Investigators: J.E. Indacochea , M.L. Wang, Department of Civil and Materials Engineering, UIC

1. AAO nanowell Pd nanoparticle Al substrate H off H on Change in resistance in presence of hydrogen at different concentrations Development of Ultrafast AAO Nanowell/Pd Nanoparticle Structures for Hydrogen Detection at Low Temperature Investigators: J.E. Indacochea, M.L. Wang, Department of Civil and Materials Engineering, UIC H.H. Wang, Materials Science Division, Argonne National Laboratory Primary Grant Support: National Science Foundation • Hydrogen has been envisioned as a futuristic energy system. Gas detectors will be key components to ensure safety and reliability in hydrogen infrastructure. • Limitations of current hydrogen sensing devices include long response time, low sensitivity, and poor performance at room temperature. • Very large active surface and nanoscale dimensions make nanostructures a promising alternative to overcome current limitations in hydrogen detectors. • Anodic aluminum oxide (AAO) nanowell array has been selected as substrate because it provides a robust, insulating, and ordered structure for catalyst deposition. • Pd nanoparticles have been selected as catalyst due to their high sensitivity and selectivity to react with hydrogen. • The nanostructure is being characterized and tested for hydrogen detection. Dimensions and configuration are being systematically studied to achieve optimal performance. • The electrical resistance of the nanostructure increases with hydrogen concentration due to the formation of a non conductive Pd hydride phase. • Response time is greatly faster compared to that for other nanostructured and micro sensing devices. • Very low hydrogen concentrations can be detected at room temperature without compromising sensitivity. • The main goal is to achieve optimal performance and integrate the nanostructure into modern sensors.