Pd-Adsorbing CrS2 monolayer as sensing material for detecting CO, C2H2, and C2H4 in dissolved gases: A first-principles study

This study employs density functional theory to initially examine the adsorption characteristics of Pd atom on CrS₂ monolayer (termed Pd@CrS₂). Subsequently, the adsorption capabilities of Pd@CrS₂ monolayer for CO, C₂H₂, and C₂H₄ are simulated to assess its prospects for dissolved gas detection. Stable adsorption of Pd atoms onto the CrS₂ monolayer atop Cr atoms is observed with a binding energy of −2.69 eV. Pd@CrS₂ exhibits chemisorption towards CO, C₂H₂, and C₂H₄ with respective adsorption energies of −1.49, −1.13, and −1.22 eV. The band structure and density of states analysis indicate significant alterations in the electronic properties of CrS₂ upon Pd adsorption and upon exposure to the gases. The bandgap of Pd@CrS₂ is modified by −29.6 %, −24.7 %, and −27.1 % after CO, C₂H₂, and C₂H₄ adsorption, corresponding to highly sensitive detection responses of −99.6 %, −98.9 %, and −99.3 %. The research highlights the gas sensing capabilities of Pd@CrS₂ monolayers for monitoring the operational status in dissolved gas analysis, showcasing the promising application potential of CrS₂.