Room-temperature hydrogen sensing performance of Nb(2)O(5) nanorod arrays

Nb(2)O(5) nanorod arrays with a hexagonal phase were in situ grown on Nb foil via a facile hydrothermal method. The aspect ratio and spacing of the Nb(2)O(5) nanorods increased upon an increase in the reaction temperature. A pair of platinum electrodes was deposited on the surface of the Nb(2)O(5) nanorod arrays to form a hydrogen sensor. The sensor based on Nb(2)O(5) nanorod arrays exhibited a fast and highly-sensitive hydrogen response with a sensitivity of 74.3% and a response time of 28 s toward 6000 ppm of H(2) at room temperature. The Nb(2)O(5) nanorod arrays also showed good selectivity of H(2) against C(2)H(6)O, CO and NH(3). The hydrogen sensing performance can be attributed to the reaction between chemisorbed oxygen species and H(2). The Nb(2)O(5) nanorods have a high aspect ratio, leading to an increase in the chemisorbed oxygen species on the surface of the [001] orientated nanorods. Moreover, arrays with a vertical structure have low quantities of junctions, which allow oxygen ions to diffuse more easily.