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.