Porous V ₂O ₅ micro/nano-tubes: Synthesis via a CVD route, single-tube-based humidity sensor and improved Li-ion storage properties

Porous V ₂O ₅ micro/nano-tubes were synthesized via a modified chemical vapor deposition process and a possible growth mechanism was proposed. The micro/nano-tubes have large surface area because of their tubular structure with a porous wall. A humidity sensor based on a single porous V ₂O ₅ micro/nano-tube was constructed, and humidity sensing measurements indicated fast response/recovery. Due to the large surface area, the porous V ₂O ₅ micro/nano-tubes were used as a cathode material for lithium-ion batteries that exhibited great improvement of the electrochemical performance such as a high lithium-storage capacity of ∼290 mA h g ^-1, excellent cycling stability and reversibility. Further cyclic voltammetry measurements under different scanning rates confirmed that the intercalation/de-intercalation is of high efficiency and the kinetic performance of the battery is significantly improved. These characteristics of porous V ₂O ₅ micro/nano-tubes make them promising materials for application in gas detection and lithium-ion batteries.