Abstract: 1-D α-MoO3 nanorods were synthesized under hydrothermal conditions by using (NH4)6Mo7O24·4H2O and HNO3 as raw materials. X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM) were used to characterize phase and morphology of the samples. The width of the α-MoO3 nanorod was about 200-300 nm, and the length was about 5-10 μm. 1-D α-MoO3 nanorods showed good humility sensing properties. The curve of impedance vs. relative humility (RH) changed near five orders of magnitude with good linearity, when RH varied from 11% to 95% at 100 Hz. The response and recovery time of the sensor were about 3 s and 35 s, respectively. The maximum hysteresis was only 4% RH at 100 Hz. In order to explain the conduction process of the sensor, corresponding equivalent circuits were established by complex impedance plots of the device at various humidity ranges. In low RH range, the conduction process was dominated mainly by conduction (charge carriers) and polarization (bounded electrons) of the grains of 1-D α-MoO3 nanorods, while in high RH range, by decomposition and polarization of the absorbed water.
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2017, Vol. 31 
