High-sensitive metal oxide gas sensor for BTEX gases based on ternary composite of Ce _x Mn_1−x O₂/SnO₂

Abstract

A sensitive gas sensor based on a ternary composite of Ce x Mn 1−x O 2 /SnO 2 was used for BTEX detection. The ternary Ce x Mn 1−x O 2 /SnO 2 was synthesized via hydrothermal and immersion method and characterized by high resolution transmission electron microscopy and x-ray photoelectron spectroscopy. 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 (benzene, toluene, ethylbenzene and xylene) 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 Ce x Mn 1−x O 2 and heterogeneous effect at the interphase of the Ce x Mn 1−x O 2 -SnO 2 . The gas sensor developed in this paper provide a possible further application in BTEX gases, especially in ppb-level detection.

Nanomaterial-based VOC sensing applications and a deep dive into their developmental trends

“…A crucial advantage of nanomaterials is that their properties can be altered and fine-tuned according to the need. 124–127 Sensitivity, selectivity, a lower limit of detection (LOD: the lowest quantity/concentration of a given analyte that can be reliably detected), linear range, operating temperature, response/recovery times, reproducibility and stability are some of the key parameters when considering the efficiency of a gas sensor. 128 The sensor response is a measure of change in parameters like resistance, current, frequency, etc.…”