A localized surface plasmon resonance-interface induces ultrafast hot-electron spatiotemporal transfer for boosting photocatalytic H2 evolution integrated with benzylamine C–N coupling

Abstract

Effective spatiotemporal transfer of electrons/holes is essential for enhancing photocatalytic performance. Plasmonic heterojunction structures can expedite electron transfer to timescales as short as hundreds of femtoseconds. However, the process faces a formidable challenge of hot-electron self-thermalization (100 fs–1 ps), which leads to energy loss of photogenerated carriers. Therefore, it is urgent to develop appropriate catalyst structures for ultrafast electron/hole separation and transfer. Herein, we propose the construction of localized surface plasmon resonance (LSPR)-interface structures that enable ultrafast hot-electron transfer for boosting photocatalysis. Taking MoO_3−x@ZnIn₂S₄ as an example, this plasmonic heterojunction forms an interfacial Mo–S bond with π surface plasmon mode, which can produce a near-field enhancement effect at the interface and suppress the decay of hot-electrons. Then the strong interfacial Mo–S bonding served as a unique channel to enable the ultrafast hot-electron separation and transfer (<100 fs) from MoO_3−x to ZnIn₂S₄. And ultimately the efficient spatiotemporal separation of electrons and holes in MoO_3−x@ZnIn₂S₄ boosted photocatalytic H₂ evolution integrated with benzylamine C–N coupling with the yields of H₂ and C–N coupling products reaching 52.35 and 21.98 mmol g⁻¹ h⁻¹, respectively. Additionally, the apparent quantum efficiencies (AQEs) were as high as 12.56% and 11.26% at 420 nm and 700 nm, respectively. This study not only provides a successful paradigm of constructing a LSPR-interface to realize ultrafast hot-electron direct transfer and spatiotemporal separation for enhancing the overall photocatalytic activity, but also opens a new horizon to design novel photocatalyst structures for cooperative photoredox systems.