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 μm 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 °C. A comparison of ethanol detection properties in atmospheres with various degrees of RI! 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 cactuslike 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.