Highly sensitive acetone sensors based on flame-spray-made La2O3-doped SnO2 nanoparticulate thick films

In the present work, flame-spray-made La2O3-doped SnO2 nanoparticles with 0.1-2 wt% La contents were systematically studied for acetone detection. The particle and sensing film properties were characterized by X-ray diffraction, nitrogen adsorption, electron microscopy, energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy. The sensing films were tested towards 0.1-400 ppm acetone at operating temperatures ranging from 150 to 400 degrees C in dry air. Gas-sensing results demonstrated that the SnO2 sensing film with the optimal La content of 0.5 wt% exhibited a very high response of 3626 toward 400 ppm acetone with a short response time of 2.8 s at the optimal operating temperature of 350 degrees C. Moreover, the sensors displayed high acetone selectivity against SO2, H2S, NO2, C6H6, C7H8, C8H10 and CH2O. Therefore, the La2O3-doped SnO2 sensors are promising for sensitive and selective detections of acetone at low concentrations. (C) 2018 Elsevier B.V. All rights reserved.