Synthesis, Characterization, and Gas Sensing Applications of WO₃ Nanobricks

WO₃ nanobricks are fabricated by a simple hydrothermal method. Morphology and structure of the WO₃ nanobricks are characterized by scanning electron microscopy and x-ray diffraction. Gas sensing properties of the as-prepared WO₃ sensor are systematically investigated by a static gas sensing system. The results show that the WO₃ nanobricks with defect corners demonstrate good crystallinity, and the mean edge length and wall thickness are 1-1.5 and 400 nm, respectively. The WO₃ sensor achieves its maximum sensitivity to 100 ppm ethanol at the optimal operating temperature of 300 °C. Ultra-fast response time (2-3 s) and fast recovery time (4-11 s) of the WO₃ sensor toward 100 ppm ethanol are also observed at this optimal operating temperature. Moreover, the WO₃ sensor exhibits high selectivity to other gases such as methanol, benzene, hexane, and dichloromethane, indicating its excellent potential application as a gas sensor for ethanol detection.