Room-temperature hydrogen-selective sensing using single Pt-coated ZnO nanowires at microwatt power levels

Single ZnO nanowires coated with Pt clusters by sputtering are shown to selectively detect hydrogen at room temperature. There were no differences in the current-voltage characteristics for measurement in air, N-2, or vacuum. The single nanowires operate at extremely low power levels of similar to 15-30 mu W, which is approximately a factor of 25 lower than multiple ZnO nanowires operated under the same conditions. The addition of the Pt coatings increased the detection sensitivity of the nanowires for 500 ppm H-2 in N-2 by approximately an order of magnitude, which is about a factor of two improvement over the similar case for multiple nanowires. Pt-coated single ZnO nanowires showed relative responses of similar to 20% and 50%, respectively, after 10 or 20 min exposure, respectively, to 500 ppm H-2 in N-2. (c) 2005 The Electrochemical Society.