OICC Press International Nano Letters 2228-5326 5 2 (June 2015) 2015 02 20 Part III: lithium metasilicate (Li2SiO3)—mild condition hydrothermal synthesis, characterization and optical properties 10.1007/s40089-015-0140-0 EN Abdolali Alemi Department of Inorganic Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, IR Shahin Khademinia Department of Chemistry, Semnan University, Semnan, IR Murat Sertkol Department of Physics Engineering, Istanbul Technical University, Maslak, 34469, TR Journal Article 2015 02 20 Abstract Li 2 SiO 3 nanopowders were synthesized via a non-stoichiometric 2:3 (S 1 ), 1:3 (S 2 ), 1:4 (S 3 ) and 1:5 (S 4 ) Li/Si molar ratios via hydrothermal reaction for 72 h at 180 °C in an aqua solution using Li 2 CO 3 and H 2 SiO 3 as raw materials. The synthesized materials were characterized by powder X-ray diffraction (PXRD) technique and Fourier transform infrared spectroscopy. PXRD data showed that the crystal structure of the obtained materials is orthorhombic with the space group of Cmc2 1 . Also, to investigate the effect of the Li/Si molar ratio on the morphology of the obtained materials, the morphologies of the synthesized materials were studied by field emission scanning electron microscopy. The technique showed that with changing the Li/Si molar ratio from S 1 to S 4 , the morphology of as-prepared samples changed from flower structures to microrod–microsphere and then to a non-homogenous layer-like structure. Ultraviolet–visible spectra showed that the nanostructure lithium silicate powders had good light absorption properties in the ultraviolet light region. It showed that with changing the Li/Si molar ratio from S 1 to S 4 , the calculated band gap was decreased. Also, cell parameter refinement showed that with changing the Li/Si molar ratio from S 1 to S 4 the cell parameters decreased. Photoluminescence analysis of the obtained materials was studied at the excitation wavelength of 247 nm. It showed that the emission spectra of the obtained materials had a blue shift from S 1 to S 4 .