Electronic, magnetic and catalytic of the Janus monolayer transition-metal trichalcogenides

Nowadays, a booming research direction goes toward the newly two-dimensional (2D) layered materials known as metal phosphorus trichalcogenides, which have intrinsic magnetism. Janus 2D materials with mirror asymmetry display novel properties, providing great promise for application in sensors, catalysis, and electronics devices. Herein, the magnetic, electronic as well as the catalytic properties of Janus MPS1.5Se1.5 (M = Mn, Fe, Ni) monolayer trichalcogenides are systematically studied based on the first-principles calculations. We find that all the three Janus MPS1.5Se1.5 possess antiferromagnetic order, however with different antiferromagnetic configurations. Strain-driven magnetic phase transitions are found in FePS1.5Se1.5. Electronic calculations reveal that all the Janus MPS1.5Se1.5 (M = Mn, Fe, Ni) are semiconductors and the band gaps can be tuned by biaxial strain. We further show that the Janus FePS1.5Se1.5 with optima hydrogen adsorption free energy and good conductivity may be potential candidate for HER electrocatalyst.