Investigating the adsorption and sensing of H2S, SO2, NO, and NO2 on transition metal atom doped C7N3 using DFT

This study examines the sensing performance of transition metal doped C₇N₃ sensor structures for four toxic gases (H₂S, SO₂, NO₂, and NO). A series of sensor configurations with single transition metal atoms doped with C₇N₃ (TM-C₇N₃) are constructed. The results of the stability analysis indicate that, with the exception of Ni-C₇N₃, all sensor configurations demonstrate excellent structural stability. Notably, Os-C₇N₃ exhibits a high adsorption strength for four toxic gases. Furthermore, the adsorption strength of TM-C₇N₃ towards NO consistently surpasses that of the other gases investigated. Ultimately, by comparing recovery times, the most effective gas sensor is identified. At 298 K, Pd-C₇N₃ is a suitable H₂S gas sensor, and Fe-C₇N₃ and Co-C₇N₃ are suitable SO₂ gas sensors. At 398 K and above temperatures, Fe- and Rh-C₇N₃ are promising H₂S gas sensors, and Pt-C₇N₃ is a promising SO₂ and NO₂ gas sensor.