Nonclassical Pathways: Accelerated Crystal Growth of Sodium Hexafluorosilicate Microrods via Nanoparticle-Assisted...

Nonclassical crystallization represents an innovative pathway that utilizes nanoparticles, enabling the generation of single crystals, going beyond a classical mechanism dependent on atoms, ions, or molecules. Our investigation has revealed hierarchical structures emerging via the aggregation and fusion of primary silicon quantum dots (SiQDs). In contrast to the classical ion-by-ion crystallization process, the primary SiQDs initially undergo aggregation, followed by fusion and their subsequent crystallization, leading to the ultrafast crystal growth of sodium hexafluorosilicate (SHFS) microrods with diverse morphologies. A comprehensive fluorescence microscopy study is performed to examine the mechanism of microrod formation through the primary aggregation and fusion of SiQDs at room temperature in the presence of hydrogen fluoride (HF). The different concentrations of HF play a crucial role in the formation of flower-, block-, and hexagonal-shaped SHFS microrods. However, the presence of a high-concentration HF causes a reduction in microrod size, elucidated through a range of analytical and spectroscopic techniques.