Preparation of zinc oxide (ZnO) powders with different types of morphology by a combustion synthesis method

A combustion synthesis process has been established for preparation of ZnO powders with different types of morphologies (that is, agglomerated particles, rod-like structures, and tetrapod whiskers) in air ambience. Metallic zinc and glycine (NH2CH2COOH) powders were used as the fuels, whereas zinc nitrate acted as the oxidant. These reactants were mixed and pressed into a compact. The compact was wrapped up with an igniting agent (i.e., Mg + Fe3O4) and the synthesis reaction was triggered by the combustion of the igniting agent. Both the combustion temperature and the product properties were affected by the reactant composition. A possible reaction mechanism based on thermodynamic calculations and experimental results was proposed that explains the effects of the reactant composition on the combustion reaction.