Seoul National University College of Engineering announced that Professor Jungwon Park’s research team from the Department of Chemical and Biological Engineering has developed a groundbreaking technology to observe atomic structural changes of nanoparticles in three dimensions. This study, recognized as a revolutionary achievement that resolves a long-standing challenge even past Nobel laureates could not solve, was published online in Nature Communications, one of the most prestigious international journals, on January 29.

Two experiment collaborations, the g2p and EG4 collaborations, combined their complementary data on the proton’s inner structure to improve calculations of a phenomenon in atomic physics known as the hyperfine splitting of hydrogen. An atom of hydrogen is made up of an electron orbiting a proton. The overall energy level of hydrogen depends on the spin orientation of the proton and electron. If one is up and one is down, the atom will be in its lowest energy state. But if the spins of these particles are the same, the energy level of the atom will increase by a small, or hyperfine, amount. These spin-born differences in the energy level of an atom are known as hyperfine splitting.

The core of this article is to explore the mechanism by which the ruthenium (Ru) integration effect influences ruthenium-cobalt (RuCo) bimetallic nanoparticles in enhancing water-splitting properties. The research team synthesized RuCo bimetallic nanoparticles (RuCo@NC) with atomically dispersed Ru on nitrogen-doped carbon. They found that atomically dispersed Ru not only serves as the primary active site for the hydrogen evolution reaction (HER) but also promotes the oxidation of the Co surface to CoOOH*, thereby becoming a highly active site for the oxygen evolution reaction (OER). The optimized catalyst, RuCo@NC-1, exhibited outstanding performance. In alkaline conditions, it required only 217 and 96 mV of overpotential to reach a current density of 10 mA‧cm⁻² for OER and HER, respectively. This study offers valuable insights into the design of Ru-based electrocatalysts for water splitting.

In this study, the controllable synthesis of highly stable Ag₅₆ clusters was achieved using 4-vinylbenzoic acid (abbreviated as p-VBA) and tert-butyl mercaptan as ligands by precisely regulating reaction parameters such as temperature and solvent. Furthermore, the intermediates Ag₂₀, Ag₃₁, Ag₃₂ and the dimers of the intermediate Ag₃₁/Ag₃₂, Ag₃₀-bpbenz (bpbenz, 1,4-di(4-pyridyl)benzene) and Ag₃₁-bpe (bpe, 1,2-bis(4-pyridyl)) were successfully captured. This series of nanoclusters exhibited a unique fluorescence aggregation-induced redshift phenomenon as the π–π interaction of the ligand. In addition, the Ag₅₆ nanocluster can be used as near infrared fluorescence sensors for Br⁻/I⁻ and their detection limits were as low as 85 and 105 nM, respectively. The results of this study provide new ideas and methods for the synthesis of metal clusters and their applications in the field of ion sensing.