Rapid and Highly Sensitive Gas Sensing with La-Doped Sno2 Hollow Nanospheres Towards No2 Detection at Room Temperature

The constant challenges associated with metal oxide semiconductor (MOS) gas sensors, such as high operating temperature, low gas-sensing response, and prolonged recovery time towards NO2, demand innovative solutions. In this study, we synthesized La-doped SnO2 hollow nanospheres using a simple one-step hydrothermal method, aided by rapid chip heating. Remarkably, the 3 at% La-doped SnO2 nanospheres treated at 200℃ (referred to as 3LS-200 NSs) exhibited exceptional performance. At room temperature, these nanospheres demonstrated a highly sensitive response of 3008 to 20 ppm NO2 within a rapid response time of 9 seconds. Furthermore, this sensor exhibited a low detection limit of 200 ppb, excellent reproducibility, and long-term stability within 10 weeks. The exceptional gas sensing properties of 3LS-200 NSs towards NO2 can be primarily attributed to the increase of oxygen vacancies through La doping, resulting in a reduced bandgap and enhanced surface electron transfer capability. This work not only presents a simple and energy-efficient strategy for commercial NO2 detection but also holds promise for future advancements in gas sensors.