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

Abstract

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.