Preparation of nanocrystalline Ti, Mn, Co, Fe, and Zn Oxides via heat treatment in aqueous solutions

Abstract

Crystallization, coalescence, chemical reactions, and phase transformations in disperse systems based on hydrous Ti, Mn, Co, Fe, and Zn oxides during heat treatment in solutions of various ionic compositions are analyzed. The results indicate that the transformations in disperse systems follow the dissolution-precipitation mechanism and are accompanied by mass transfer between the solid phase and solution. Reactions are considered, using iron(III) oxyhydroxides as an example, that occur at the solution-crystal interface, and the possible compositions of crystal-forming complexes and the elementary reactions involved in the incorporation of the complexes into different faces of growing crystals of the equilibrium phase are established.