This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: A team led by principal researcher Myungkwan Song of the Energy & Environment Materials Research Division at the Korea Institute of Materials Science (KIMS) has developed an ultrasensitive ammonia gas sensor using an environmentally friendly, lead-free perovskite material. In addition to developing the high-performance sensor, the researchers elucidated, for the first time, the mechanism by which it detects ammonia, providing a new direction for the development of next-generation perovskite-based gas sensors.
The technology is expected to serve as a key gas-detection solution for improving safety in an emerging hydrogen economy that uses ammonia as an energy carrier. The research was conducted in collaboration with teams led by Professor Hyung Woo Lee of Pusan National University, Professor Youngho Kang of Incheon National University, and Professor Jincheol Kim of Macquarie University in Australia. The study is published in the journal Small Structures.
Ammonia has recently attracted significant attention as a next-generation hydrogen carrier because it can facilitate the storage and transportation of hydrogen, which is otherwise difficult to handle. As a result, ammonia is emerging as an important material in the growing hydrogen economy. However, even small ammonia leaks can be harmful to human health.
High-performance sensors capable of immediately detecting trace leaks are therefore essential at storage and transportation facilities, power plants and industrial sites. In particular, exposure to ammonia at concentrations of only several tens of parts per million can affect worker health, creating a need for more sensitive and accurate detection technologies. Conventional perovskite-based gas sensors can detect ammonia with high sensitivity, but most contain lead (Pb), which is harmful to human health and the environment and limits their potential for commercialization.
To address this issue, the research team developed a lead-free perovskite based on antimony (Sb), known as formamidinium antimony bromide (FA₃Sb₂Br₉), and applied it as the active sensing material in an ammonia gas sensor. The resulting device achieved both environmental advantages and excellent sensing performance. The sensor reliably detected ammonia at concentrations as low as 1 ppm.
Its signal increased consistently as the ammonia concentration rose, demonstrating its ability to quantitatively determine ammonia concentrations. When exposed to ammonia at a concentration of 100 ppm, the sensor responded in just 13 seconds, while its electrical signal increased by as much as 235%, demonstrating outstanding sensing performance. The sensor also showed substantially lower responses to other gases, including methane (CH₄), carbon monoxide (CO), nitrogen oxides (NOₓ), hydrogen (H₂) and methanol (MeOH), confirming its high selectivity for ammonia.
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