Preparation of nanocrystalline zinc carbonate and zinc oxide via solid-state reaction at room temperature

The precursor mixture was obtained by grinding ZnSO4·7H2O and NH4HCO3 with surfactant OP thoroughly at room temperature. Then soluble inorganic salts were removed by washing with water. After drying, the pure nanocrystalline ZnCO3 was obtained. ZnO powder was obtained by one-step thermal decomposition of the ZnCO3 at 400 °C for 1.5 h. Both the ZnCO3 and the ZnO were characterized by TG/DTA, XRD and TEM. The particle size of the ZnCO3 and the ZnO was found to be 50 nm and 20 nm, respectively. The smaller particle size of the ZnO suggests a fact that the crystals of the ZnCO3 play a role in the self-crushing reaction.