Plasmon‐Driven C─B Bond Cleavage: Role of Metal Nanobipyramids' Sharpness

Anisotropic metal nanostructures are emerging as groundbreaking photocatalytic platforms by leveraging nanoscale light‐matter interactions, which facilitate unprecedented charge carrier generation and convert photon energy to chemical energy. The present study demonstrates the comparative photocatalytic performance toward the plasmon‐driven protodeboronation reactions by employing gold nanobipyramids (Au NBPs) and silver‐coated gold nanobipyramids (Au@Ag NBPs) as photocatalysts using the molecular fingerprint technique, surface‐enhanced Raman spectroscopy (SERS). With the aid of a plasmonic hotspot, 4‐mercaptophenyl boronic acid (4‐MPBA) was transformed into benzenethiol (BT) under 633 nm laser irradiation. Our investigations revealed that Au NBPs with sharp tips exhibited remarkable catalytic efficiency, achieving a 65% yield within 5 min, whereas Ag‐coated (Au@Ag) NBPs with a small tip curvature radius exhibited enhanced SERS signals with relatively lower yields (44%–55%) and extended reaction times. Surprisingly, Au@Ag NBPs with a large tip curvature radius were found to completely suppress the catalytic activity. Mechanistic pathway was extracted through temperature‐dependent studies (30–90 °C), which indicates that hot charge carriers, rather than photothermal effects, trigger the bond cleavage. This work provides valuable insights into structure–activity relationships in plasmon‐enhanced photocatalysis and establishes Au NBPs as promising candidates for efficient protodeboronation reactions.