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 3 mol% 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 3 mol% CuO/SnO2 composite has the best selectivity and sensitivity for BTEX. At the optimal working temperature of 280 degrees C, the response value of the sensor to 50 ppm BTEX are more than 6 times. Excellent gas sensitive performance of 3 mol% CuO/SnO2 based sensor to BTEX belongs to the addition of catalyst CuO. (C) 2015 Elsevier B.V. All rights reserved.