DFT analysis of Re-modified WSe ₂ monolayers for adsorption of CO, C ₂ H ₂ , and C ₂ H ₄

Abstract The sensing performances of the Rhenium (Re) doped Tungsten Diselenide (WSe 2 ) monolayer for detecting small gas molecules such as carbon monoxide (CO), acetylene (C 2 H 2 ), and ethylene (C 2 H 4 ) have been analyzed in this paper. Density functional theory and non-equilibrium Green’s function have been used to examine the electrical and geometric structures of re-adorned WSe 2 monolayer when subjected to dissolved gas analysis gases in the transformer oil. Hence, the electrochemical characteristics like Band diagram and density of states are detailed. Adsorption systems’ recovery capabilities, Mulliken population, and adsorption energy have been examined to determine their stability. Studies also show that Re-doped WSe 2 monolayer exerts deformation and as a result, the band gap narrowed down. At ambient temperature (273 K–300 K), the Re-doped WSe 2 exhibits better adsorption of C 2 H 4 over C 2 H 2 and CO as the C 2 H 4 has higher adsorption energy compared to the C 2 H 2 and CO. Besides, V–I characteristics of the Re doped WSe 2 layer after adsorption of the CO, C 2 H 2 , and C 2 H 4 are detailed which signifies the efficacy of the Re doped WSe 2 monolayer.