title: Real-Time Plasmonic Monitoring of Single Gold Amalgam Nanoalloy Electrochemical Formation and Stripping.
abstract: Direct electrodeposition of mercury onto gold nanorods on an ITO substrate, without reducing agents, is reported. The growth of single gold amalgam nanoalloy particles and subsequent stripping was monitored in real-time monitoring by plasmonic effects and single-nanoparticle dark-field spectroelectrochemistry techniques. Time-dependent scattering spectral information conferred insight into the growth and stripping mechanism of a single nanoalloy particle. Four critical stages were observed: First, rapid deposition of Hg atoms onto Au nanorods; second, slow diffusion of Hg atoms into Au nanorods; third, prompt stripping of Hg atoms from Au nanorods; fourth, moderate diffusion from the inner core of Au nanorods. Under high Hg(2+) concentrations, homogeneous spherical gold amalgam nanoalloys were obtained. These results demonstrate that the morphology and composition of individual gold amalgam nanoalloys can be precisely regulated electrochemically. Moreover, gold amalgam nanoalloys with intriguing optical properties, such as modulated plasmonic lifetimes and quality factor Q, could be obtained. This may offer opportunities to extend applications in photovoltaic energy conversion and chemical sensing.
authors.affiliation: Key Laboratory for Advanced Materials & Department of Chemistry, East China University of Science and Technology , 130 Meilong Road, Shanghai 200237, P. R. China.
authors.forename: Jun-Gang
authors.initials: JG
authors.lastname: Wang
authors.affiliation: School of Chemistry, University of Birmingham , Edgbaston, Birmingham, West Midlands B15 2TT, U.K.
authors.forename: John S
authors.initials: JS
authors.lastname: Fossey
authors.affiliation: Key Laboratory for Advanced Materials & Department of Chemistry, East China University of Science and Technology , 130 Meilong Road, Shanghai 200237, P. R. China.|State Environmental Protection Key Laboratory of Risk Assessment and Control on Chemical Processes, East China University of Science and Technology , Shanghai 200237, P. R. China.
authors.forename: Meng
authors.initials: M
authors.lastname: Li
authors.affiliation: Key Laboratory for Advanced Materials & Department of Chemistry, East China University of Science and Technology , 130 Meilong Road, Shanghai 200237, P. R. China.
authors.forename: Tao
authors.initials: T
authors.lastname: Xie
authors.affiliation: Key Laboratory for Advanced Materials & Department of Chemistry, East China University of Science and Technology , 130 Meilong Road, Shanghai 200237, P. R. China.
authors.forename: Yi-Tao
authors.initials: YT
authors.lastname: Long
keywords: dark-field spectroelectrochemistry; electrochemical stripping; gold amalgam nanoalloy; plasmon; single nanoparticle