Mechanochemical synthesis of silicon carbide using sea beach sand and biomass-derived activated carbon

Abstract A sustainable route for synthesizing silicon carbide was developed using activated carbon derived from Sapindus biomass and naturally sourced silica from sea beach sand. The raw precursors were processed by high-energy ball milling at room temperature, with milling time, ball-to-powder ratio, and rotational speed systematically optimized. The study demonstrated that prolonged milling (24 h) at 380 revolutions per minute with a carbon-to-silicon molar ratio of 1:1 produced well-defined silicon carbide phases. The resulting powders exhibited a uniform microstructure and significant grain size reduction, with crystallite dimensions decreasing to approximately 5 nm. Heat treatment at 1250 °C for 2 h did not markedly alter crystallinity, confirming that mechanochemical activation alone was sufficient to drive carbide formation. These results establish biomass-derived carbon and natural silica as effective precursors for silicon carbide synthesis, offering an eco-friendly and cost-efficient alternative to conventional high-temperature, petroleum-based processes.