It is important to be able to detect xylene with high selectivity and low sensor resistance when monitoring indoor and outdoor air quality. In this study, we report the development of Sb-doped SnO2 hollow spheres synthesized via ultrasonic spray pyrolysis for high-performance xylene detection with significantly reduced sensor resistance. The 2 mol% Sb-doped SnO2 sensor exhibited a remarkably high response (SX = 24.0) and selectivity (SX/SE = 3.4) toward 5 ppm xylene at 300 °C. Notably, the sensor resistance in air (Ra) was reduced by ~200-fold compared to that of pure SnO2, reaching a practical level of 38.5 kΩ, which enables cost-effective signal measurement. Furthermore, the 2Sb-SnO2 sensor demonstrated a low detection limit of 50 ppb and rapid response times (4–5 s). These results suggest that Sb doping is a highly effective strategy for engineering low-resistance and highly selective SnO2 gas sensors. This study could pave the way for a practical approach to designing xylene detection systems for indoor air monitoring.
Seo et al. (Sat,) studied this question.