Porous silicon microparticles synthesis by solid flame technique

Porous silicon microparticles have been prepared from SiO2 + αMg (α is mole number of Mg) exothermic mixture by solid flame synthesis method. Two interconnected strategies were followed to initiate morphology changes of as-produced silicon particles, namely changing the concentration of Mg in 0.75–2.0 mol range, and leaching of the combustion products with hydrochloric and/or hydrofluoric acids. The effects of synthesis conditions and chemical treatment procedure on product morphology and composition were evaluated using scanning electron microscopy and X-ray diffraction analysis. Porous silicon microparticles with uniform network structure and pore size distribution ranging from 0.1 to 1.5 μm were prepared after acid treatment of final combustion product. A comprehensive model for pore formation is proposed and discussed in context to the combustion temperature.