Theoretical design of InSe/GaTe VDW heterobilayer: A potential visible-light photocatalyst for water splitting

摘要： Using first-principles calculations, we show that two-dimensional (2D) van der Waals (vdW) InSe/GaTe heterobilayer (HBL) can serve as a potential visible-light-driven photocatalyst for water splitting to produce hydrogen, which notably improves the photocatalytic performance over isolated InSe and GaTe monolayers. The type-II band alignment and high carrier mobility of the InSe/GaTe HBL facilitate the spatial separation of photo-generated carriers and thus enhances the photocatalytic efficiency. Meanwhile, the separated absorption of H+ and OH- on the surfaces of InSe/GaTe HBL is beneficial to the photocatalytic redox reactions. Moreover, InSe/GaTe HBL can significantly extend the range of light harvesting from visible-light to infrared-light. The predicted maximum power conversion efficiency (PCE) attains 12.3%. These results indicate the InSe/GaTe HBL is a promising photocatalyst for water splitting.