The depletion of fossil fuels and public reluctance toward nuclear energy have made power generation using hydrogen energy and the introduction of hydrogen vehicles inevitable. However, because hydrogen atoms are very small, the risk of explosion from leaks is high, so strict management is required during hydrogen production, storage, transport, and use. Various types of hydrogen gas detectors have been developed for this purpose. Among them, conventional semiconductor gas sensors have attracted attention as hydrogen leak detectors because they can easily detect low-concentration hydrogen leaks and are inexpensive. However, they have the drawback of insufficient selectivity for hydrogen, as they also respond to other gases such as CO.

To dramatically overcome these shortcomings of existing semiconductor hydrogen gas sensors, Professor Yeon-Tae Yu (College of Engineering, Division of Advanced Materials Engineering, Information Materials Engineering) and PhD candidate Tuong Van Tran developed a "highly active, highly selective hydrogen gas sensing material." Their paper was published in the March 2024 issue (Vol. 483) of Chemical Engineering Journal (Impact factor: 16.744), a leading international journal in the fields of nanomaterials and catalysis. The title of the paper is "Alloy core composition effect of Pd-Augr-alloy@ZnO core–shell nanoparticles on hydrogen gas sensing performance."

The sensing material developed by Professor Yu’s research team is spherical core–shell nanoparticles. For the core, they used Pd–Au alloy nanoparticles, a hydrogen storage alloy, to dramatically improve selectivity for hydrogen gas. For the shell, they applied zinc oxide (ZnO) nanoparticles, a semiconductor material. This combination simultaneously enhanced reactivity to hydrogen and selectivity (26 times over CO, 15 times over methane, and 13 times over ethanol). Using this nanomaterial makes it possible to develop inexpensive semiconductor gas sensors with high selectivity for hydrogen gas.

Professor Yeon-Tae Yu explained the significance of the research: "Alloy@MOS (Metal Oxide Semiconductor) core–shell structured nanoparticles are not only capable of improving hydrogen selectivity in semiconductor gas sensors but can also be utilized as highly efficient photocatalysts for producing hydrogen via water splitting. Therefore, further research is highly anticipated."

Meanwhile, this research was carried out with support from the Mid-Career Researcher Support Program of the National Research Foundation of Korea and the BK21-FOUR project (Smart Electronic Information Materials Talent Training Team, Team Leader Yeon-Tae Yu), among other sources.