A Photoactivated Gas Detector for Toluene Sensing at Room Temperature Based on New Coral-Like ZnO Nanostructure Arrays.
A photoactivated gas detector operated at room temperature was microfabricated using a simple hydrothermal method. We report that the photoactivated gas detector can detect toluene using a UV illumination of 2 μW/cm². By ultraviolet (UV) illumination, gas detectors sense toluene at room temperature without heating. A significant enhancement of detector sensitivity is achieved because of the high surface-area-to-volume ratio of the morphology of the coral-like ZnO nanorods arrays (NRAs) and the increased number of photo-induced oxygen ions under UV illumination. The corresponding sensitivity (ΔR/R₀) of the detector based on coral-like ZnO NRAs is enhanced by approximately 1022% compared to that of thin-film detectors. The proposed detector greatly extends the dynamic range of detection of metal-oxide-based detectors for gas sensing applications. We report the first-ever detection of toluene with a novel coral-like NRAs gas detector at room temperature. A sensing mechanism model is also proposed to explain the sensing responses of gas detectors based on coral-like ZnO NRAs.
Graduate Institute of Electronics Engineering, National Taiwan University, Taipei City 10617, Taiwan. likoyeh@gmail.com.
Li-Ko
LK
Yeh
Graduate Institute of Electronics Engineering, National Taiwan University, Taipei City 10617, Taiwan. life2145@hotmail.com.
Jie-Chun
JC
Luo
Department of Chemical Engineering, National Taiwan University, Taipei City 10617, Taiwan. b99504035@ntu.edu.tw.
Min-Chun
MC
Chen
Graduate Institute of Applied Mechanics, National Taiwan University, Taipei City 10617, Taiwan. ki781219@gmail.com.
Chih-Hung
CH
Wu
Graduate Institute of Applied Mechanics, National Taiwan University, Taipei City 10617, Taiwan. jchen@ntu.edu.tw.
Jian-Zhang
JZ
Chen
Department of Electrical Engineering, National Taiwan University, Taipei City 10617, Taiwan. iccheng@ntu.edu.tw.
I-Chun
IC
Cheng
Department of Chemical Engineering, National Taiwan University, Taipei City 10617, Taiwan. chsu@ntu.edu.tw.
Cheng-Che
CC
Hsu
Graduate Institute of Electronics Engineering, National Taiwan University, Taipei City 10617, Taiwan. wctian@ntu.edu.tw.|Department of Electrical Engineering, National Taiwan University, Taipei City 10617, Taiwan. wctian@ntu.edu.tw.|Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei City 10617, Taiwan. wctian@ntu.edu.tw.
Wei-Cheng
WC
Tian
ZnO coral-like nanostructures; ZnO gas detector; photoactivation; room temperature sensing