Core–Shell–Satellite Plasmonic Photocatalyst for Broad-Spectrum Photocatalytic Water Splitting

Photocatalytic water splitting is an ideal way of generating hydrogen, a renewable energy source, from solar energy that would help solve environmental problems. However, current photocatalysts are far from meeting performance requirements for commercial applications. Recently, increasing attention has been paid to surface plasmon resonance (SPR) enhanced photocatalysis using plasmonic nanoparticles (NPs) because of their superior solar energy harvesting capabilities in the visible and near-infrared spectral region. Herein, based on the common CdS photocatalyst, a series of core–shell plasmonic photocatalysts with different core types and shell layer thicknesses were constructed. By combining experimental results and finite element method (FEM), the near-field enhancement mechanism and plasmon-induced resonance energy transfer mechanism was derived. To further improve the energy conversion efficiency, a core–shell–satellite-type plasmonic nanocomposite photocatalyst, Ag@SiO2@CdS-Au, was designed and constructed. Because of hot electron injection and plasmonic coupling effects, the light absorption of the photocatalyst was effectively expanded, which significantly improved the catalytic performance. Compared with traditional CdS, the photocatalytic performance of the plasmonic nanocomposite photocatalyst was improved by more than 200 times. This work deepens the understanding of the mechanisms in SPR enhanced photocatalysis and provides an effective strategy for designing plasmonic photocatalysts.