A direct Z-scheme MoSi₂N₄/BlueP vdW heterostructure for photocatalytic overall water splitting

Abstract

Abstract Building novel van der Waals (vdW) heterostructures is a feasible method to expand material properties and applications. A MoSi 2 N 4 /blue phosphorus (BlueP) heterostructure is designed and investigated as a potential photocatalytic candidate by first-principle calculations. Based on the band alignment and electron transfer, MoSi 2 N 4 /BlueP exhibits the characteristics of direct Z-scheme vdW heterostructure, which is favorable for the spatial separation of photogenerated carriers and retains a strong redox capacity. Moreover, the MoSi 2 N 4 /BlueP possesses suitable band-edge positions for overall water splitting. Compared with the light absorption of two monolayer materials, the heterostructure has a stronger light absorption from the visible to ultraviolet region. The solar to hydrogen conversion efficiency can reach 21.1% for the heterostructure, which is over three-fold and four-fold as great as that of pristine MoSi 2 N 4 and BlueP monolayers, respectively. All the results show that the MoSi 2 N 4 /BlueP heterostructure is a promising photocatalyst for overall water splitting, and it provides new possibilities for designing high-efficiency photocatalysts.