Enhanced hydrogen sensing employing electrodeposited palladium nanowires enclosed in anodized aluminum oxide nanopores

Palladium nanowire sensors have been limited to detecting small concentrations of molecular hydrogen (H₂). Upon excessive hydrogen uptake, tunneling currents fuse the nanowires creating a short circuit causing permanent failure. Here we demonstrate that electrodeposited palladium nanowires enclosed within single-step anodized aluminum oxide nanopores reliably detect hydrogen concentrations greater than four percent and do not suffer the mechanical and electrical failures of conventional self-supporting nanowires. Multiple cycling of molecular hydrogen at 100% concentration and long-term exposure to high concentration of hydrogen does not contribute to permanent short-circuit failure of the sensor.