Selenium reduction pathways in the colloidal synthesis of CdSe nanoplatelets

Area of Science:

• Nanomaterials Synthesis
• Colloidal Chemistry

Background:

• Established protocols exist for synthesizing zinc blende cadmium selenide (CdSe) nanoplatelets with controlled dimensions.
• The underlying chemical mechanisms governing CdSe nanoplatelet formation remain largely unexplored.

Purpose of the Study:

• To investigate the influence of solvent choice on the synthesis of CdSe nanoplatelets.
• To elucidate the chemical pathways involved in nanoplatelet formation.

Main Methods:

• Synthesis of CdSe nanoplatelets using various solvents and solvent mixtures.
• Analysis using nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS).
• Investigation of alternative reaction pathways involving carboxylic acids and selenium.

Main Results:

• The presence of double bonds in solvents, like 1-octadecene, is crucial for nanoplatelet evolution via alkene isomerization.
• Solvents with α protons adjacent to double bonds can effectively replace 1-octadecene.
• Alternative formation pathways exist, involving carboxylic acids interacting with selenium, even in saturated solvents.

Conclusions:

• Solvent choice significantly impacts CdSe nanoplatelet synthesis.
• Understanding precursor chemistry allows for optimized solvent mixtures to control synthesis and mitigate self-polymerization.
• Alkene isomerization and carboxylic acid-selenium interactions are key chemical processes in CdSe nanoplatelet formation.