Hydrogen Sensors and Switches from Electrodeposited Palladium Mesowire Arrays
Frédéric Favier,1
Erich C. Walter,2
Michael P. Zach,2
Thorsten Benter,2
Reginald M. Penner2*
Hydrogen sensors and hydrogen-activated switches were
fabricated from arrays of mesoscopic palladium wires. These palladium "mesowire" arrays were prepared by electrodeposition onto graphite surfaces and were transferred onto a cyanoacrylate film. Exposure to
hydrogen gas caused a rapid (less than 75 milliseconds) reversible decrease in the resistance of the array that correlated with the hydrogen concentration over a range from 2 to 10%. The sensor response
appears to involve the closing of nanoscopic gaps or "break
junctions" in wires caused by the dilation of palladium grains
undergoing hydrogen absorption. Wire arrays in which all wires
possessed nanoscopic gaps reverted to open circuits in the absence of
hydrogen gas.
1 UMR 5072 CNRS-Université
Montpellier II, 34095 Montpellier, France.
2 Department of Chemistry, University of California
Irvine, Irvine, CA 92697-2025, USA.
*
To whom correspondence should be addressed. E-mail:
rmpenner{at}uci.edu
