Hydrogen Sensing with a Single Palladium Nanowire

We describe the properties of single nanocrystalline palladium (Pd) nanowires for the resistancebased detection of hydrogen gas (H2). These Pd nanowires were prepared on glass surfaces using the Lithographically Patterned Nanowire Electrodeposition (LPNE) method. Pd nanowires had a mean grain size of 15 (±3) nm and a height and width in the range from 11 to 48 nm and 36–93 nm, respectively. Sensors consisting of a single Pd nanowire and an evaporated gold electrical contact demonstrated a limit-of-detection for H2 of 2 ppm and withstood repeated exposures to 10% H2 without fracturing. Response and recovery times for nanowires were directly correlated with their lateral dimensions. The reproducibility of the resistance response to H2 and the stability of the resistance baseline were both excellent.