Interface engineering of GeP/Graphene/BiVO4 heterostructure for photocatalytic Application: A computational study

Abstract

BiVO4 is one of the most promising photocatalyst materials for water splitting due to its band gap and suitable band edge position. However, individual BiVO4 cannot effectively prevent the recombination of photogenerated electron and hole, which leads to poor photocatalytic activity and limits its further application. Matching BiVO4 with a suitable semiconductor is an effective means to improve its photocatalytic activity. In this work, a systematic theoretical research on the optical, charge carrier lifetimes and photocatalytic performance of a novel GeP/BiVO4 and GeP/Graphene/BiVO4 heterostructures have been carried out according to the density functional theory (DFT) and nonadiabatic molecular dynamics (NAMD). Results show that GeP makes a staggered band alignment with BiVO4. The GeP/BiVO4 heterostructure introduces a built-in electric field, but this built-in electric field is not enough to form Z-scheme heterostructure. The graphene intercalation provides a new energy platform and modulates the built-in electric field as well as charge carrier lifetimes, which is highly beneficial to improve the photocatalytic performance for the water splitting. And the reaction free energy shows that GeP/Graphene/BiVO4 heterostructure has the best hydrogen evolution reactions (HER) and oxygen evolution reactions (OER) performance in our calculated structures.