Stable Cu sub(2)O nanocrystals grown on functionalized graphene sheets and room temperature H sub(2)S gas sensing with ultrahigh sensitivity

Stable Cu sub(2)O nanocrystals of around 3 nm were uniformly and densely grown on functionalized graphene sheets (FGS), which act as molecular templates instead of surfactants for controlled nucleation; the distribution density of nanocrystals can be easily controlled by FGS with different C/O ratio...

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Bibliographic Details
Published in:Nanoscale 2013-01, Vol.5 (4), p.1564-1569
Main Authors: Zhou, Lisha, Shen, Fangping, Tian, Xike, Wang, Donghong, Zhang, Ting, Chen, Wei
Format: Article
Language:English
Subjects:
AIR POLLUTION
COMPOSITES
COPPER OXIDE
CORROSION
CRYSTAL STRUCTURE
CUPROUS OXIDE
Density
Displays
Graphene
MICROSTRUCTURES
Nanocrystals
Nanostructure
POWER CONSUMPTION
Sensors
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Summary:Stable Cu sub(2)O nanocrystals of around 3 nm were uniformly and densely grown on functionalized graphene sheets (FGS), which act as molecular templates instead of surfactants for controlled nucleation; the distribution density of nanocrystals can be easily controlled by FGS with different C/O ratios. The nanocomposite displays improved stability of the crystalline phase in wet air, which is attributed to finite-size effects that the high-symmetry crystalline phase is to be more stable at smaller size. Meanwhile, we conjecture that the oxygen adsorbed on the interfacial surface prefers to extract electrons from FGS, thus the interfacial bonding also makes a contribution in alleviating the process of corrosion to some extent. More importantly, the Cu sub(2)O-FGS nanocomposite based sensor realizes room temperature sensing to H sub(2)S with fantastic sensitivity (11%); even at the exposed concentration of 5 ppb, the relative resistance changes show good linearity with the logarithm of the concentration. The enhancement of sensitivity is attributed to the synergistic effect of Cu sub(2)O and FGS; on the one hand, surfactant-free capped Cu sub(2)O nanocrystals display higher surface activity to adsorb gas molecules, and on the other hand, FGS acting as conducting network presents greater electron transfer efficiency. These observations show that the Cu sub(2)O-FGS nanocomposite based sensors have potential applications for monitoring air pollution at room temperature with low cost and power consumption.
ISSN:2040-3364
2040-3372
DOI:10.1039/c2nr33164k