Tomsk Polytechnic University has joined forces with the University of Chemistry and Technology of Prague to develop new sensors based on optical fibre to ensure accurate detection of hydrogen molecules in the air.
It is hoped that in the future the systems will be able to contribute a basis for a ‘hydrogen alarm’ used to detect leaks of explosive hydrogen.
“It is necessary to detect hydrogen molecules in a gas mixture,” said Pavel Postnikov, one of the Authors and Associate Professor of the TPU Research School of Chemistry and Applied Biomedical Sciences.
“Currently, there are various methods, including electronic sensors, although they are a potential source of spark. In this respect, we turned our attention to optical fibre.”
“This is a simple and commercially available material. In addition, a sensor can be operated remotely, since optical fibre provides rapid and easy information transfer over long distances. The sensor can be installed in the engine of a hydrogen-powered machine or refuelling station.”
Optical fibre is a thin filament of optically transparent material, such as glass or plastic, the researchers have modified the optical fibre by removing a fragment of the fibre sheath and applying a fine layer of gold onto this place through magnetron sputtering,
On the surface of this golden area, the effect of surface plasmon resonance arises. It is the source of the analytical signal. The researchers used this golden area from a matrix solution as a basis for a metal-organic framework consisting of zinc molecules and particular organic compounds.
“This frame is extremely sensitive to hydrogen, since it captures it molecules from the air. Moreover, it is inert to other gases. Such sensors are comparable to a stationary chromatograph that is ten times more expensive and requires qualified personnel.”
“For now, we have managed to achieve sensitivity and detection limit below 2%. In order words, our sensor can detect hydrogen in the air at a concentration below 2%, while the lower explosive threshold of a mixture of hydrogen and oxygen is about 4%.”
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