Problem Statement and Motivation

Key Achievements and Future GoalsTechnical Approach

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, UICH.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.

• 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.

• 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.

Pd nanoparticleAAO nanowell

Al substrate

Change in resistance in presence of hydrogen at different concentrations

0.727

0.728

0.729

0.73

0.731

0.732

0.733

0.734

0.735

0 20 40 60 80 100 120 140 160

Time (s)

Res

ista

nce

(kO

hm)

1% H

0.5% H

0.3% H

0.2% H

0.1% H

0.05% H

H on

H off