Bimetallic Phthalocyanine Monolayers as Promising Materials for Toxic HS, SO, and SOF Gas Detection: Insights from DFT Calculations.

The development of a high-performance gas sensor for the rapid and efficient detection of harmful SF decomposition gases (HS, SO, and SOF) is crucial for equipment environmental monitoring and safeguarding human health. In this work, first-principles calculations were conducted to assess the adsorption performance and sensing characteristics of these decomposition gases on two-dimensional metal-dimer-modified phthalocyanine (MnPc, TcPc, and MnTcPc) surfaces. The results demonstrate that the MnPc, TcPc, and MnTcPc monolayers possess enhanced structural stability. The MnPc, TcPc, and MnTcPc monolayer materials show strong adsorption capabilities (|| > 0.90 eV) and significant electron transfer (|| > 0.017 e) and interact favorably with the aforementioned toxic gases, indicating their superior adsorption capacities for SOF, SO, and HS. The microscopic interaction mechanisms between SF-decomposed gas molecules and the MnPc, TcPc, and MnTcPc nanosheets are elucidated through analyses of electron density distribution, differential charge distribution, and density of states. Furthermore, upon absorption of HS, SO, and SOF, the work function and band gap energy of the MnPc, TcPc, and MnTcPc monolayers undergo significant changes, and the magnetic moments of the MnPc, TcPc, and MnTcPc monolayers also exhibit substantial alterations, suggesting high sensitivity to HS, SO, and SOF. Considering the balance of adsorption strength, sensitivity, and recovery time, the single-layer films of MnPc, TcPc, and MnTcPc are deemed to be gas-sensing materials with significant potential, suitable for the development of sustainable gas sensors targeting HS, SO, and SOF with effective recovery capabilities.