Study on the Properties of the Ferroelectric Photocatalytic Hydrogen Evolution Reaction for Chemically Functionalized Phosphorene Nanosheets

Investigating efficient photocatalysts for the hydrogen evolution reaction (HER) is of paramount importance for advancing renewable energy technologies. Herein, based on the density functional theory calculations, we constructed halogen atom X-intercalated (X = F, Cl, and Br) bilayer phosphorene (BP–X) to achieve efficient HER properties. The results demonstrate that X intercalation can break the inversion of symmetry and generate vertical polarization, which can promote HER properties. In particular, the intercalation of Cl atoms broadens the light absorption peak, reduces the work function, enhances the transition dipole moment, and makes ε P-center move to the Fermi level, thus enhancing the photocatalytic HER properties. Additionally, we have provided a comprehensive explanation of the polarization properties and the underlying reasons for how polarization reversal enhances the HER properties upon Cl intercalation. This study represents a significant advancement in the development of a novel phosphorene-based ferroelectric photocatalyst, which not only enhances the efficiency of HER properties but also sets the stage for the design of 2D ferroelectric photocatalysts.