Study on the electronic and optical properties of van der Waals heterostructures of blue phosphorene and Janus-WSeS monolayers for photocatalytic water splitting

Abstract

In this paper, we designed a series of heterostructures by assembling the blue phosphorene and Janus-WSeS monolayers together and then selected a stable blue-P/Janus-WSeS van der Waals heterostructure with type-II band arrangement. Further exploration of the band edge shows that it is fit to be the photocatalyst for water splitting. The results from tuning optoelectronic properties via biaxial strain show that the strain is an effective method to adjust the size of the band gap and the band alignment. According to the requirements, a suitable strain can be chosen to adjust the band of the heterostructure. In addition, the absorption coefficient shows a considerable value in the UV region, and the negative strain will enhance the absorption of UV light and weaken the absorption of visible light. Due to the favorable band edge positions and strong absorption in UV light, the blue-P/WSeS heterostructure can be considered as a potential visible and UV light irradiation catalyst for water splitting, and the catalytic activity can be adjusted by strain.