Influence of Microwave Frequency and Power on Nanometal Growth

Autor: Jeffery R. Owens, Bridgett Ashley, Geoffrey F. Strouse, Christopher M. Dyer
Rok vydání: 2018
Předmět:
Zdroj: The Journal of Physical Chemistry C. 122:3617-3627
ISSN: 1932-7455
1932-7447
DOI: 10.1021/acs.jpcc.7b11366
Popis: The rapid heating rates (ΔT/δt) achieved in a microwave (MW) reactor has been shown to accelerate reaction rates due to the direct power absorbed (Pabs) into the reactants leading to faster kinetics. The Pabs is proportional to the dielectric cross section of the materials as defined by the real (e′) and imaginary (e″) components. In a nanocrystal, the dielectric cross-section will be frequency dependent as well as size dependent. In this work, the frequency dependent growth of nickel nanocrystals at frequencies of 2.45, 15.50, and 18.00 GHz at constant ΔT/δt was studied to evaluate the frequency dependence on MW growth of Ni. A scaling law behavior for growth rates is observed that is shown to depend on the MW electric field strength. A relationship is derived between the “configurational energy” of the precursor molecules and the final nanoparticle size. The study provides a clear description of a microwave effect that is dependent on the frequency and power of the microwave and offers further insight i...
Databáze: OpenAIRE