Role of the Exposed Polar Facets in the Performance of Thermally and UV Activated ZnO Nanostructured Gas Sensors
Open Access
- 15 August 2013
- journal article
- research article
- Published by American Chemical Society (ACS) in The Journal of Physical Chemistry C
- Vol. 117 (34), 17850-17858
- https://doi.org/10.1021/jp4061895
Abstract
ZnO nanostructures with different morphologies (nanowires, nanodisks, and nanostars) were synthesized hydrothermally. Gas sensing properties of the as-grown nanostructures were investigated under thermal and UV activation. The performance of the ZnO nanodisk gas sensor was found to be superior to that of other nanostructures (Sg ∼ 3700% to 300 ppm ethanol and response time and recovery time of 8 and 13 s). The enhancement in sensitivity is attributed to the surface polarities of the different structures on the nanoscale. Furthermore, the selectivity of the gas sensors can be achieved by controlling the UV intensity used to activate these sensors. The highest sensitivity value for ethanol, isopropanol, acetone, and toluene are recorded at the optimal UV intensity of 1.6, 2.4, 3.2, and 4 mW/cm2, respectively. Finally, the UV activation mechanism for metal oxide gas sensors is compared with the thermal activation process. The UV activation of analytes based on solution processed ZnO structures pave the way for better quality gas sensors.Keywords
This publication has 41 references indexed in Scilit:
- Local vapor transport synthesis of zinc oxide nanowires for ultraviolet-enhanced gas sensingNanotechnology, 2010
- Brush-Like Hierarchical ZnO Nanostructures: Synthesis, Photoluminescence and Gas Sensor PropertiesThe Journal of Physical Chemistry C, 2009
- The effects of the specific adsorption of anion on the reactivity of the Ru(0001) surface towards CO adsorption and oxidation: in situ FTIRS studiesPhysical Chemistry Chemical Physics, 2008
- Adsorption and Reaction of Ethanol on ZnO NanowiresThe Journal of Physical Chemistry C, 2008
- Size Dependence of Gas Sensitivity of ZnO NanorodsThe Journal of Physical Chemistry C, 2007
- Enhanced Gas Sensing by Individual SnO2 Nanowires and Nanobelts Functionalized with Pd Catalyst ParticlesNano Letters, 2005
- Grain size control and gas sensing properties of ZnO gas sensorSensors and Actuators B: Chemical, 2000
- The influence of chemisorption on the defect equilibrium of metal oxide thin filmsJournal of Applied Physics, 1996
- Thick-film zinc-oxide gas sensor for the control of lean air-to-fuel ratio in domestic combustion systemsSensors and Actuators B: Chemical, 1995
- The reactions of oxygen at dark and irradiated zinc oxide surfacesProceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences, 1960