Table 1: Synthesis of MnO2 with different morphologies.

MethodMorphologySizeYear

Molten salt routeNanowires
Nanorods
Length of several microns and diameter of 15–30 nm
Length of 500 nm–2 μm and diameter of 20–40 nm
2009 [10]
Hydrothermal methodUrchin-like nanoballsDiameter of 1 μm2010 [27]
Microemulsion methodNanodisksSize of 1-2 μm and thickness of 50–100 nm2007 [35]
Hydrothermal methodNanotubesOuter diameter of 100 nm, wall thickness of 30 nm, and length of several microns2008 [11]
Hydrothermal methodMultipodsThe legs of the multipods are 200–600 nm in width and several microns in length2006 [36]