Sensors, Vol. 20, Pages 5602: New Insights towards High-Temperature Ethanol-Sensing Mechanism of ZnO-Based Chemiresistors
Sensors, Vol. 20, Pages 5602: New Insights towards High-Temperature Ethanol-Sensing Mechanism of ZnO-Based Chemiresistors
Sensors doi: 10.3390/s20195602
Authors:
Lesia Piliai
David Tomeček
Martin Hruška
Ivan Khalakhan
Jaroslava Nováková
Přemysl Fitl
Roman Yatskiv
Jan Grym
Mykhailo Vorokhta
Iva Matolínová
Martin Vrňata
In this work, we investigate ethanol (EtOH)-sensing mechanisms of a ZnO nanorod (NRs)-based chemiresistor using a near-ambient-pressure X-ray photoelectron spectroscopy (NAP-XPS). First, the ZnO NRs-based sensor was constructed, showing good performance on interaction with 100 ppm of EtOH in the ambient air at 327 °C. Then, the same ZnO NRs film was investigated by NAP-XPS in the presence of 1 mbar oxygen, simulating the ambient air atmosphere and O2/EtOH mixture at the same temperature. The partial pressure of EtOH was 0.1 mbar, which corresponded to the partial pressure of 100 ppm of analytes in the ambient air. To better understand the EtOH-sensing mechanism, the NAP-XPS spectra were also studied on exposure to O2/EtOH/H2O and O2/MeCHO (MeCHO = acetaldehyde) mixtures. Our results revealed that the reaction of EtOH with chemisorbed oxygen on the surface of ZnO NRs follows the acetaldehyde pathway. It was also demonstrated that, during the sensing process, the surface becomes contaminated by different products of MeCHO decomposition, which decreases dc-sensor performance. However, the ac performance does not seem ...
Source: Sensors - Category: Biotechnology Authors: Lesia Piliai David Tome ček Martin Hru ška Ivan Khalakhan Jaroslava Nov áková P řemysl Fitl Roman Yatskiv Jan Grym Mykhailo Vorokhta Iva Matol ínová Martin Vr ňata Tags: Article Source Type: research