High-sensitive metal oxide gas sensor for BTEX gases based on ternary composite of CexMn1-xO2/SnO2

A sensitive gas sensor based on a ternary composite of CexMn1-xO2/SnO2 for application in BTEX detection. The ternary CexMn1-xO2/SnO2 was synthesized via hydrothermal and immersion method and characterized by high resolution transmission electron microscopy (HRTEM) and X-ray photoelectron spectroscopy (XPS). The gas sensor performances were measured on a designed flow-through microsystem consisted of a dynamic multiple gas handling unit, a test gas preheater, an olive-like test chamber and a data analysis apparatus. The developed gas sensor shows a high sensitivity towards BTEX gases with a linear ranging from 100 to 600 ppb at optimal temperature. The sensor exhibited relative selectivity to BTEX gases compared to other VOC components. The sensing mechanism can be concluded as the "spillover effects" of CexMn1-xO2 and heterogeneous effect at the interphase of the CexMn1-xO2-SnO2. The gas sensor developed in this paper provide a possible further application in BTEX gases, especially in ppb-level detection.