Carbon Dots as an Electron Acceptor in the ZnIn₂S₄@MIL-88A Heterojunction for Enhanced Visible-Light-Driven...

In this study, visible-light-responsive carbon dots (CDs)/ZnIn₂S₄@MIL-88A (C/ZI@ML) photocatalysts were successfully prepared through in situ loading CDs and ZnIn₂S₄ nanosheets on MIL-88A(Fe) to form a ternary heterojunction. The detailed characterization indicated that the two-dimensional ZnIn₂S₄ nanosheets were uniformly coated on the surface of MIL-88A(Fe), and ZnIn₂S₄/MIL-88A(Fe) exhibited enhanced photocatalytic hydrogen production performance (1259.63 μmol h^-1 g^-1) compared to that of pristine MIL-88A(Fe) and ZnIn₂S₄ under visible light illumination. After introduction of CDs into ZnIn₂S₄/MIL-88A(Fe), the C/ZI@ML catalyst remarkably enhanced the photocatalytic activity and the hydrogen evolution rate of 1C/ZI@ML was up to 3609.23 μmol g^-1 h^-1. The photoinduced charge carriers of C/ZI@ML can be efficiently separated and migrated because of the close contacted interface, synergistic effect, and suitable band structure. In combination with photoelectrochemical experiments and electron paramagnetic resonance spectra, a possible photocatalytic mechanism over C/ZI@ML was proposed. This work demonstrated a facile preparation method for fabricating efficient visible-light-driven heterojunction photocatalysts.