Synthesis of Sr₂SiO₄ nanometer particles from the core-shell precursor of SrCO₃/SiO₂

This study presents the formation mechanism for Sr₂SiO₄ synthesized from coated SrCO₃ with gel-derived SiO₂. The experimental results indicate that Sr₂SiO₄ formation from the mechanical mixed precursor with poor mixing homogeneity was dominated by the thermal decomposition of SrCO₃ at higher temperatures. Conversely, the SrCO₃/SiO₂ core-shell precursor can facilitate the formation of Sr₂SiO₄ from the direct reaction between SrCO₃ and SiO₂ at lower calcination temperatures. In addition, raising the coating pH and temperature can promote the shell layer growth that further facilitated Sr₂SiO₄ formation. A nearly pure α-Sr₂SiO₄ product with particle size around 20-50 nm can be obtained at 800 °C for 3 h.