▎ 摘　　要

This paper investigates the alpha-Fe2O3/reduced graphene oxide (rGO) nanocomposite as a volatile organic compounds (VOCs) sensor. The alpha-Fe2O3/reduced graphene oxide nanocomposites of about 370 nm thickness were synthesized by a spray method with different rGO contents (3%, 4%, and 5%) on SiO2/Si substrates. The samples were structurally and morphologically characterized by x-ray diffraction, and field emission scanning electron microscopy. These analyses showed that an increase in rGO content decreases the crystallinity of the samples. In order to study the VOCs sensing properties, the sensitivity and selectivity of the samples were tested with different VOCs vapors including ethanol, methanol, toluene, benzene, and formic acid in the temperature range of 200-400A degrees C. The results show that the alpha-Fe2O3/rGO nanocomposites are more selective to ethanol than the other vapors, while an increase in rGO content decreases the sensitivity of the samples. The alpha-Fe2O3/rGO (3%)-based ethanol sensor also shows a good stability with respect to relative humidity in the range of 20-50% with a 1-ppm detection limit at the operating temperature of 280A degrees C.