Enhanced acetone gas-sensing properties of NiO–SnO2 nanocomposites

Abstract

In this study we synthesized NiO–SnO2 nanocomposites with various contents of SnO2 (33, 50, and 66 wt%) and studied their gas-sensing behaviors. Commercial SnO2 and NiO powders with near-spherical morphology and surface areas of 6.80 and 1.47 m2/g, respectively, were hydrothermally treated at 175 °C for 16 h. Based on transmission electron microscopy observations, morphologies of SnO2 and NiO powders were transformed into nanoparticles (NPs) and nanorods (NRs), respectively. Acetone and ethanol gas-sensing investigations were carried out at various temperatures. At 350 °C, a sensor with 66 wt% SnO2 revealed enhanced output to acetone gas. Besides, the sensor exhibited good selectivity for this gas in the presence of interfering gases. This study demonstrated the significant dependence of the sensing characteristics on the chemical composition and the need for composition optimization to achieve the highest sensitivity to the target gas.