Morphology-controlled preparation of a-Fe _2O _3 during evaporating aqueous FeCl _3 solution and investigating the electrochemical properties of various a-Fe _2O _3 morphologies

摘要

Morphology-controlled preparation of a-Fe _2O _3 has been successfully realized by evaporating aqueous FeCl _3 solution. By just simply changing the reaction temperature and time, nanorods, peanut-like and sphere-like morphologies, of a-Fe _2O _3 could be obtained. The elemental nanorods have a width range of 10-20 nm. On the basis of time-dependent experiments, the formation mechanisms of various nanostructures were proposed. The dynamic formation process showed that with increasing reaction temperature, the outward bending played critical role on the morphology evolution. Furthermore, when tested as anodes, the as-obtained a-Fe _2O _3 nanostructures showed structure-dependent electrochemical properties. Among them, the a-Fe _2O _3 nanorods exhibited ultrahigh reversible capacity and excellent capacity retention over 50 cycles.