posted on 2021-04-01, 10:31authored byMinh T. Pham, Hoang M. Luong, Huy T. Pham, Tyler Guin, Yiping Zhao, George K. Larsen, Tho D. Nguyen
As
hydrogen gas increasingly becomes critical as a carbon-free
energy carrier, the demand for robust hydrogen sensors for leak detection
and concentration monitor will continue to rise. However, to date,
there are no lightweight sensors capable of meeting the required performance
metrics for the safe handling of hydrogen. Here, we report an electrical
hydrogen gas sensor platform based on a resistance nanonetwork derived
from Pd-Co composite hole arrays (CHAs) on a glass substrate, which
meets or exceeds these metrics. In optimal nanofabrication conditions,
a single poly(methyl methacrylate)(PMMA)-coated CHA nanosensor exhibits
a response time (t80) of 1.0 s at the
lower flammability limit of H2 (40 mbar), incredible sensor
accuracy (<1% across 5 decades of H2 pressure), and
an extremely low limit of detection (LOD) of <10 ppb at room temperature.
Remarkably, these nanosensors are extremely inert against CO and O2 gas interference and display robust long-term stability in
air, suffering no loss of performance over 2 months. Additionally,
we demonstrate that the unique nanomorphology renders the sensors
insensitive to operation voltage/current with diminutive power requirement
(∼2 nW) and applied magnetic field (up to 3 kOe), a crucial
metric for leak detection and concentration control.