Plasmonic Au nanobipyramid assembly covalent organic framework for boosting photocatalytic hydrogen evolution through strong local electric field

Integrating plasmonic metal nanocrystal/semiconductor hybrids is a novel approach to contribute photocatalyst with high performance. However, a deep insight of activity acceleration remains elusive because of the complex physicochemical behavior of localized surface plasmon resonance (LSPR) effects. Herein, Au nanobipyramids (NBs) capable of strong local electric field (LEF) are precisely synthesized and encapsulated in TpBD-COF via an in-situ growth strategy. As expected, the optimized AuNBs/TpBD-COF hybrid displays a remarkable improvement in photocatalytic H 2 generation reaction, with apparent quantum efficiency (AQE) of 0.58% at 420 nm. Electromagnetic simulation and femtosecond transient absorption spectroscopy demonstrate the critical role of amplified local electric field in generating charge-separated excitons and thus yielding more hot carriers (energetic electron/hole pairs) for H 2 evolution in TpBD-COF. These findings provide a deep insight to examine the LSPR effects for improving the COF-based photocatalytic performance.