Decoration of plasmonic Mg nanoparticles by partial galvanic replacement

DOI: 10.1063/1.5131703

Authors: Jérémie Asselin (University of Cambridge) , Christina Boukouvala (University of Cambridge,) , Yuchen Wu (University of Cambridge) , Elizabeth R. Hopper (University of Cambridge) , Sean M. Collins (University of Cambridge) , John S. Biggins (University of Cambridge) , Emilie Ringe (University of Cambridge)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: The Journal Of Chemical Physics , VOL 151

State: Published (Approved)
Published: December 2019
Diamond Proposal Number(s): 21980

Abstract: Plasmonic structures have attracted much interest in science and engineering disciplines, exploring a myriad of potential applications owing to their strong light-matter interactions. Recently, the plasmonic concentration of energy in subwavelength volumes has been used to initiate chemical reactions, for instance by combining plasmonic materials with catalytic metals. In this work, we demonstrate that plasmonic nanoparticles of earth-abundant Mg can undergo galvanic replacement in a nonaqueous solvent to produce decorated structures. This method yields bimetallic architectures where partially oxidized 200–300 nm Mg nanoplates and nanorods support many smaller Au, Ag, Pd, or Fe nanoparticles, with potential for a stepwise process introducing multiple decoration compositions on a single Mg particle. We investigated this mechanism by electron-beam imaging and local composition mapping with energy-dispersive X-ray spectroscopy as well as, at the ensemble level, by inductively coupled plasma mass spectrometry. High-resolution scanning transmission electron microscopy further supported the bimetallic nature of the particles and provided details of the interface geometry, which includes a Mg oxide separation layer between Mg and the other metal. Depending on the composition of the metallic decorations, strong plasmonic optical signals characteristic of plasmon resonances were observed in the bulk with ultraviolet-visible spectrometry and at the single particle level with darkfield scattering. These novel bimetallic and multimetallic designs open up an exciting array of applications where one or multiple plasmonic structures could interact in the near-field of earth-abundant Mg and couple with catalytic nanoparticles for applications in sensing and plasmon-assisted catalysis.

Journal Keywords: Emerging Directions in Plasmonics; Energy dispersive X-ray spectroscopy; Nanomaterials; Plasmonics; Nanoparticle synthesis; Magnesium; Nanoparticles; Transmission electron microscopy

Diamond Keywords: Photocatalysis

Subject Areas: Materials, Chemistry

Diamond Offline Facilities: Electron Physical Sciences Imaging Centre (ePSIC)
Instruments: E02-JEM ARM 300CF

Added On: 07/01/2020 14:13

Discipline Tags:

Physical Chemistry Catalysis Chemistry Materials Science Nanoscience/Nanotechnology

Technical Tags:

Microscopy Electron Microscopy (EM) Transmission Electron Microscopy (TEM) Scanning Transmission Electron Microscopy (STEM)