Solvothermal synthesis, characterization and optical properties of ZnO, ZnO-MgO and ZnO-NiO, mixed oxide nanoparticles

ZnO-MgO and ZnO-NiO mixed oxides nanoparticles were produced from a solution containing Zinc acetate, Mg and Ni nitrate by Solvothermal method. The calcination process of the ZnO-MgO and ZnO-NiO composites nanoparticles brought forth polycrystalline two-phase ZnO-MgO and ZnO-NiO nanoparticles of 40-80 nm in diameters. ZnO, MgO and NiO were crystallized into würtzite and rock salt structures, respectively. The optical properties of ZnO-MgO and ZnO-NiO nanoparticles were obtained by solid state UV and solid state florescent. The XRD, SEM and Raman spectroscopies of these nanoparticles were analyzed.

Research highlights► Simple low-temperature hydro/solvothermal method to synthesize of ZnO, ZnO-MgO and ZnO-NiO mixed oxide nanoparticles without any stabilizer or additive studied. ► The crystal quality of the nanoparticles could further be improved through reduction of strain and deep-level defects by annealing them in air. ► Particles size ZnO, ZnO-MgO and ZnO-NiO were controlled by varying the temperature and aging time of the reaction in solvothermal reactor. ► PL spectra results for the ZnO, ZnO-MgO and ZnO-NiO nanoparticles showed significant defects in their morphology due to their large surfaces, while the green emission peak in the nanoparticles was due to a decrease in the amount of excitations. ► The optical properties of these nanoparticles showed a blue-shift of the UV peak for the samples that were placed in the low temperature zone, which occurred due to the effect of Mg and Ni on the band-gap of the ZnO nanostructures.