Mesoporous TiCrN for trace HS detection with excellent long-term stability.

Efficient, accurate and reliable detection and monitoring of HS is of significance in a wide range of areas: industrial production, medical diagnosis, environmental monitoring, and health screening. However the rapid corrosion of commercial platinum-on-carbon (Pt/C) sensing electrodes in the presence of HS presents a fundamental challenge for fuel cell gas sensors. Herein we report a solution to the issue through the design of a sensing electrode, which is based on Pt supported on mesoporous titanium chromium nitrides (Pt/TiCrN). Its desirable characteristics are due to its high electrochemical stability and strong metal-support interactions. The Pt/TiCrN-based sensors exhibit a much smaller attenuation (1.3%) in response to HS than Pt/C-sensor (40%), after 2 months sensing test. Furthermore, the Pt/TiCrN-based sensors exhibit negligible cross response to other interfering gases compared with hydrogen sulfide. Results of density functional theory calculation also verify the excellent long-term stability and selectivity of the gas sensor. Our work hence points to a new sensing electrode system that offers a combination of high performance and stability for fuel-cell gas sensors.