A analysis group led by Professor Jungwon Park from the Division of Chemical and Organic Engineering at Seoul Nationwide College School of Engineering has developed a novel method for observing atomic structural adjustments in nanoparticles in three dimensions. This research, printed in Nature Communications, addresses a long-standing challenge that earlier Nobel laureates have been unable to resolve.
Significance of Nanoparticles
Nanoparticles are extensively used within the growth of purposeful supplies for industries akin to power, surroundings, and medication. Resulting from their small dimension (1 nm = one-billionth of a meter), they exhibit distinctive bodily and chemical properties. Observing structural adjustments in nanoparticles is essential as a result of their reactivity varies considerably with dimension.
Challenges in Present Strategies
Present strategies for analyzing nanostructures are restricted of their capabilities. These strategies sometimes solely present fundamental structural identification or averaged information from a number of nanoparticles. Moreover, they typically give attention to mounted nanoparticles in a vacuum, making it troublesome to look at three-dimensional atomic buildings over time, particularly in liquid environments.
Developments in Microscopy: From Cryo-TEM to Liquid TEM
Whereas the three-dimensional atomic buildings of proteins have already been decided utilizing cryo-transmission electron microscopy (cryo-TEM), the problem of observing nanoparticles in answer remained unsolved. Professor Park’s group constructed upon this development, growing a brand new methodology referred to as liquid transmission electron microscopy (liquid TEM) utilizing graphene to visualise nanostructures in answer in three dimensions. Their earlier work on this methodology, referred to as Brownian tomography, was featured on the duvet of Science in 2020.
Time-Resolved Brownian Tomography
The newly developed time-resolved Brownian tomography method permits for real-time monitoring of atomic structural adjustments in particular person nanoparticles. This breakthrough methodology opens up new alternatives for understanding how chemical reactions alter nanoparticles on the atomic stage.
Methodology: Remark of Transferring Nanoparticles
Utilizing the “graphene liquid cell transmission electron microscopy (Graphene Liquid Cell TEM)” method, the researchers developed a method to observe freely shifting nanoparticles in answer. Nanoparticles present process Brownian movement (random motion in a fluid) are captured from numerous angles over time, and the ensuing photos are reconstructed right into a three-dimensional mannequin.
Comparability to Conventional Strategies
This methodology marks a major development over conventional transmission electron microscopy (TEM), which analyzes mounted nanoparticles in a vacuum. It’s also an enchancment over spectroscopic strategies that solely present averaged information from a number of nanoparticles. For the primary time, this expertise permits direct measurement of a single nanoparticle’s three-dimensional atomic construction because it dynamically adjustments in a liquid surroundings.
Observations and Outcomes
The group used this method to look at atomic-level structural adjustments in platinum (Pt) nanoparticles in the course of the etching (chemical corrosion) course of. They might monitor, in three dimensions, when floor atoms reattached (re-adsorbed), rearranged, or indifferent (desorbed). Apparently, the research revealed {that a} extremely disordered part appeared when the nanocrystals shrank to roughly 1 nm in dimension, which was surprising since platinum sometimes maintains a extremely ordered atomic construction.
Implications and Future Analysis
The research exhibits that even nanoparticles constructed from the identical elemental materials can exhibit distinct structural traits in comparison with their bigger counterparts. This analysis additionally represents a major development within the commentary of atomic buildings, surpassing conventional TEM and cryo-TEM. Due to this new strategy, scientists can now monitor how the three-dimensional buildings of nanomaterials evolve over time in response to numerous chemical circumstances, such because the composition of reactive options or utilized voltage.
Functions and Influence
The findings provide a extra correct understanding of how structural adjustments affect the performance of next-generation nanomaterials, together with metals, semiconductors, and oxides. Moreover, the research, funded by the Nationwide Hydrogen Precedence Analysis Heart undertaking, efficiently detected structural adjustments in platinum nanoparticles, that are important catalysts for environmentally pleasant hydrogen power purposes. This paves the way in which for the event of high-performance catalysts sooner or later.
The event of ‘time-resolved Brownian tomography’ continues the legacy of the 2017 Nobel Prize-winning ‘cryo-TEM’ and our 2020 Science cover-featured ‘liquid TEM’ innovation. This new method will considerably contribute to unraveling advanced response mechanisms in hydrogen gas cells, CO₂ conversion catalysts, lithium-ion batteries, and different superior power supplies, facilitating the design of superior supplies.
Jungwon Park, Professor and Analysis Lead, School of Engineering, Seoul Nationwide College
The Examine’s Lead Writer, Researcher Sungsu Kang, remarked, “Our analysis immediately captured real-time atomic-level structural adjustments of nanocrystals in liquid environments. This achievement is especially vital as a result of it efficiently visualized floor atomic actions and the emergence of recent phases distinctive to nanomaterials phenomena that have been difficult to detect utilizing standard spectroscopic or electrochemical strategies.”
Sungsu Kang is at the moment a Postdoctoral Researcher on the College of Chicago. He earned his Ph.D. from SNU’s College of Chemical and Organic Engineering. He continues to refine the “time-resolved Brownian tomography” methodology, increasing its software to numerous nanomaterials and exploring their potential makes use of in chemical environments.
Journal Reference:
Kang, S., et al. (2025) Time-resolved Brownian tomography of single nanocrystals in liquid throughout oxidative etching. Nature Communications. doi.org/10.1038/s41467-025-56476-8.
