Optimization of the Nano-Porous Silicon Structures by Magnesiothermic Reduction of the As-Synthesized Silica

Nano-porous silicon powders were produced via novel efficient magnesiothermic reduction. In this work, thermal and reduction process time effects on the porous silicon structure were investigated. The nano-porous silicon powders were characterized by X-ray diffraction analysis and field emission scanning electron microscopy. It was the first time that the nano-porous structure was produced in presence of both novel SiO_2 cryogel and SiO-2 nano-particles at heating ramp rate of 10 ℃/min and was changed to homogeneous and uniform porous structure throughout the sample when the heating ramp rate was controlled at 5 ℃/min. It was held that the wall thickness and average pore size of uniform porous silicon were decreased from 120.8 nm and 219.05 nm at the heating ramp rate of 10 ℃/min to 87.6 nm and 195.8 nm at heating ramp rate of 5 ℃/min, respectively.