Studies on hydrogen sensing properties of nanostructured Pd and Pd/Mg thin films prepared by pulsed laser deposition

We report on hydrogen sensing studies of palladium and Pd thin film-coated magnesium thin films, which were prepared by pulsed laser deposition. Pd film shows the hydrogenation and dehydrogenation at room temperature leading to a reversible process. While Pd thin film-coated Mg film shows hydrogenation at room temperature and dehydrogenation at 100 degrees C. Electrical resistance measurements were carried out in situ by a two-probe technique in a known pressure of hydrogen gas and air. The change in electrical resistance during hydrogenation/dehydrogenation process is found to be reversible. The film response time is typically 22 s for Pd film and 60 s for Pd thin film-coated Mg film. All films are found to be stable after hydrogenation and dehydrogenation cycle. These studies prove that Pd and Pd thin film-coated Mg thin films also can be used as low-cost and low temperature hydrogen sensor. (C) 2012 Elsevier B.V. All rights reserved.