Highly Sensitive Ammonia Sensors Based on Ag-Decorated WO 3 Nanorods

In this paper, WO 3 nanorods are successfully synthesized via a one-step hydrothermal method, and then, silver nanoparticles are deposited on the WO 3 surface by in situ photoreduction method to obtain Ag/WO 3 gas sensitive materials. WO 3 and Ag/WO 3 are characterized by scanning electron microscope techniques, transmission electron microscope, and X-ray diffraction. The experimental results indicated that Ag nanoparticles have an important effect on the gas response of WO 3 . The Ag/WO 3 sensor greatly improves the selectivity and response compared to the traditional WO 3 sensor; the response is 300 for 100 ppm ammonia when the Ag/WO 3 sensor operates at the optimum operating temperature. The Ag/WO 3 sensor can respond to 50 ppb ammonia.