Highly sensitive and selective detection of ethanol vapor using flame-spray-made CeO<inf>x</inf>-doped SnO<inf>2</inf>nanoparticulate thick films

Abstract

© 2017 Elsevier B.V. In the present work, flame-spray-made CeOx-doped SnO2nanoparticles with 0.1–1 wt% Ce contents were systematically studied for ethanol detection. Structural characterizations by electron microscopy, Nitrogen adsorption and X-ray analysis indicated that SnO2nanoparticles were highly crystalline with tetragonal structure and CeOxcrystallites with mixed Ce3+and Ce4+oxidation states should form a solid solution with SnO2matrix. The sensing films were tested towards 3–200 ppm ethanol at operating temperatures ranging from 200 to 400 °C in dry air. Gas-sensing results demonstrated that the SnO2sensing film with the optimal Ce content of 0.5 wt% exhibited a very high response of ∼2654–200 ppm ethanol with a short response time of 1.1 s at the optimal operating temperature of 350 °C. Moreover, the optimal sensor displayed high ethanol selectivity against C3H6O, CH4, H2, NO2, H2S and H2O. Therefore, the flame-made CeOx-doped SnO2sensor is a promising candidate as a sensitive and selective ethanol detector for drunk-driving and biomedical applications.