Self assembled V2O5 nanorods for gas sensors

Hollow spheres of vanadium pentoxide made up of self assembled nanorods have been prepared successfully by solvothermal method. The calcinated samples of V2O5 nanorods exhibit orthorhombic structure as determined through XRD analysis. The nanorods are found to self assemble into hollow sphere like structures which can be clearly seen in SEM images. The diameter of the hollow spheres were around 2-3 mu m, while the nanorods forming the micro spheres were with diameters in the range of 100-200 nm and are of few hundreds of nanometers in length. The change in the resistance of the V2O5 nanorod sensing element with respect to the test gas concentration was measured by noting down the resistance at each concentration for various time intervals. Sensitivity of the material linearly increased with different concentration of ethanol and ammonia. It is clearly seen that the V2O5 nanorods have more sensing response for ethanol when compared to that of ammonia. (C) 2009 Elsevier B.V. All rights reserved.