CdO-ZnO nanorices for enhanced and selective formaldehyde gas sensing applications

Ahmad Umar; Ahmed A Ibrahim; Rajesh Kumar; Hassan Algadi; Hasan Albargi; Mabkhoot A Alsairi; Mohsen A M Alhmami; Wen Zeng; Faheem Ahmed; Sheikh Akbar

doi:10.1016/j.envres.2021.111377

CdO-ZnO nanorices for enhanced and selective formaldehyde gas sensing applications

Environ Res. 2021 Sep:200:111377. doi: 10.1016/j.envres.2021.111377. Epub 2021 May 28.

Authors

Ahmad Umar¹, Ahmed A Ibrahim², Rajesh Kumar³, Hassan Algadi⁴, Hasan Albargi⁵, Mabkhoot A Alsairi⁶, Mohsen A M Alhmami⁷, Wen Zeng⁸, Faheem Ahmed⁹, Sheikh Akbar¹⁰

Affiliations

¹ Department of Chemistry, Faculty of Science and Arts, Najran University, Najran, 11001, Saudi Arabia; Promising Centre for Sensors and Electronic Devices (PCSED), Najran University, Najran, 11001, Saudi Arabia. Electronic address: ahmadumar786@gmail.com.
² Department of Chemistry, Faculty of Science and Arts, Najran University, Najran, 11001, Saudi Arabia; Promising Centre for Sensors and Electronic Devices (PCSED), Najran University, Najran, 11001, Saudi Arabia.
³ Department of Chemistry, Jagdish Chandra DAV College, Dasuya, Punjab, 144205, India.
⁴ Promising Centre for Sensors and Electronic Devices (PCSED), Najran University, Najran, 11001, Saudi Arabia; Department of Electrical Engineering, College of Engineering, Najran University, Najran, 11001, Saudi Arabia.
⁵ Promising Centre for Sensors and Electronic Devices (PCSED), Najran University, Najran, 11001, Saudi Arabia; Department of Physics, Faculty of Science and Arts, Najran University, Najran, 11001, Saudi Arabia.
⁶ Promising Centre for Sensors and Electronic Devices (PCSED), Najran University, Najran, 11001, Saudi Arabia; ‏Empty Quarter Research Unit, Department of Chemistry, College of Science and Arts, Sharurah Branch, Najran University, Sharurah, Saudi Arabia.
⁷ Department of Chemistry, Faculty of Science and Arts, Najran University, Najran, 11001, Saudi Arabia.
⁸ College of Materials Science and Engineering, Chongqing University, Chongqing, China.
⁹ Department of Physics, College of Science, King Faisal University, P. O. Box-400, Hofuf, Al-Ahsa, 31982, Saudi Arabia.
¹⁰ Center for Industrial Sensors and Measurements (CISM), Department of Materials Science and Engineering, The Ohio State University, Columbus, OH, 43210, USA.

PMID: 34058181
DOI: 10.1016/j.envres.2021.111377

Abstract

This paper reports synthesis, properties and gas sensing applications of ZnO nanoflowers and CdO-ZnO nanorices prepared by hydrothermal process. The morphological characterizations confirmed the formation of well-defined nanoflowers and nanorices structures for ZnO and CdO-ZnO nanomaterials, respectively. The structural properties revealed the wurtzite hexagonal phase of the synthesized materials. The sensor devices based on ZnO nanoflowers and CdO-ZnO nanorices were fabricated and tested towards various gases including ethanol, methanol, ammonia, carbon monoxide, methane and formaldehyde. The fabricated gas sensor based on CdO-ZnO nanorices exhibited a high response (34.5) towards 300 ppm formaldehyde gas at 350 °C compared to ZnO nanoflowers (14.5) under the same experimental conditions. The response and recovery times for ZnO nanoflowers-based sensor were~9.8 s and ~6 s while for CdO-ZnO based sensor, these were ~10s and ~6s, respectively. A rapid response (34.5) for CdO-ZnO nanorices based formaldehyde gas sensor was observed as compared to other gases such as ammonia (12.3), methanol (16.5), ethanol (20), carbon monoxide (16.3) and methane (12.4), which confirm the high-selectivity towards formaldehyde gas. Finally, a plausible formaldehyde gas sensing mechanism is proposed.

Keywords: CdO–ZnO; Formaldehyde; Gas sensor; Nanoflowers; Nanorices; ZnO.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Ammonia
Formaldehyde
Gases
Nanostructures*
Zinc Oxide*

Substances

Gases
Formaldehyde
Ammonia
Zinc Oxide