Strong Coupling between Topological Surface States and Localized Surface Plasmonic Resonance in a Dual...

Coupling topological quantum states with localized surface plasmons into a dual antenna-reactor architecture offers an opportunity to transcend the intrinsic limitations of transition metal catalysts, including inadequate light harvesting and insufficient enrichment of energetic electrons. However, the lack of a precise nanoscale integration approach and the limited understanding of interfacial interaction mechanisms hinder its further development. Herein, we describe a sequential assembly strategy to construct a strongly coupled dual antenna (Bi2Se3/Au nanobipyramids)-reactor (Rh) for photocatalytic nitrogen reduction. This architecture enables strong coupling between topological surface states (TSS) and localized surface plasmonic resonance (LSPR), accompanied by directional interfacial electron transfer. Benefiting from such strong coupling, the constructed Bi2Se3/Au dual antenna unit exhibits broadband light-harvesting capability, and the synergistically enhanced localized electromagnetic field further promotes electron enrichment on the Rh nanoparticles. Meanwhile, the Ohmic contact formed at the Bi2Se3/Au interface facilitates the smooth injection of plasmon-induced hot electrons from Au into Bi2Se3 while suppressing the reverse transfer of TSS-excited electrons from Bi2Se3 to Au, enabling unidirectional interfacial electron transfer and effectively improving energetic electron utilization. Consequently, the optimized Bi2Se3/Au-Rh composite achieves a NH3 production rate of 122.7 μmol g-1 h-1 under visible-near-infrared irradiation, which is approximately 23.6, 2.1, and 1.7 times as high as those of pure Rh (antenna-free system), Bi2Se3-Rh (single-antenna system without LSPR), and bulk Bi2Se3/Au-Rh (single-antenna system without TSS), respectively. This work provides a promising strategy for designing topological-plasmonic hybrid photocatalysts toward solar-driven nitrogen fixation.