Modulation of Z-Scheme Heterojunction Interface between Ultrathin C3N5 Nanosheets and Metal-Organic Framework for Boosting Photocatalysis

Fabricating heterojunction photocatalysts for H-2 production is promising for the development of clean energy. For boosting the photocatalytic activity, modulating the hetero-junction interface can facilitate the electron-hole separation and solar energy utilization, but it is highly challenging in synthesis. In this work, by facilely exfoliating the bulk C3N5, ultrathin C3N5 nanosheets (N-CN) with large surface area, improved light absorption, and efficient charge transport were synthesized and further applied to the construction of NH2-UiO-66/N-CN heterojunctions. The optimized NH2-UiO-66/N-CN-2 exhibits high hydrogen evolution rate and cycling stability with Pt as the cocatalyst. Combined with the experimental results, the density functional theory calculation reveals that the high photocatalytic performance is attributed to the promoted photogenerated carrier transfer by the formation of well-contacted and stable Z-scheme heterojunction interface. This contribution renders an insight into the modulation of the heterojunction interface for enhancing the activity of MOF-based photocatalysts.

Automated summary

This study successfully synthesized ultrathin C3N5 nanosheets with large surface area, improved light absorption, and efficient charge transport, and applied them to construct NH2-UiO-66/N-CN heterojunctions. The optimized heterojunction exhibited high hydrogen evolution rate and cycling stability, attributed to the formation of well-contacted and stable Z-scheme heterojunction interface that promoted photogenerated carrier transfer.