Enhanced hydrogen evolution reaction via photoelectrochemical water splitting utilizing asymmetric MoSSe under a low external magnetic field

Abstract

The co-existence of superior photocatalytic properties and strong spin–orbit-coupling (due to structural inversion asymmetry) in two-dimensional polar MoSSe intensifies the possibility of spin-dependent photo-excited charge transfer for efficient catalysis under an external magnetic field. Herein, a proof-of-concept of the benign role of an external magnetic field in photoelectrochemical water splitting utilizing both spin and catalytic properties of MoSSe is demonstrated. Photocathodes are fabricated by directly growing few layer asymmetric MoSSe on silicon nanowires by a solvothermal method. Delaminated Mo₂CT_x MXene is employed as a cocatalyst. Density functional theory calculations are carried out to comprehend the spin-dependent charge separation mechanism. Due to the synergic effect, the optimized Mo₂CT_x/MoSSe/SiNW photocathode shows a 52% increase in the photocurrent under a 0.4 T magnetic field at zero bias. These findings will offer a fertile ground to cultivate asymmetric two-dimensional materials for a wide range of applications.