Nanostructured Silicon Derived from an Agricultural Residue Bagasse Ash via Magnesiothermic Reduction Method

Abstract

This study presents the magnesiothermic reduction of silica into silicon. This reduction process occurs at a lower reaction temperature than its carbothermal counterpart. Furthermore, silica was extracted from sugarcane bagasse ash via a thermo-chemical treatment method using, for the first time, L-cysteine chloride monohydrate and used as a precursor in the production of silicon using magnesiothermic reduction. The as-synthesized nanocrystalline silicon’s physicochemical properties were investigated using XRD, Raman, FTIR, BET, and SEM. A peak at 2 of 28.2 with a crystallite size of 32 nm was discovered using X-ray diffraction spectroscopy. The pronounced peak around 518 cm−1 was observed from the Raman spectrum, characteristic of crystalline silicon. The FTIR analysis showed two sharp peaks at 446 cm−1 and 1056 cm−1, indicative of the Si-O rocking mode and Si-O-Si stretching mode functional groups present. N2 physisorption at 77 K reveals that the surface area, pore volume, and pore diameter of the as-synthesized silicon were 73 m2/g, 0.23 cm3/g, and 12 nm, respectively. In this study, we were able to produce silicon from silica extracted from SCBA using the magnesiothermic reduction method in a tube furnace, which has potential for thin-film solar cells.