Carrier confinement activated explicit solvent dynamic of CdS/BiVO₄/H₂O and optimized photocatalytic hydrogen...

Herein, using an electrophoretic deposition strategy, a S-scheme CdS (cubic)/BiVO₄ (monoclinic) heterostructured photocatalyst is fabricated. The as-synthesized photocatalysts exhibit high carrier separation efficiency, prominent hydrogen evolution ability and high stability. The results of the detailed density functional theory (DFT) prove that the photogenerated electrons and holes are located in BiVO₄ and CdS components, respectively. Besides, an explicit solvent model based on the electron-enriched region in CdS/BiVO₄ heterojunction is designed deliberately to investigate the solid/liquid interface issues. Intriguing findings demonstrate that the surface hydrogen diffusing rate in CdS/BiVO₄/H₂O is faster than that of BiVO₄/H₂O and is highly associated with the electron-enrich effect, which has a greater capacity to promote water decomposition, the possibility of proton collision and photocatalytic hydrogen evolution. Notably, the H p orbital can participate in the electron-enrich effect during solvation, thus reforming the orbital energy level and activating the HER of the BiVO₄ component in the CdS/BiVO₄ system.