Fabrication of 0D/2D Carbon Nitride Quantum Dots/SnNb2O6 Ultrathin Nanosheets with Enhanced Photocatalytic Hydrogen Production

Two-dimensional (2D) nanosheet photocatalysts with appropriate band structure have aroused a great deal of research interest owing to their unique structural and electronic properties. In this work, carbon nitride quantum dots (CNQDs) with up-conversion property were constructed on SnNb2O6 ultrathin nanosheets by a facial hydrothermal process. The as-prepared CNQDs/SnNb2O6 0D/2D nanocomposites exhibited an enhanced photocatalytic performance of H2 production under visible light irradiation (λ > 420 nm). The up-conversion behavior of CNQDs endow the CNQDs/SnNb2O6 nanocomposites with the ability of photocatalytic H2 production at wavelengths greater than 600 nm. Moreover, the introduced CNQDs could serve as effective electron collectors and promote the transfer of photogenerated charge carriers, which is elucidated by the transient photocurrent response and electrochemical impendence spectra. Finally, a plausible photocatalytic mechanism was proposed for CNQDs/SnNb2O6 nanocomposite toward the H2 production from water splitting.