Synthesis and photoluminescence characterization of ZnO nanoparticles

► ZnO precursor was prepared by the precipitation method. ► The ZnO crystallite sizes were increased with increasing the annealing temperature. ► SEM analysis indicated some aggregation due to high surface energy in the products. ► TG-DTA indicates no thermal effect and no further weight loss observed above 450 °C. ► The room temperature PL spectra showed that irrespective of the pH, all products have only a strong UV emission.