Trimethylamine sensing properties of sensors based on MoO3 microrods

MoO3 microrods have been prepared via the probe sonication route using ammonium molybdate, urea and sodium dodecyl sulphate as raw materials. The h-MoO3 phase is transformed to alpha-MoO3 at 400 degrees C. The phase composition and morphology of particles in these materials are characterized through X-ray diffraction (XRD) and transmission electron microscopy (TEM), respectively. The XRD analysis results reveal that h-MoO3 can be obtained at 70 degrees C. TEM images manifest that the average particle sizes are less influenced by the calcination temperature, the particle morphology are rod whose diameters are in the range of 500-750 nm and lengths are about 1-5 mu m. Furthermore, the influence of the heating duration and the heating temperature on the gas-sensing properties of the sensors based on MoO3 microrods is also investigated in this work. The responses to several organic gases, such as (CH3)(3)N and (CH3)(2)CO are studied. It is found that the sensor based on MoO3 nano-material (200 degrees C, 4 h) exhibits best performance in all sensors investigated in this work. The responses of the sensor based on MoO3 (200 degrees C, h) to 1000 and 0.01 ppm (CH3)(3)N at 300 degrees C are as high as 2533 and 1.5, respectively; and the response time and recovery time for 1 ppm trimethylamine are 8 and 9 s, respectively. (C) 2010 Elsevier B.V. All rights reserved.