A simple facile approach to large scale synthesis of high specific surface area silicon nanoparticles

An inexpensive, facile, and high throughput synthesis of silicon nanoparticles was achieved by the mechano-chemical reduction reaction of magnesium silicide (Mg2Si) and silicon monoxide (SiO) using a high energy mechanical milling (HEMM) technique followed by acid leaching. Characterization of the resultant product using X-Ray diffraction, Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and surface area analyses was performed at various stages of the synthesis process. XRD patterns show that the final product formed is single phase silicon and the nanocrystalline nature was confirmed by the shifted transverse optical (TO) band, characteristic of nc-Si determined by Raman analysis. SEM and TEM shows the presence of particles of different sizes in the range of few nanometers to agglomerates of few microns which is consistent with products obtained from mechanical milling. BET measurements show a very high specific surface area (SSA) of ~190 m2/g obtained due to acid leaching which is also validated by the porous nature of the particles confirmed by the SEM images.

Schematic showing the large scale production of nanosized silicon and BET surface area of the product formed at various stages.Figure optionsDownload as PowerPoint slide