Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
744964 | Sensors and Actuators B: Chemical | 2006 | 5 Pages |
Nanoporous Pd films supported by porous anodic aluminum oxides (AAOs) were investigated regarding their performance in detecting hydrogen gas with concentrations up to 1% in nitrogen at room temperature. Compared with dense Pd films that usually have very slow responses, nanoporous Pd films based on AAOs were found to have a quick and reversible response due to their enhanced absorption and disorption of hydrogen. Using thinner nanoporous films, concentrations of hydrogen as low as 250 ppm can be detected and a much higher sensitivity, up to 12% resistance variation, was obtained. Two competing hydrogen-sensing processes, the phase-induced increase of film resistance and the break-junction-induced decrease of film resistance, were found in the nanoporous Pd films upon absorption of hydrogen.