Electrochemical Pourbaix diagrams of monolayer MoSSe with different atomic ratios of chalcogens

Abstract

MoSSe material is a very promising photoelectric material, and its application environment is aqueous solution. However, there is no research of the electrochemical stability of MoSSe materials in aqueous solution. In this work, the Pourbaix diagrams of monolayer MoSSe with different atomic ratios of molybdenum, sulfur and selenium are constructed based on density functional theory, and the thermodynamic stabilities and electrochemical corrosion behaviors under different pH values and electrode potentials are studied. The study of the pourbaix diagram of MoSSe shows that part of the corrosion-free region of MoSSe exists within the stable region of water in the Pourbaix diagram, indicating that the MoSSe can exist stably in the water environment. Compared with alkaline solutions, MoSSe has good corrosion resistance in acidic solution and neutral solution. The Pourbaix diagram of Mo<sub>4</sub>S<sub>2</sub>Se<sub>6</sub>, Mo<sub>4</sub>S<sub>6</sub>Se<sub>2</sub>, Mo<sub>4</sub>S<sub>7</sub>Se and Mo<sub>4</sub>SSe<sub>7</sub> show that in the case of high molar fraction of sulfur in monolayer MoSSe with different atomic ratios of molybdenum, sulfur and selenium, the conditions for the stable existence of materials in aqueous solution can have a larger range, and the corrosion resistance becomes better. In the case of high molar fractions of selenium in monolayer MoSSe with different atomic ratios of molybdenum, sulfur and selenium, the range of conditions for the stable existence of materials in aqueous solution becomes smaller, and the corrosion resistance becomes worse. In this work, the stabilities and corrosion behaviors of monolayer MoSSe with different atomic ratios of molybdenum, sulfur and selenium in aqueous solution are predicted, and the degradation behaviors of MoSSe materials are further explored, which can provide theoretical guidance for the application of MoSSe materials in the field of optoelectronics.