Ir-doped MoSe2: A promising candidate for C4F7N decomposed species detection and scavenging

Abstract

C4F7N, an environmentally friendly insulating gas, is acknowledged as the foremost promising alternative to SF6. However, C4F7N can decompose upon operational failures or aging of high-voltage electrical equipment, yielding gases with diminished insulating properties and significant toxicity, which severely compromise both equipment operation and personnel safety. Detecting and scavenging C4F7N decomposition species is crucial. Based on density functional theory, this study first proposes Ir-doped MoSe2 (Ir-MoSe2) to investigate its adsorption potential for C4F7N's four primary decomposition species: CF4, C2F6, CF3CN, and CO. Results show that Ir-doping decreases MoSe2’s band gap by 45.21 % and notably enhances its electrical conductivity. Ir-MoSe2 adsorbs CF4 and C2F6 through physical processes, whereas it exhibits strong chemical adsorption for CF3CN and CO. Analyzing the work function, frontier molecular orbitals, and recovery time suggests that Ir-MoSe2 can function as a disposable sensor or a superior adsorbent for CF3CN and CO, even under high-temperature conditions. This study opens new avenues for detecting and scavenging toxic C4F7N decomposition species, significantly enhancing both power system stability and maintenance personnel safety.