A fractionation process of mechanochemically synthesized blue-green luminescent alkyl-passivated silicon nanoparticles

Blue-green luminescent (2.48–3.10 eV) alkyl-passivated silicon nanoparticles (Si NPs) were synthesized in a single step, facile procedure by high energy ball milling single crystal silicon (1 0 0) wafer in the presence of reactive 1-hexyne (C6H10). The subsequent fractionation process allows for the efficient recovery of excess alkyne, purification, and separation of 1-hexyne terminated silicon nanoparticles. This preparative column procedure isolates Si NPs with predominantly nonpolar surfaces as confirmed by FTIR. Samples exhibit photoluminescence emission energies of 2.46 eV for the retained fractions and 2.95 eV for eluted fractions, illustrating a dependence on the polarity of surface passivations.

• Si NPs prepared by reactive high energy ball milling exhibit an array of surface passivations which influence their photoluminescence.
• Fractionation was performed by variation of stationary phases in NPLC system and isolating eluted and retained portion of initial Si NPs sample.
• Retained fractions possess an increase in polar surface passivations compared to eluted fractions which display more alkyl bound species.