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Journal of Nanomaterials
Volume 2013 (2013), Article ID 389634, 6 pages
http://dx.doi.org/10.1155/2013/389634
Research Article

Synthesis and Surface Characterization of -Mn Nanostructures

Department of Chemical Engineering, Tsinghua University, Beijing 100084, China

Received 29 December 2012; Accepted 19 April 2013

Academic Editor: Yunpeng Yin

Copyright © 2013 Chengxiang Liu et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

A facile method was developed to synthesize γ-MnO2 with different structures and surface properties in this paper. γ-MnO2 was prepared by oxidation of MnSO4 with Na2S2O8 at C for 2.0 h. γ-MnO2 formed at initial pH 1.0 (M1) and 8.5 (M2) was composed of Mn H2O and Mn H2O, respectively. The higher ratio of pyrolusite in M2 ( %) than that in M1 ( %) indicated that compared with M1, M2 would absorb more protons since the planar oxygen atoms in pyrolusite were incompletely coordinated and liable to absorb the protons. Meanwhile, the higher oxidation valence of Mn in M2 than that in M1 revealed that the Mn atoms in M2 were more liable to draw the electron density from the surface oxygen atoms in hydroxyl groups. The structural and compositional differences between M1 and M2 were the major reasons why M2 possessed a higher surface potential and a weaker ability to absorb Zn2+ ions.