MnO2 Nanosheet-Assisted Hydrothermal Synthesis of β-MnO2 Branchy Structures

Branchy structures of beta-MnO2 were prepared through a two-step process including MnO2 nanosheet-assisted hydrothermal synthesis of branchy gamma-MnOOH precursor and followed by calcination of the obtained precursor. After the calcination, the branchy feature was retained for beta-MnO2 with two types of the end structures, i.e., pyramidate ends and opened ends. The assembly and shedding mechanism was proposed to explain the formation of the branchy structure. This nanosheet-assisted hydrothermal method studied here offers a new approach for synthesis of other layered materials. Furthermore, the decolorization experiments of methyl blue (MB) showed that the obtained beta-MnO2 exhibited excellent ability to remove the MB dye with the assistance of hydrogen peroxide. (C) 2012 Elsevier B.V. All rights reserved.