ZnO has been studied intensely for chemical sensors due to its high sensitivity and fast response. Here, we present a simple approach to precisely control oxygen vacancy contents to provide significantly enhanced acetone sensing performance of commercial ZnO nanopowders. A combination of H2O2 treatment and thermal annealing produces optimal surface defects with oxygen vacancies on the ZnO nanoparticles (NPs). The highest response of ∼27,562 was achieved for 10 ppm acetone in 0.125 M H2O2 treated/annealed ZnO NPs at the optimal working temperature of 400 °C, which is significantly higher than that of reported so far in various acetone sensors based on metal oxide semiconductors (MOSs). Furthermore, first-principles calculations indicate that pre-adsorbed O formed on the surface of H2O2 treated ZnO NPs can provide favorable adsorption energy, especially for acetone detection, due to strong bidentate bonding between carbonyl C atom of acetone molecules and pre-adsorbed O on the ZnO surface. Our study demonstrates that controlling surface oxygen vacancies by H2O2 treatment and re-annealing at optimal temperature is an effective method to improve the sensing properties of commercial MOS materials.
Bibliographical noteFunding Information:
This research was supported by the Technology Innovation Program (No. 20013621, Center for Super Critical Material Industrial Technology) funded by the Ministry of Trade, Industry & Energy (MOTIE, Republic of Korea), the Priority Research Centers Program (2019R1A6A1A11 055660), and the Basic Science Research Program (2017 M3A9F1052297) through the National Research Foundation of Korea (NRF), funded by the Republic of Korean Government (Ministry of Science and ICT). Jong Hyeok PARK acknowledges the support from the International Energy Joint R&D Program of the Korea Institute of Energy Technology Evaluation and Planning (KETEP), granted financial resource from the Ministry of Trade, Industry & Energy, Republic of Korea (20208510010310). Hyun-Sook LEE gratefully acknowledges the support from the Basic Research in Science and Engineering Program of the NRF (2021R1A2C1013690).
© 2022, The Author(s).
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites