Enhanced Detection of Ethanol in a Humid Ambient Using Al2O3-Doped Cactus-Like ZnO Nanoflowers With Gold Nanoparticles

Aluminum oxide-doped (Al2O3-doped) cactus-like ZnO nanoflowers with gold (Au) nanoparticles (NPs) are grown on an aluminum (Al) substrate using a hydrothermal method to detect ethanol sensing in atmospheres with various degrees of relative humidity (RH). The microstructural measurement shows that the novel morphology cactus-like ZnO nanoflowers are approximately 3.5 mu m high and Au NP is around 20 nm, highly dense and very uniform. The sensing performance is as high as 74.65% for 10 ppm ethanol and 42.09% for a low concentration of 2 ppm at 200 degrees C. A comparison of ethanol detection properties in atmospheres with various degrees of RH shows that the response of cactus-like ZnO nanoflowers to 10 ppm ethanol decreases from 55.27% at 25% RH to 47.64% at 85% RH. The response of traditional pure ZnO nanowires decreases from 44.65% to 4.98 at 25% to 85% RH. The cactus-like ZnO nanoflowers have better resistance to moisture. The novel cactus-like ZnO nanoflowers are sufficiently sensitive to ethanol in an atmosphere with high humidity to enable effective and accurate analysis of the amount of alcohol in breath.