Controlled synthesis of Mn3O4 nanocrystallites and MnOOH nanorods by a solvothermal method

Mn3O4 nanoparticles and MnOOH nanorods were prepared, respectively, through successfully controlling a solvothermal reaction. An aqueous ethanol solution is used as the solvent. The ethanol volume percent in the solvent and reaction temperature have important effects on the composition of the final products. Experiments show that single phase of Mn3O4 nanoparticles can be prepared at higher reaction temperature and higher volume percent of ethanol (> 50%), while single phase of MnOOH nanorods as single crystallites can be obtained at lower reaction temperature and lower volume percent of ethanol (2-10%). The controlled reactions allow the large-scale and cost-effective synthesis of Mn3O4 and MnOOH with different morphologies, which are expected to show unusual properties and potential applications in catalysis, electrochromic and magnetic materials as well as to afford good precursors for further synthesis and investigation of other manganese oxides. (C) 2004 Elsevier B.V. All rights reserved.