Promoting Ni(II) Catalysis with Plasmonic Antennas

Plasmonic catalysis has drawn significant interest recently, as the catalysis can be driven by visible light. Here, we show a new tactic to apply low-flux visible-light irradiation on plasmonic metal nanoparticles (NPs) to initiate catalysis with surface-bound transition-metal complexes under mild conditions. Ni2+ complexes (as catalytic reaction sites) and Au or Ag NPs were immobilized on gamma-Al2O3 nanofibers to produce plasmonic-antenna-promoted catalysts. The light irradiation on Au or Ag NPs enhanced photocatalytic activity of the Ni2+ complexes for reductive cleavage of C-O bond by 18-fold or 17-fold, respectively. The intense electromagnetic near-fields of the plasmonic metal NPs significantly increased the chemisorption of the reactant to the Ni2+ active sites. The light-excited hot electrons transfer via a molecular bridge of the aromatic ring of the reactants. The light-enhanced chemisorption plays a key role in this photocatalyst's structure that comprises a plasmonic antenna and catalytically active metal complex sites.