Plasmonic Bi/COF Nanoheterojunction for Enhanced Artificial Photosynthetic CO₂ Reduction

Surface plasmon resonance (SPR) represents an ideal strategy for boosting photocatalytic activity via synergistic effects of plasmon-induced electron transfer and resonant energy conversion. Herein, we present a strategy that integrates bismuth metal nanoparticles (Bi NPs) with covalent organic framework nanosheets (COF-NS) to develop a stable Bi-based plasmonic photocatalyst for the artificial photocatalytic reduction of carbon dioxide (CO₂RR) and verify its advantages over the pristine TpBpy-COF NS. As a result, the Bi NPs/COF-NS nanoheterojunction shows a prominent enhancement of light absorption and facilitates the separation of photogenerated charges, which can be ascribed to the surface plasmon resonance effect within the system. This strategy achieves a prominent visible-light-driven carbon dioxide to a carbon monoxide conversion rate of 217 μmol·g^-1·h^-1 under a pristine CO₂ atmosphere, which is 12.2-fold higher than that of the parent COF. This study not only demonstrates a bismuth-based plasmonic photocatalyst with exceptional catalytic activity but also establishes a feasible design strategy to construct plasma photocatalysts for CO₂ reduction.