Ammonia Sensor Based on Monoclinic WO3 Nanorods Operating at Room Temperature

The WO3 nanorods are prepared via the hydrothermal method in our work. The measured indexes were tested and analyzed meticulously to verify the crystal phase is affected due to its calcinated temperature. Furthermore, the scanning electronmicroscope (SEM) and the X-ray diffraction (XRD) are used to characterize the different phaseWO(3). In the light of the results of XRD, the WO3 calcined at 400 degrees C presents hexagonal phase, whereas the WO3 annealed at 500 degrees C and 600 degrees C exhibits monoclinic. On the basis of SEM, the nanorods are gradually disintegrated with the temperature increase. The monoclinicWO(3) demonstrated excellent selectivity to ammonia at room temperature. Moreover, it displayed a short response time and fast recovery rate at optimal working temperature.