Synthesis and Field Emission Property of V2O5·nH2O Nanotube Arrays

Hydrated vanadium pentoxide (V 2 O 5 · n H 2 O) nanotube arrays with outer diameters of 200 nm and lengths of more than 5 μm have been synthesized via template-based physical wetting of V 2 O 5 sols. The V 2 O 5 · n H 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 V 2 O 5 · n H 2 O nanotube arrays shows a turn-on field of about 6.35 V/μm at a current density of 10 μA/cm 2 and an emission current density up to 2.1 mA/cm 2 at a field of 9.20 V/μm. The corresponding Fowler−Nordheim plot shows a linear behavior. These features make the V 2 O 5 · n H 2 O nanotube array a promising candidate for FE emitters.