Lithium Disilicate (Li2Si2O5): Mild Condition Hydrothermal Synthesis, Characterization and Optical Properties

Lithium disilicate nano-powders were synthesized via a mild condition hydrothermal reaction at 180 ºC for 48 and 72 h with a non stoichiometric1:2 Li:Si molar ratio in NaOH aqueous solution using Li2CO3 and SiO2.H2O as raw materials. The synthesized materials were characterized by powder X-ray diffraction (PXRD) technique and Fourier transform infrared (FTIR) spectroscopy. The XRD data showed that the obtained materials crystallized in a monoclinic crystal structure with a space group of Ccc2. The morphologies of the synthesized nanomaterials were studied by field emission scanning electron microscope (FESEM). Ultraviolet–visible spectra showed that the nanostructured lithium disilicate powders had good light absorption properties in the ultraviolet light region. Photo luminescence spectra of the obtained materials were investigated in an excitation wavelength of 281 nm. Cell parameter refinement data of the obtained materials showed that with increasing the reaction time, parameters a and b were increased. So there is an expansion in the unit cell.