Expanding the scope of antenna–reactor photocatalysts for strong visible light absorption in small transition metal nanoparticles

Abstract

The design of antenna–reactor photocatalysts has become a powerful strategy to covert transition metal reactors from traditional thermocatalysts to novel photocatalysts. Plasmonic metals are often used as the optical antenna. Here, we demonstrate that conventional dielectric supports with high refractive index are able to achieve comparable performance as the plasmonic antennas, giving rise to a huge enhancement of the visible light absorption in the small Pt nanoparticles (NPs) of the core–satellite antenna–reactor photocatalysts through resonance energy transfer. The absorption enhancement can be mediated not only by the electric resonances of the plasmonic antenna but also by the magnetic resonances of the dielectric antenna. A large enough dielectric antenna or a small plasmonic antenna is desired for the generation of strong optical resonances. Judged by those Pt NPs with strong visible light absorption enhancement, the potential catalytically active sites are mainly distributed at the back side of the dielectric antenna, while they may be widely distributed over the surface of the plasmonic antenna with probably lower activities. The expanding scope of antenna–reactor photocatalysts offers new opportunities for solar to chemical energy conversion using nonplasmonic catalytic transition metals.