A New Solution Route to Hydrogen Terminated Silicon Nanoparticles: Synthesis, Functionalization, and Water Stability.

Hydrogen capped silicon nanoparticles with strong blue photoluminescence were synthesized by the metathesis reaction of sodium silicide, NaSi, with NH4Br. The hydrogen capped Si nanoparticles were further terminated with octyl groups and then coated with a polymer to render them water soluble. The nanoparticles were characterized by TEM, FT-IR, UV-VIS absorption, and photoluminescence. The Si nanoparticles were shown to have an average diameter of 3.9 ±1.3 nm and exhibited room-temperature photoluminescence with a peak maximum at 438 nm with a quantum efficiency of 32% in hexane and 18% in water; the emission was stable in ambient air for up to 2 months. These nanoparticles could hold great potential as a non-heavy element containing quantum dot for applications in biology.