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ABSTRACT: We fabricated a novel ethanol gas sensor based on organic-inorganic ZnS/cyclohexylamine (CHA) nanowires via a solvothermal route. The sensor exhibited significantly better performance with response time of approximately 0.6 s and recovery time of approximately 10 s even under a low ethanol concentration and the high surface area, small nanofiber diameter, and hybrid nature made the ZnS/CHA nanowire gas sensor have high sensitivity to ethanol gas at a lower operating current of 160 mA. Moreover, the gas sensing mechanism was proposed on the basis of the two simultaneous steps to explain the adsorbing process due to the hybrid nature. This work indicates that the ZnS/CHA hybrid can be a novel candidate for the ethanol gas sensor with high performance.
Journal of Nanoscience and Nanotechnology 03/2011; 11(3):2121-5. · 1.56 Impact Factor
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ABSTRACT: We have successfully fabricated hierarchical ZnSnO3 nanocages via a facile one-pot solution synthesis method. Field emission scanning electron microscopic and transmission electron microscopic results reveal that the cubic ZnSnO3 samples with hollow interior and porous shells are cage-like structure with the side length of 200−400 nm, where the subunits are irregular-shaped nanoparticles. The time-dependent morphology of the ZnSnO3 samples has been investigated, and a possible formation mechanism of these hierarchical structures is proposed. Moreover, gas sensor based on hierarchical ZnSnO3 nanocages exhibits better sensing properties compared with the solid ZnSnO3 nanocubes. The facile preparation method may provide an easy path to the extendable synthesis of other functional nanomaterials with hollow structure and further exploitation of the potential applications.
10/2009;
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ABSTRACT: A simple method for the large-scale synthesis of SnO2 nanofibers has been demonstrated through an electrospinning method. The as-synthesized fibers are characterized by scanning electron microscopy, transmission electron microscopy, selected area electron diffraction, X-ray diffraction, and energy dispersive X-ray analysis. The sensor fabricated from these fibers exhibits high response to toluene at 350 °C with good selectivity. The response time and recovery time are about 1 and 5 s, respectively. The linear dependence of the response value on the toluene concentration is observed in the range of 10–300 ppm. The potential application of SnO2 nanofibers for fabricating high performance toluene sensors at industry level has been demonstrated.
Sensors and Actuators B: Chemical.
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ABSTRACT: Pure and Sm2O3-doped SnO2 are prepared through a sol–gel method and characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The sensor based on 6 wt% Sm2O3-doped SnO2 displays superior response at an operating temperature of 180 °C, and the response magnitude to 1000 ppm C2H2 can reach 63.8, which is 16.8 times larger than that of pure SnO2. This sensor also shows high sensitivity under various humidity conditions. These results make our product be a good candidate in fabricating C2H2 sensors.
Sensors and Actuators B: Chemical.
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ABSTRACT: Pure and KCl-doped TiO2 nanofibers with different crystallographic structures are synthesized by electrospinning and calcination techniques, and their humidity sensing properties are investigated. KCl-doped TiO2 nanofibers with mixed anatase and rutile structures show the highest sensing performance. The impedance of this sample linearly decreases by more than four orders of magnitude with increasing relative humidity from 11% to 95% on a semilogarithmic scale. Both the response time and recovery time are about 3 s. Excellent selectivity, prominent stability, and good reproducibility are also observed based on this sample. The high humidity sensing performance is explained in terms of the ionic contribution of KCl doping and dissociating promotion of mixed crystallographic structure.
Sensors and Actuators B: Chemical.
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ABSTRACT: KCl-doped ZnO nanofibers are synthesized via an electrospinning method and characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The humidity sensing properties of these nanofibers are investigated by screen-printing them on a ceramic substrate with a pair of Ag–Pd interdigitated electrodes. The experimental results show that the 5.7 wt% KCl-doped ZnO nanofibers hold super-rapid response and recovery, high response value, good reproducibility, linearity, selectivity, and stability at 100 Hz. Especially, the response time and recovery time is only about 2 and 1 s, respectively. These results demonstrate the potential application of KCl-doped ZnO nanofibers for fabricating high performance humidity sensors.
Sensors and Actuators B: Chemical.
