Two-dimensional blue phosphorene–BAs vdW heterostructure with optical and photocatalytic properties: a first-principles study

Constructing van der Waals (vdW) heterostructures is an exciting method for tuning the electronic and optical properties and the photocatalytic performances of two-dimensional materials. In this work, we investigated the electronic, optical and photocatalytic properties of a blue phosphorene–BAs (BlueP–BAs) vdW heterostructure using first-principles calculations. We found that the most energetically favorable stacking pattern of the BAs–BlueP vdW heterostructure possesses a direct band gap with type-I band alignment. The absorption spectrum of the BAs–BlueP vdW heterostructure showed that the lower energy transitions are dominated by excitons. Furthermore, the photocatalytic performance of the BAs–BlueP vdW heterostructure makes it suitable for water splitting at pH = 0. Our findings demonstrated that the BlueP–BAs heterostructure is a good candidate for optoelectronic and photocatalytic devices.