Design of a Dual-Phase TiN-WN electrochemical sensor for HS detection.

Electrode materials are pivotal in fuel cell-based gas sensors, yet conventional Pt-based catalysts often suffer from limitations in electronic structure and stability, restricting the practical application of HS detection. Here, we introduce a Pt catalyst supported by a titanium-tungsten nitride (TiN-WN) composite for an electrochemical HS sensor. Leveraging the multilevel electron transfer of the Pt/TiN-WN composite, this sensor achieves electron accumulation on the Pt surface, yielding enhanced conductivity and abundant active sites for high HS sensitivity. It achieves a response current of 12.2 µA, 1.7 times that of Pt/C (7.1 µA), and demonstrates excellent linearity (R = 0.999), stability over repeated tests, and robust anti-interference capability. These findings mark a significant advancement in HS sensing, offering a reliable solution for real-time monitoring and addressing key limitations of current systems.