Recognition of binary mixture of NO2 and NO gases using a chemiresistive sensors array combined with principal component analysis

Abstract

Novel room-temperature type chemiresistive gas sensor arrays consisted of two, three or four metal oxide semiconductor (MOS) gas sensors that were constructed using iron oxide/multi-walled carbon nanotubes/tungsten oxide (Fe2O3/MWCNTs/WO3), surface Au-, Pd- and Ag- modified films as sensing materials. Principal component analysis (PCA) coupled with various MOS chemiresistive gas sensor arrays were used to analyze the obtained data under testing conditions of binary mixture gases containing various composition of NO and NO2 at room-temperature. The careful pattern recognition of sensing data obtained with a chemiresistive gas sensor array consisting of three MOS sensors made it possible to qualitatively differentiate the variation in the composition of gas species in a binary mixture of NO2 and NO gases with related to their concentrations.