Highly Sensitive Ammonia Sensors Based on Ag-Decorated WO3 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.