Journal of Materials Research

Articles

Growth of width-controlled nanowires MnO2 from mesoporous carbon and investigation of their properties

Shenmin Zhua1 c1, Xiaolin Wanga2, Wei Huanga3, Deyue Yana3, Honghua Wanga3 and Di Zhanga3

a1 State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200030, People’s Republic of China

a2 Spintronic and Electronic Materials Group, Institute for Superconducting and Electronic Materials, University of Wollongong, New South Wales 2522, Australia

a3 Coll. Chem. & Chem. Eng., State Key Lab Met Matrix Composites, Shanghai Jiao Tong University, Shanghai 200030, People’s Republic of China

Abstract

One-dimensional α-MnO2 nanowires with a controlled width of 10–20 nm have been developed by means of ultrasonic waves from mesoporous carbon using KMnO4 as the precursor. The formation mechanism has been proposed based on the results. A peak around 100 K was detected in the temperature-dependence of magnetization curve, indicating the ferromagnetic state in nanocomposite mesoporous carbon-MnO2, which is in agreement with the transition temperature found from the magnetization versus applied magnetic field curve. The magnetization versus temperature curve of the obtained MnO2 nanowires showed a magnetic transition at about 50 K, illustrating that a parasitic ferromagnetic component is composed on the antiferromagnetic structure of MnO2. The advantage of the method reported here is that phase-controlled synthesis of α-MnO2 nanowires was implemented regardless of pH, temperature, and types of ions in the reaction system. A major advantage of this approach is the efficient, fast, and reproducible control of width and the facile strategy to synthesize nanowires MnO2, in addition to the high purity of the resultant material.

(Received March 16 2006)

(Accepted June 23 2006)

(Online publication March 03 2011)

Key Words:

  • Microstructure;
  • Nanostructure

Correspondence:

c1 Address all correspondence to this author. e-mail: smzhu@sjtu.edu.cn

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