Facile preparation of single-crystalline nanowires of γMnOOH and βMnO2

A facile method has been developed to synthesize single-crystalline manganese (oxyhydr)oxide nanowires. A pure phase of single-crystalline γMnOOH nanowires with the lengths of several hundred nanometres to several micrometers and the diameters of 5–40 nm was synthesized by hydrothermal transformation of commercial granular γ- or βMnO2 in water, and single-crystalline βMnO2 and polycrystalline αMn2O3 nanowires formed after subsequent calcination at 300 and 600 °C of the as-prepared γMnOOH nanostructures, respectively. These low-dimensional nanostructured materials may find novel properties and provide more possible applications in lithium batteries and catalysis.