CO₂ utilization for fast preparation of nanocrystalline hydrozincite

In this study, gaseous CO₂, solid ZnO and liquid H₂O were converted to nanocrystalline (13 nm) hydrozincite, i.e. Zn₅(CO₃)₂(OH)₆ via fast one-step mechanochemical process at ambient temperature and pressure. The mechanically induced conversion of the three-phase mixture, studied by X-ray diffraction analysis, Fourier-transform infrared and X-ray photoelectron spectroscopies, completed in 10 min. X-ray diffraction and Fourier-transform infrared spectroscopy indicated the presence of disorder in the crystal structure of mechanosynthesized hydrozincite The physico-chemical properties of the mechanosynthesized hydrozincite, characterized in the view of surface and optical properties, were compared with the commercial hydrozincite. It was found that the Brunauer-Emmett-Teller surface area was almost 2 times higher (56.7 m²/g) than the corresponding value of the commercial material, which is related to the smaller particle size (∼230 nm). Both the ultraviolet-visible absorption and photoluminescence emission spectra recorded for the mechanosynthesized hydrozincite indicated size effect. The weight loss (26.5%) obtained during thermal decomposition of the mechanosynthesized material is close to the theoretical weight loss value of hydrozincite.