CdS-ZnS Core-Shell Nanoparticle Formation: Experiment, Mechanism, and Simulation

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• 作者：Mani Ethayaraja ; Chettiannan Ravikumar ; Devarajan Muthukumaran ; Kanchan Dutta ; Rajdip Bandyopadhyaya
• 刊名：Journal of Physical Chemistry C
• 出版年：2007
• 出版时间：March 1, 2007
• 年：2007
• 卷：111
• 期：8
• 页码：3246 - 3252
• 全文大小：155K
• 年卷期：v.111,no.8(March 1, 2007)
• ISSN：1932-7455

文摘

CdS-ZnS core-shell nanoparticles are synthesized in a series of water-in-oil microemulsion solutions withincreasing microemulsion drop sizes. Shell formation was confirmed by observation of a red shift in theUV-vis absorption spectra. Nanoparticle diameter and shell thickness estimated independently from the spectraand from mass balance approximation are consistent with each other. A new two-stage mechanism of core-shell nanoparticle formation has been developed from the experimental findings that consists of coalescence-exchange of microemulsion drops with nucleation, growth, and coagulation of particles. Quantitative predictionsfrom Monte Carlo simulation of this mechanism compares well with the temporal evolution of experimentalmean nanoparticle diameter and shell thickness for most of the cases, except when the nature of water in themicroemulsion drops is different from bulk water for very small drop size. An increase in both the core andcore-shell nanoparticle diameter with drop size reflects the control of the microemulsion template structureon nanoparticle synthesis.