Carbon Dots as an Electron Acceptor in the ZnIn 2 S 4 @MIL-88A Heterojunction for Enhanced Visible-Light-Driven Photocatalytic Hydrogen Evolution.

In this study, visible-light-responsive carbon dots (CDs)/ZnIn 2 S 4 @MIL-88A (C/ZI@ML) photocatalysts were successfully prepared through in situ loading CDs and ZnIn 2 S 4 nanosheets on MIL-88A(Fe) to form a ternary heterojunction. The detailed characterization indicated that the two-dimensional ZnIn 2 S 4 nanosheets were uniformly coated on the surface of MIL-88A(Fe), and ZnIn 2 S 4 /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 ZnIn 2 S 4 under visible light illumination. After introduction of CDs into ZnIn 2 S 4 /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.