Synthesis of manganese oxide particles in supercritical water

Abstract

The synthesis of manganese oxide and LiMn2O4 particles in supercritical water has been investigated with a residence time of 10–40 seconds. It was suggested that the reaction temperature for SCW process should be relatively higher than the critical temperature of water, to synthesize the particles of uniform size and shape. It was observed that the selective synthesis of LiMn2O4 was mainly dependent of the amount of OH- ion in the reactants. We concluded that the size, shape and structure of particles were strongly influenced by a change in the reaction temperature, reactant composition and OH- ion amount, and thus enabling to synthesize a specific metal oxide particles. The reaction mechanisms for manganese oxides and LiMn2O4 have been proposed with the oxidation, hydrolysis and dehydration steps.