Hierarchically nanostructured shuttle-like aragonite mesocrystals: Preparation, characterization, growth mechanism, and removal ability to La(III)

Hierarchically nanostructured Shuttle-like aragonite mesocrystals have been successfully achieved in a water/ethylene glycol (EG) binary solvent system by a facile microwave-assisted method without using any other organic additives. The synthesized products were characterized by a wide range of techniques including X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and nitrogen physisorption analysis. The effects of the ratio of EG to water, and calcium sources on the formation of the special structured aragonite were studied systematically. The results indicate that the cooperation of EG and acetate ions are indispensable to the formation of shuttle-like aragonite mesocrystals, and a plausible oriented attachment formation mechanism is proposed. Moreover, the removal ability of the hierarchical aragonite mesocrystals for La(III) was also tested. Batch experiments reveal that the aragonite possesses excellent removal efficiency to La(III), suggesting that the shuttle-like aragonite mesocrystals can be potentially applied in the removal of rare earth elements (REEs) entering the water environment.

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