A MoSSe/blue phosphorene vdw heterostructure with energy conversion efficiency of 19.9% for photocatalytic water splitting

We propose a novel van der Waals (vdW) heterostructure composed of MoSSe and blue phosphorene (BlueP) and investigate its structural, electronic, and optical properties by using first-principles calculations. We found that the MoSSe/BlueP vdW heterostructure exhibits robust stabilities, type-II band alignment, suitable band edge positions for water splitting, a large build-in electric field, and strong optical absorption for solar radiation, suggesing the potential of being an ideal photocatalyst for water splitting. Remarkably, it also possesses an excellent power conversion efficiency (PCE) of 12.9%. By applying biaxial tensile strains, this value can be further enhanced: the maximum PCE of 19.9% can be obtained under a 2% tensile strain. Our results are useful for designing high-efficiency photocatalysts for water splitting.