Tuning the selectivity of NH3 gas sensing response using Cu-doped ZnO nanostructures

• Published in: Sensors and actuators. A. Physical. 2018-01, Vol.269, p.331-341
• Main Authors: Ganesh, R. Sankar, Durgadevi, E., Navaneethan, M., Patil, V.L., Ponnusamy, S., Muthamizhchelvan, C., Kawasaki, S., Patil, P.S., Hayakawa, Y.
• Format: Article
• Language: English
• Subjects: Ammonia; BET analysis; Cu-doped ZnO; Gas sensing; Nanostructures
• ISSN: 0924-4247; 1873-3069
• DOI: 10.1016/j.sna.2017.11.042

[Display omitted] •ZnO nanorods, Cu-doped ZnO nanoflower and nanoellipsoids were successfully synthesized.•CZO nanoellipsoids showed enhanced oxygen vacancies compared to undoped ZnO.•Cu-doped ZnO (6%) showed maximum response of 32.32 for 100ppm at 150°C.•Cu-doped ZnO showed long-term stability and repeatability.•Fast response and recovery time was obtained. Copper-doped ZnO (CZO) nanoflower and nanoellipsoids were synthesized by hydrothermal method. Field emission electron microscopy and transmission electron microscopy revealed that the flower-like morphology of undoped ZnO transformed into nanoellipsoids upon incorporation of copper (Cu) in ZnO. Raman spectra of copper- doped ZnO showed E2L peak shift compared with undoped ZnO nanoflower which indicated enhanced oxygen or zinc vacancy in copper-doped ZnO. Low-temperature ammonia gas sensing properties based on copper-doped ZnO were systematically studied. Cu-doped ZnO (6wt%) showed enhanced selectivity compared with other copper doping (wt%). Furthermore, the Cu-doped ZnO showed an excellent response and recovery time at a low concentration of ammonia (10ppm). Cu-doped ZnO showed better long-term stability and reproducibility towards ammonia gas.