TM doped CdS Monolayer As Sensing Material toward Harmful Gases of Mines: A first-principles study

Abstract This study evaluated the applicability of TM doped CdS monolayers (TM-CdS, TM=Fe, Co, Ni, Cu) as sensing materials for detecting common harmful gases in mining environments. Using density functional theory, we conducted an in-depth study on the effect of TM doping on CdS monolayers and simulated the adsorption behavior of CO and NO molecules on TM-CdS surfaces. Our research results indicate that TM-CdS exhibits low binding energy, significant charge transfer, and orbital hybridization between TM 3d and S 2p orbitals, confirming their stability. In the adsorption system, due to the small charge transfer amount and high adsorption energy, NO is physically adsorbed on the Cu-CdS system, but exhibits chemical adsorption on CO. In addition, CO and NO molecules adsorbed on Co, Fe, Ni modified CdS belong to chemical adsorption, which is due to the small adsorption distance and energy of the adsorption system, as well as the large charge transfer. At the same time, the results of the conductivity and desorption time of the adsorption system emphasize the potential of TM doped CdS in gas sensing applications, stimulating further research on metal doped CdS materials for detection purposes.