Hierarchical mesoporous SrCO₃ submicron spheres derived from reaction-limited aggregation induced “rod-to-dumbbell-to-sphere” self-assembly

Hierarchical mesoporous SrCO₃ submicron spheres were fabricated via a facile and direct hydrothermal method. This was realized via the room temperature co-precipitation of Na₂CO₃ and SrCl₂ solution in presence of appropriate amount of MgCl₂ and ethylene diamine tetraacetic acid disodium salt, which led to bouquet-like SrCO₃ nanostructures at first. Then the precipitate was hydrothermally treated at 190 °C for 12.0 h, resulting in uniform hierarchical SrCO₃ submicron spheres. The characterization results definitely determined the hierarchical SrCO₃ submicron spheres of mesoporous structure, bearing a specific surface area of 40.2 m² g⁻¹, a total pore volume of 0.145 cm³ g⁻¹, and a narrow pore size distribution concentrating on 3–20 nm with an average pore diameter of 14.4 nm. Finally, the reaction-limited aggregation induced “rod-to-dumbbell-to-sphere” mechanism was proposed to explain the formation of the hierarchical mesoporous submicron spheres.