A first-principles study on photocatalytic water splitting of XP/SnC (X = B, Ga) heterojunctions

Abstract

In this work, we propose XP/SnC (X = B, Ga) van der Waals heterojunctions as the photocatalyst to split water. The first-principles calculations demonstrate that the BP/SnC heterojunction exhibits a Z-scheme band alignment and the GaP/SnC has a type-II band alignment. Both heterojunctions show the same direction of the build-in electric field. BP/SnC heterojunction fulfills the requirement of photocatalytic water splitting from pH = 0 to pH = 7, whereas the GaP/SnC heterojunction does not. Moreover, applied compressive strain improves the electronic properties of GaP/SnC to achieve photocatalytic water splitting. In addition, both heterojunctions display broad optical absorption spectra and good optical absorption performance. Thus XP/SnC (X = B, Ga) heterojunctions have the potential application in the field of photocatalytic water splitting.