Synthesis of vanadium oxide nanofibers and tubes using polylactide fibers as template

A new method to produce vanadium oxide nanofibers with dimensions <140 nm and tubes is reported. Vanadium oxide was coated on polylactide fibers by a sol-gel method using a reaction mix of ammonium vanadate and acetic acid as starting materials and water as solvent. Vanadium oxide tubes, of about 1 μm in diameter, were formed when this coated fiber was heated in nitrogen and oxygen at 300 and 250 °C for 1 h. Hydrothermal treatment of the polylactide fibers with the reaction mix at 160 °C for 12 h followed by heating in oxygen at 300 °C for 1 h formed vanadium oxide nanofibers, 60-140 nm in width and several microns in length. Electrochemical studies reveal that these vanadium oxide nanofibers are redox active and readily undergo reversible reactions with lithium in non-aqueous cells.