Synthesis of WO3 nanorods by thermal oxidation technique for NO2 gas sensing application

In this work, WO3 nanorods were successfully synthesized by thermal oxidation method and further investigated for gas sensing application. For WO3 nanorods synthesis, tungsten film was deposited on oxidized Si substrate by sputtering method and subsequently subjected to thermal oxidation process at 500 °C in atmospheric environment. The synthesized nanorods were analyzed using SEM, XRD, Raman, and XPS. A chemiresistive type MEMS-based sensing device was fabricated incorporating these nanorods. The sensor was tested for different gases and VOCs over operating temperatures ranging from 75 to 300°C. It showed high selectivity towards NO2 gas over H2S, NH3, acetone, methanol, and ethanol. The excellent sensing performance and sophisticated method of synthesis make this a promising candidate for gas sensing applications.