Synthesis, structural and luminescence properties of MgO, Mg₂SiO₄ and MgO/Mg₂SiO₄ nanostructures

Abstract

MgO, Mg₂SiO₄, and MgO/Mg₂SiO₄ nanostructures were synthesized, and their luminescence properties were investigated. The morphological and structural properties of the MgO nanostructures were also characterized. Sponge-like MgO particles with layered nanosheet structures were synthesized by thermally annealing MgCl₂ in air. The MgO nanostructures exhibited a cathodoluminescence emission peak at 5.2 eV with a small peak at 2.4 eV. The Mg₂SiO₄ and MgO/Mg₂SiO₄ nanostructures were also synthesized by annealing MgCl₂ with CaSi₂. Mg₂SiO₄ domains were formed on the surface of the MgO particles. Two main emission peaks were observed for the MgO/Mg₂SiO₄ nanostructures—one at approximately 5.2 eV and another in the range of 2.4–3.4 eV. Compared to MgO, the photoluminescence characteristics of the MgO/Mg₂SiO₄ nanostructures were modified, and the emission peaks were shifted. The formation of Mg₂SiO₄ with MgO expanded the visible–ultraviolet emission regions from 2.4 to 3.4 eV under cathode-ray excitation, followed by a shift from 2.1 to 2.0 eV under photo excitation.