A fuel cell type gas sensor based on Pt/NbN for highly selective detection of hydrogen sulfide

• The selectivity of Pt/NbN based sensor is significantly improved compared with Pt/C. • Mesoporous NbN as a support material is conducive to the long-term stability of the sensor. • The ppb-level LoD (limit of detection) for H 2 S exhibits the potential of monitoring trace pollutants. Hydrogen sulfide (H 2 S) is considered a highly hazardous toxic gas. H 2 S sensors are therefore of paramount significance for real-time leak detection. However, existing solutions do not meet the strict performance targets set by stakeholders, while deactivation due to surface area of sensing materials decrease and contamination is a widely unsolved problem. Presented here is a new support material, mesoporous niobium nitride (NbN), which improve the long-term stability largely via enhancing the interaction between metal and support. Simultaneously, sensor devices using NbN as support show enlarged sensitivity, enhanced limit of detection and well repeatability when compared with these sensors using traditional carbon black support. In a wider perspective, our work suggests strategies for enhancing long-stability of next-generation chemical gas sensors by optimizing metal-support interaction.