Theoretical Comparison Between Noble Metal (Pd or Ru)-Doped GeS2 Monolayers as Sensitive Materials upon C4F7N Decomposed Gases

This work comparably investigates the gas sensing potential of noble metal (Pd and Ru)-doped GeS2 monolayers upon three C4F7N decomposed species (FCN, CF3CN, and C2F4) using the first-principles theory, for operation status evaluation in C4F7N-insulated devices. The Pd- and Ru-doping effects on the pristine GeS2 monolayer are analyzed, followed by the adsorption mechanism and sensing performance of two doped monolayers. Our results demonstrate that while Ru doping induces stronger surface interactions with the GeS2 substrate and consequently exhibits superior adsorption strengths upon the three gases, the Pd-doped monolayer shows remarkable advantages in charge transfer capability that leads to exceptional room-temperature sensitivity responses of −99.6% (FCN), −95.0% (CF3CN), and −88.0% (C2F4), thus significantly outperforming the Ru-doped system. Combined with the instantaneous recovery for gas desorption, the Pd-GeS2 monolayer holds significance as an ideal room-temperature sensor to monitor the operation status of C4F7N-insulated devices in power systems. This research provides promising insights into the application of GeS2-based materials for gas sensing in power systems and emphasizes the importance of dopant selection in designing high-performance gas sensing materials, especially for developing advanced electrical equipment monitoring technologies.