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Researchers at Sweden’s Chalmers University of Technology have developed the first hydrogen sensors ever to meet the future performance targets for use in hydrogen-powered vehicles. The device is capable of detecting 0.1 percent hydrogen in the air in less than a second.
In a study published in the scientific journal Nature Materials, physicists Ferry Nugroho, Christoph Langhammer and other colleagues, explain that their optical nanosensor contains millions of metal nanoparticles of a palladium-gold alloy, a material that is known for its sponge-like ability to absorb large amounts of hydrogen. The device is also encapsulated in a plastic material.
Hydrogen sensor. Photo by Mia Halleröd Palmgren, Chalmers University of Technology.
The sensor’s performance is based on an optical phenomenon that occurs when metal nanoparticles are illuminated and capture light of a certain wavelength. This phenomenon is known as a plasmon. The plasmon then causes the sensor to change colour when the amount of hydrogen in the environment changes.
At the same time, the plastic around the sensor accelerates the uptake of the hydrogen gas molecules into the metal particles where they can be detected, this allows it to increase its response time. The plastic also acts as an effective barrier to the environment, preventing any other molecules from entering and deactivating the sensor.
“We have not only developed the world’s fastest hydrogen sensor, but also a sensor that is stable over time and does not deactivate. Unlike today’s hydrogen sensors, our solution does not need to be recalibrated as often, as it is protected by the plastic,” Nugroho said in a media statement.
In Nugroho and his colleagues’ view, the sensor could be part of a major breakthrough for hydrogen-powered vehicles because, in order for hydrogen cars and the associated infrastructure of the future to be sufficiently safe, it must be possible to detect extremely small amounts of hydrogen in the air and, therefore, sensors that are quick enough to detect leaks before a fire occurs are key.
According to Langhammer, the sensor could also be used in the electricity network industry, the chemical and nuclear power industry, and can also help improve medical diagnostics.
