The Impact of Secondary Building Units in Metal-Organic Frameworks on Plasmonic Gold-Sensitized Photocatalysis

Embedding plasmonic metals in metal-organic frameworks (MOFs) can build an advanced visible-light photocatalyst architecture utilizing the localized surface plasmon resonance (LSPR) effect, while the practical performances have been restricted by the sluggish charge transfer at metal-MOF interface and through the secondary building units (SBUs) of the adopted carboxylate MOFs currently. Herein, a pyrazolate Ni-MOF (PFC-9) featured with an 1D SBU chain is selected to be the host catalyst to immobilize Au nanoparticles as a novel and optimized construction for LSPR photocatalysis. Compared with the common 3D-connected SBUs of carboxyl-ZrOx and pyrazole-NiOx configurations in the reference MOFs, the 1D (-Ni-N-Pz-N-Pz-)(infinity) chain in PFC-9 creates abundant Au/MOF contacts, a short and low-resistant pathway for Au-to-Ni2+ transport of hot electrons, and enables fluent electron utilization at the continuous active Ni sites. Consequently, the Au/PFC-9 photocatalyst achieves the optimum activity for visible-light-driven H-2 production. This work shows an example to promote the LSPR-sensitized photocatalysis taking the advantage of MOFs' structural tunability, providing significant guidance for the rational design of highly efficient photocatalysts.

Automated summary

This study demonstrates the construction of an advanced visible-light photocatalyst architecture by embedding plasmonic metals in metal-organic frameworks. The optimized catalyst achieved the best activity for visible-light-driven hydrogen production. This research provides significant guidance for the rational design of highly efficient photocatalysts.