the following equations:…”