| Summary: | 碩士 === 國立臺北科技大學 === 材料科學與工程研究所 === 104 === 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 nanocrystals (IH) 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 of the multiple twinned boundaries of such surfaces. Herein, we demonstrate an one-step strategy for the controlled structural evolution of monodisperse Au-Pd alloy to core-shell IH with ledge-abundant surfaces by tuning the ionic switch between [Br─] and [Cl─] in a co-reduction process. The core-shell IH nanocrystals contain AuPd alloy cores and ultra-thin Pd shells (< 2 nm). They not only display more than double the activity of the commercial Pd catalysts in ethanol electrooxidation attributed to monoatomic step ledges, 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.
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