title: Turning the Halide Switch in the Synthesis of Au-Pd Alloy and Core-Shell Nanoicosahedra with Terraced Shells: Performance in Electrochemical and Plasmon-Enhanced Catalysis.
abstract: Au-Pd nanocrystals are an intriguing system to study the integrated functions of localized surface plasmon resonance (LSPR) and heterogeneous catalysis. Gold is both durable and can harness incident light energy to enhance the catalytic activity of another metal, such as Pd, via the SPR effect in bimetallic nanocrystals. Despite the superior catalytic performance of icosahedral (IH) nanocrystals compared to alternate morphologies, the controlled synthesis of alloy and core-shell IH is still greatly challenged by the disparate reduction rates of metal precursors and lack of continuous epigrowth on multiply twinned boundaries of such surfaces. Herein, we demonstrate a one-step strategy for the controlled growth of monodisperse Au-Pd alloy and core-shell IH with terraced shells by turning an ionic switch between [Br(-)]/[Cl(-)] in the coreduction process. The core-shell IH nanocrystals contain AuPd alloy cores and ultrathin Pd shells (<2 nm). They not only display more than double the activity of the commercial Pd catalysts in ethanol electrooxidation attributed to monatomic step terraces but also show SPR-enhanced conversion of 4-nitrophenol. This strategy holds promise toward the development of alternate bimetallic IH nanocrystals for electrochemical and plasmon-enhanced catalysis.
authors: Institute of Chemistry, Academia Sinica , Taipei 11529, Taiwan.|Department of Materials and Mineral Resources Engineering, National Taipei University of Technology , Taipei 10608, Taiwan.
authors: Shih-Cheng
authors: SC
authors: Hsu
authors: National Synchrotron Radiation Research Center , Hsinchu 30076, Taiwan.
authors: Yu-Chun
authors: YC
authors: Chuang
authors: Brian T
authors: BT
authors: Sneed
authors: David A
authors: DA
authors: Cullen
authors: Department of Materials and Mineral Resources Engineering, National Taipei University of Technology , Taipei 10608, Taiwan.
authors: Te-Wei
authors: TW
authors: Chiu
authors: Institute of Chemistry, Academia Sinica , Taipei 11529, Taiwan.
authors: Chun-Hong
authors: CH
authors: Kuo
keywords: Gold; catalysis; icosahedral; nanocrystal; palladium