Photocatalytic Water Oxidation Directly Using Plasmonics from Single Au Nanowires without the Contact with Semiconductors

Plasmon-induced photocatalytic reactions are important in the process of conversion of solar energy into fuels. To efficiently harvest energetic charge carriers from light-excited plasmonic materials, contact of the metallic nanostructures with semiconductors is necessary. Herein, we report that, even on single Au nanowires that are not in contact with any semiconductors, prominent photocatalytic water oxidation reactions could be still observed. The involved Au nanowires have dimensions of 300 nm in diameter, and the fabricated nanoelectrode presents an obvious photocurrent of 0.4 mA/cm2 at the potential of 1.2 V vs Ag/AgCl. The corresponding incident photon-to-electron conversion efficiency is realized as 0.24% at the wavelength of 520 nm. Detailed investigations reveal that the hot holes around the d-band of the plasmonic nanomaterials are responsible for such photocatalytic behaviors. Our results provide a special perspective to the plasmon-related reactions.