am6b12501_si_001.pdf (4.56 MB)
Confined Formation of Ultrathin ZnO Nanorods/Reduced Graphene Oxide Mesoporous Nanocomposites for High-Performance Room-Temperature NO2 Sensors
journal contribution
posted on 2016-12-01, 00:00 authored by Yi Xia, Jing Wang, Jian-Long Xu, Xian Li, Dan Xie, Lan Xiang, Sridhar KomarneniHere we demonstrate
high-performance room-temperature NO2 sensors based on
ultrathin ZnO nanorods/reduced graphene oxide (rGO) mesoporous nanocomposites.
Ultrathin ZnO nanorods were loaded on rGO nanosheets by a facile two-step
additive-free solution synthesis involving anchored seeding followed
by oriented growth. The ZnO nanorod diameters were simply controlled
by the seed diameters associated with the spatial confinement effects
of graphene oxide (GO) nanosheets. Compared to the solely ZnO nanorods
and rGO-based sensors, the optimal sensor based on ultrathin ZnO nanorods/rGO
nanocomposites exhibited higher sensitivity and quicker p-type response
to parts per million level of NO2 at room temperature,
and the sensitivity to 1 ppm of NO2 was 119% with the response
and recovery time being 75 and 132 s. Moreover, the sensor exhibited
full reversibility, excellent selectivity, and a low detection limit
(50 ppb) to NO2 at room temperature. In addition to the
high transport capability of rGO as well as excellent NO2 adsorption ability derived from ultrathin ZnO nanorods and mesoporous
structures, the superior sensing performance of the nanocomposites
was attributed to the synergetic effect of ZnO and rGO, which was
realized by the electron transfer across the ZnO–rGO interfaces
through band energy alignment.