A direct Z-scheme MoSi<sub>2</sub>N<sub>4</sub>/BlueP vdW heterostructure for photocatalytic overall water splitting
Xuefeng Chen, Wenna Han, Jia Minglei, Fengzhu Ren, Peng Chengxiao, Gu Qinfen, Bing Wang, Yin Huabing
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.