Synthesis and field emission property of V2O5•nH2O nanotube arrays

Hydrated vanadium pentoxide (V2O5 center dot nH(2)O) nanotube arrays with outer diameters of 200 nm and lengths of more than 5 mu m have been synthesized via template-based physical wetting of V2O5 sols. The V2O5 center dot nH(2)O nanotube arrays were characterized by scanning electron microscopy, X-ray diffraction, and high-resolution transmission electron microscopy . The field emission (FE) of the V2O5 center dot nH(2)O nanotube arrays shows a turn-on field of about 6.35 V/mu m at a current density of 10 mu A/cm(2) and an emission current density up to 2.1 mA/cm(2) at a field of 9.20 V/mu m. The corresponding Fowler-Nordheim plot shows a linear behavior. These features make the V2O5 center dot nH(2)O nanotube array a promising candidate for FE emitters.