Identification of a critical intermediate in galvanic exchange reactions by single-nanoparticle-resolved kinetics.

نویسندگان

  • Jeremy G Smith
  • Qing Yang
  • Prashant K Jain
چکیده

The realization of common materials transformations in nanocrystalline systems is fostering the development of novel nanostructures and allowing a deep look into the atomistic mechanisms involved. Galvanic corrosion is one such transformation. We studied galvanic replacement within individual metal nanoparticles by using a combination of plasmonic spectroscopy and scanning transmission electron microscopy. Single-nanoparticle reaction trajectories showed that a Ag nanoparticle exposed to Au³⁺ makes an abrupt transition into a nanocage structure. The transition is limited by a critical structural event, which we identified by electron microscopy to comprise the formation of a nanosized void. Trajectories also revealed a surprisingly strong nonlinearity of the reaction kinetics, which we explain by a model involving the critical coalescence of vacancies into a growing void. The critical void size for galvanic exchange to spontaneously proceed was found to be 20 atomic vacancies.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

AgAu bimetallic Janus nanoparticles and their electrocatalytic activity for oxygen reduction in alkaline media.

Bimetallic AgAu Janus nanoparticles were prepared by galvanic exchange reactions of 1-hexanethiolate-passivated silver (AgC6) nanoparticles with gold(I)-mercaptopropanediol complex. The AgC6 nanoparticles were deposited onto a solid substrate surface by the Langmuir-Blodgett method such that the galvanic exchange reactions were limited to the top face of the nanoparticles that was in direct con...

متن کامل

Kinetics of chalcopyrite galvanic leaching using sulfate media at the low temperature in the GalvanoxTM process

In this research work, the dissolution of chalcopyrite was investigated under atmospheric pressure, with sulfate media at low temperatures, in 30°C to 50°C. In the galvanic interaction between chalcopyrite and pyrite, pyrite is used as a leaching catalyst. Effects of different parameters such as temperature, stirring speed, pyrite to chalcopyrite ratio, particle size, and solution potential wer...

متن کامل

Dye Removal from Single and Quaternary Systems Using Surface Modified Nanoparticle: Isotherm and Kinetics

In this paper, dye removal ability of the surface modified nanoparticle SMN copper ferrite from single and quaternary systems was investigated. Acid Blue 92 AB92, Direct Green 6 DG6, Direct Red 23 DR23 and Direct Red 80 DR80 were used as model compounds. The effect of surfactant concentration, adsorbent dosage, dye concentration and pH on dye removal was evaluated. The adsorption isotherm and k...

متن کامل

Numerical Study of Blast Initiation of Detonation Using a Two Step Chemical Kinetics Model

The effect of chemical reactions on the blast initiation of detonation in gaseous media has been investigated in this paper. Analytical method is based on the numerical solution of onedimensional reactive Euler equations. So far, analyses on the blast initiation of detonation have modeled the combustion process as a one-step chemical reaction, which follows the Arrhenius rate law. Previous stud...

متن کامل

C3nr02269b 7284..7289

Trimetallic Ag@AuPt Neapolitan nanoparticles were prepared by two sequential galvanic exchange reactions of 1-hexanethiolate-capped silver nanoparticles (AgC6, 5.70 0.82 nm in diameter) with gold(I)-thiomalic acid (AuTMA) and platinum(II)-hexanethiolate (PtC6) complexes. The first reaction was carried out at the air–water interface by the Langmuir method where the AgC6 nanoparticles formed a co...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Angewandte Chemie

دوره 53 11  شماره 

صفحات  -

تاریخ انتشار 2014