Enhanced BTEX gas-sensing performance of CuO/SnO2 composite

Abstract

Series CuO/SnO2 composites for selectively sensing BTEX (benzene, toluene, ethylbenzene, and xylol) designed by a principle of catalytic oxidation were synthesized. The sensing materials were prepared by a facile microwave-assisted approach. The composites were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HRTEM). TEM results reveal that the as-prepared SnO2 are nanoscaled porous particles. For 3mol% CuO/SnO2 composite, the existence of CuO nanoparticles is proved by EDS and HRTEM. Gas sensing results of side-heating sensors display that the CuO/SnO2 composites sensors compared with pristine SnO2 sensor have much better responses to BTEX rather than other VOCs such as ethanol, acetone, methanol, formaldehyde and ammonia. Among these CuO/SnO2 composites, the sensor based on 3mol% CuO/SnO2 composite has the best selectivity and sensitivity for BTEX. At the optimal working temperature of 280°C, the response value of the sensor to 50ppm BTEX are more than 6 times. Excellent gas sensitive performance of 3mol% CuO/SnO2 based sensor to BTEX belongs to the addition of catalyst CuO.