Adsorption of small gas molecules on strained monolayer WSe2 doped with Pd, Ag, Au, and Pt: A computational investigation

Abstract Herein, we report on the doping of monolayer WSe2 with Pd, Ag, Au, and Pt as a promising approach to improve the gas sensing performance of the 2D material. The adsorption of CO2, NO2 and SO2 gas molecules on Pd, Ag, Au, and Pt-doped monolayer WSe2 are studied in terms of adsorption energy, charge transfer and band structure. Results suggest that NO2 adsorption on Ag-WSe2 monolayer is energetically favorable giving rise to the most stable configuration. NO2 is chemisorb on the doped monolayer surface due to a strong interaction. We study the influence of applying strain on the gas molecule/TM-WSe2 adsorption systems. Increasing the stain, the adsorption properties decrease for NO2. Our results indicate that Ag-WSe2 monolayer is a great candidate for the development of efficient NO2 gas sensors.