A carbonaceous chemical filter for the selective detection of NO2 in the environment

作者：Dubois M^*; Brunet J; Pauly A; Spinelle L; Ndiaye A; Guerin K; Varenne C; Lauron B; Klyushin A Yu; Vinogradov A S

来源：Carbon, 2013, 52: 17-29.

DOI：10.1016/j.carbon.2012.08.067

In order to achieve the selective detection of NO2 in the environment, a chemical filter is added to a semiconductor gas sensor that is very sensitive to oxidizing gases in the gas flow. The aim is to remove ozone (O-3), the main interfering oxidizing gas for NO2 detection before its measurement by a phthalocyanine sensor. The first parameter for the carbon material as a filter is the specific surface area (SSA), which should be high enough to ensure interaction with O-3 and low enough to avoid interaction with NO2. The key role of surface oxygenated groups and dangling bonds was underlined by NEXAFS and EPR, respectively. A mixture of nanocones/nanodiscs (20/70% w/w) with SSA of 30 m(2) g(-1) with both structural and electronic defects is found to be the most efficient filter and was used upstream of a phthalocyanine sensor. The lifetime of the chemical filter was investigated and a strategy to increase it is described. Raman spectroscopy, EPR and NEXAFS allow the reactivity of the carbon with NO2 and O-3 in the 10-1000 ppb concentration range to be studied.

• 出版日期2013-2