Enhanced plasmonic absorption of Pt cuboctahedra-WO₃ nanohybrids used as visible light photocatalysts for overall water splitting

Localized surface plasmon resonance (LSPR) effects of nanoscale plasmonic metals/semiconductor composites have been extensively applied into visible light photocatalysis. However, Pt nanoparticles (NPs) with the visible LSPR absorption maxima have rarely been used as a photosensitizer to facilitate photocatalytic reactions, especially the photocatalytic overall water splitting (POWS) reaction, presumably because they feature weak light absorption. Herein, we present that the increased plasmonic absorption and local field enhancement can be achieved in the wide visible range by exploiting the simulated and experimental expressions of Pt nanocuboctahedra and Pt cuboctahedra-WO₃ nanohybrids (Pt-WO₃). First, monodisperse Pt cuboctahedra with different sizes, a hierarchical WO₃ nanoarchitecture composed of radially patterned WO₃ nanopillars, and Pt-WO₃ were systematically synthesized. Subsequently, visible plasmonic Pt-WO₃ photocatalysts were employed in the POWS tests and exhibited the significant activity enhancement in the visible light region. The apparent quantum efficiency (AQE) of greater than 7% within the range of visible light has been achieved for the optimal Pt-WO₃.