Extraction of high purity Nano-silicon from Quartz Sand by Metallothermic-reduction technique

This study presents an improved approach for extracting high-purity silicon nanoparticles using an enhanced thermal magnesium-aluminum reduction methodology. It lays the foundation for a systematic understanding and transformation of silicon, converting silica (SiO₂) particles into nanosilicon using an optimized aluminum-magnesium mixture for low-temperature silica reduction (a note of low-impact reduction) through a unique chemical treatment. The study employed a protocol of leaching with 4 N HCl followed by treatment with 2.5NNaOH. This was followed by reduction with an aluminum-magnesium mixture, and then a unique chemical treatment involving synergistic leaching and etching of the silicon nanoparticles, along with revitalization etching using a mixture of hydrofluoric and acetic acids. Using this protocol, high-purity silicon nanoparticles with interconnected porous networks were obtained after the complete removal of residual impurities (including methyl green, silicate residues, and other contaminants). Characterization techniques have confirmed the integrated nature of the structure and form of the extracted silicon. All the products were characterized using a field emission scanning electron microscope (FE-SEM), energy dispersive spectroscopy (EDS/EDX), and x-ray diffraction (XRD). The results showed that nanosilicon production had an average diameter of 49.8625 nm, 30.155, and 58.635 nm when extracted from S1, S2, and S3. Also, the XRD and FT-IR results confirm the high purity of the produced nanosilicon nanoparticles. Despite current challenges associated with producing large quantities of porous silicon nanomaterials using MTR technology, the modified thermochemical method offers a scalable, low-cost, high-throughput approach to manufacturing advanced silicon-based nanomaterials.