Room-temperature NH3 sensor with ppb detection via AACVD of nanosphere WO3 on IO SnO2

The room temperature gas sensor has attracted sufficient attention due to the fact that low-power products are more suitable for practical environments. However, developing gas sensors with low detection limits remains challenging. In this paper, a room-temperature sensor was prepared by in situ growth of WO 3 nanospheres on SnO 2 inverse opal (IO) by aerosol assisted chemical vapor deposition (AACVD) method, detecting ppb level of ammonia. The WO 3 nanospheres are directly fabricated on IO, and their elemental composition, morphology and structure is characterized using XRD, SEM and TEM. The results show that WO 3 nanospheres have been prepared on SnO 2 IO successfully. It showes that the WO 3 /SnO 2 (WS) type sensor has a detection limit as low as 1 ppb at room temperature from the gas sensitivity data. In addition, the sensor's response value to 100 ppm NH 3 reached 65 %. Its excellent sensing performance depends on the distinctive morphology features of WO 3 and SnO 2 . The hierarchical characteristic effectively enhances the sensing performance for NH 3 . Consequently, this presents a feasible solution for fabricating the room temperature NH 3 sensor.