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 (Rair/Rgas = 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.