TY - JOUR
T1 - Role of the Exposed Polar Facets in the Performance of Thermally and UV Activated ZnO Nanostructured Gas Sensors
AU - Alenezi, Mohammad R.
AU - Alshammari, Abdullah S.
AU - Jayawardena, K.D.G. Imalka
AU - Beliatis, Michail
AU - Henley, Simon J.
AU - Silva, S.R.P.
N1 - CC-BY
PY - 2013
Y1 - 2013
N2 - ZnO nanostructures with different morphologies (nanowires, nanodisks,
and nanostars) were synthesized hydrothermally. Gas sensing properties of the asgrown
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.
AB - ZnO nanostructures with different morphologies (nanowires, nanodisks,
and nanostars) were synthesized hydrothermally. Gas sensing properties of the asgrown
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.
U2 - 10.1021/jp4061895
DO - 10.1021/jp4061895
M3 - Journal article
C2 - 24009781
VL - 117
SP - 17850−17858
JO - The Journal of Physical Chemistry Part C
JF - The Journal of Physical Chemistry Part C
SN - 1932-7447
ER -