Synthesis and formation process of SrSO₄ sisal-like hierarchical structures at room temperature

Strontium sulfate (SrSO₄) sisal-like hierarchical structures (SLHS) were successfully synthesized by using SrCrO₄ nanowires in mother solution as precursor to react with Na₂SO₄ aqueous solution at room temperature. The SrSO₄ SLHS have a uniform diameter of about 6 μm, which are composed of single-crystalline SrSO₄ nanopyramids oriented radially to their centre. The nanopyramids, which grow along [010] direction, are about 300-500 nm and 20-50 nm for the roots and tips in diameter and 1-3 μm in length. The controlled experimental results indicate that the formation mechanism of the SrSO₄ SLHS is related to the "two-step" growth process.