Reversible Modulation of Surface Plasmons in Gold Nanoparticles Enabled by Surface Redox Chemistry |
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| Authors: | Dr Zheng Li Dr Jonathan J Foley IV Dr Sheng Peng Dr Cheng‐Jun Sun Dr Yang Ren Dr Gary P Wiederrecht Dr Stephen K Gray Dr Yugang Sun |
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| Institution: | 1. Center for Nanoscale Materials, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (USA);2. X‐ray Science Division, Advanced Photon Source, Argonne National Laboratory (USA) |
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| Abstract: | Switchable surface redox chemistry is demonstrated in gold@iron/iron oxide core–shell nanoparticles with ambient oxidation and plasmon‐mediated reduction to modulate the oxidation state of shell layers. The iron shell can be oxidized to iron oxide through ambient oxidation, leading to an enhancement and red‐shift of the gold surface plasmon resonance (SPR). This enhanced gold SPR can drive reduction of the iron oxide shell under broadband illumination to reversibly blue‐shift and significantly dampen gold SPR absorption. The observed phenomena provide a unique mechanism for controlling the plasmonic properties and surface chemistry of small metal nanoparticles. |
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| Keywords: | core– shell nanoparticles gold nanocrystals iron surface plasmon resonance surface redox chemistry |
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