The development of chemoresistive gas sensors for environmental and industrial air monitoring as well as medical breath analysis is investigated. Flame-made ZnO nanoparticles (NPs) doped with 1 at% Aluminum exhibited higher sensing performance (response 245, response time ∼ 3 s, and sensitivity 23 ppm−1) than pure ZnO and those made by a hydrothermal method (HT) (56, ∼ 12 s, and 4 ppm−1) for detection of 10 ppm acetone. Furthermore, their sensing response of ∼10 to 0.1 ppm of acetone at 90% RH is superior to other metal oxide sensors and they feature good acetone selectivity to other compounds (including NH3, isoprene and CO). Characterization by N2 adsorption, X-ray photoelectron and UV–vis spectroscopies reveals that the improved sensing performance of flame-made Al-doped ZnO NPs is associated primarily to a higher density of oxygen vacancies than pure ZnO and all HT-made NPs. This leads to a greater number of adsorbed oxygen ions on the surfaces of Al-doped ZnO NPs, which can react with acetone molecules.
Bibliographical noteFunding Information:
This work was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF), and it was funded by the Ministry of Science, ICT & Future Planning ( NFR-2017M3A9F1052297 ). ATG and SEP gratefully acknowledge funding by the Swiss National Science Foundation (grant # 200021_159763/1 ).
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Surfaces, Coatings and Films
- Metals and Alloys
- Electrical and Electronic Engineering
- Materials Chemistry