Molten bismuth process forms nanoporous silicon carbide at lower temperature
A Tohoku University team used liquid metal dealloying to produce crystalline beta silicon carbide at 800°C, much lower than typical synthesis temperatures. The method immersed a layered manganese-silicon-carbide precursor in molten bismuth, which removed manganese and left a three-dimensional network of nanoscale plates. First-principles calculations supported the feasibility of the structural rearrangement.
Researchers at Tohoku University’s Institute for Materials Research produced crystalline beta silicon carbide at 800°C by immersing a layered Mn5SiC compound in molten bismuth. The bismuth drew manganese out of the solid, leaving a silicon-carbon skeleton that rearranged into a 3D web of linked nanoplates. First-principles calculations indicated the rearrangement had a favorable energy balance.
Silicon carbide is valued for resisting heat and chemical attack, making it useful for electronics, catalysis, and energy technologies. Yet conventional routes often need high temperatures, and creating nanoscale porosity while forming the ceramic is difficult. The team’s approach extends liquid metal dealloying—previously applied mostly to metals, intermetallics, and semimetals—to a strongly covalent ceramic, as reported in Scripta Materialia.
If scaled, this lower-temperature route may reduce energy demands for producing nanoporous silicon carbide, potentially benefiting manufacturers of electronics, catalysts, and energy devices. Researchers and materials engineers could gain a milder way to tune ceramic porosity, though industrial adoption would depend on cost, scalability, and reproducibility. Consumers might see indirect effects through more efficient or durable components, but near-term impact is likely confined to laboratory and specialty materials development.