In Situ Electron Microscopy of Plasmon-Mediated Nanocrystal Synthesis

Area of Science:

• Nanotechnology
• Materials Science
• Physical Chemistry

Background:

• Nonthermal energy sources, like visible light, are crucial for advanced energy conversion and synthesis.
• Anisotropic metal nanostructures grown via localized surface plasmon resonance (LSPR) are key examples, but their growth mechanisms and the role of plasmonic hot spots are unclear.

Purpose of the Study:

• To investigate the plasmon-mediated growth mechanism of triangular silver nanoprisms using in situ electron microscopy.
• To understand the influence of plasmonic hot spots on nanostructure growth and chemical reactivity.

Main Methods:

• In situ electron microscopy to stimulate and image the growth of triangular silver nanoprisms in solution.
• Real-time, nanometer-scale quantification of nanoprism size and thickness evolution.
• Correlation of growth rates with local plasmonic field enhancements.

Main Results:

• Observed a transition in silver incorporation from side facets to accelerated thickness growth as nanoprisms enlarge.
• Demonstrated that attachment rates in later stages correlate with plasmonic field enhancements.
• Quantified the effective range of plasmonic hot spots in driving chemical reactions.

Conclusions:

• The study elucidates the growth dynamics of plasmon-mediated nanostructures.
• Findings highlight the critical role of plasmonic hot spots in directing chemical processes.
• Provides a framework for designing efficient nonthermal chemical systems based on plasmonic light harvesting.