Atomic Ru Species Driven SnO₂-Based Sensor for Highly Sensitive and Selective Detection of H₂S in the ppb-Level

Timely and accurate detection of H₂S is crucial for preventing serious health issues in both humans and livestock upon exposure. However, metal-oxide-based H₂S sensors often suffer from mediocre sensitivity, poor selectivity, or long response/recovery time. Here, an atomic Ru species-driven SnO₂-based sensor is fabricated to realize highly sensitive and selective detection of H₂S at the parts per billion level as low as 100 ppb. The sensor shows a high sensing response (R_air/R_gas = 310.1) and an ultrafast response time (less than 1 s) to 20 ppm H₂S at an operating temperature of 160 °C. Operando SR-FTIR spectroscopic characterizations and DFT calculations prove that the superior sensing properties can be mainly attributed to the driven effect of atomic Ru species on the formation of surface-adsorbed oxygen species on the surface of SnO₂, which provides more active sites and enhances the sensing performance of SnO₂ for H₂S. Furthermore, a lab-made wireless portable H₂S monitoring system is developed to rapidly detect the H₂S for early warning, suggesting the potential application of the fabricated H₂S sensor and monitoring system. This work provides a novel approach for fabricating a highly sensitive and selective gas sensor driven by atomic metal species loaded on metal-oxide semiconductors.