Metastable Plasmonic 4H-Au@Pd Nanoribbons with Plasmon-Enhanced Electrocatalytic Performance for Methanol Oxidation Reaction.

Plasmonic catalysts have drawn great attention due to their ability to enhance catalytic performance by using light as an energy source. To further advance plasmonic catalysis, a fundamental understanding of how intrinsic structural parameters, particularly the crystal phase, govern plasmon-enhanced catalytic behavior remains elusive. In this work, the Au@Pd core/shell nanomaterials with a metastable 4H phase exhibit superior plasmon-enhanced electrochemical performance for the methanol oxidation reaction. Specifically, we synthesized the 4H-Au@Pd nanoribbons (NRBs) using 4H-Au NRBs as templates through epitaxial growth. The mass activity of the 4H-Au@Pd NRBs exhibits a 3.18-fold enhancement, whereas that of the face-centered-cubic Au@Pd nanorods increases by a factor of 1.85. Because of the synergistic effects of the distinct localized surface plasmon resonance properties of the 4H phase, the unique ribbon morphology, and surface properties, the plasmon-enhanced catalytic performance of 4H-Au@Pd NRBs may originate from more efficient separation of photogenerated charge carriers, faster interfacial charge transfer, and a stronger localized heating effect. Our work highlights the potential of metastable nanostructures in plasmonic catalysis and may lead to opportunities for utilization of solar energy.