Lili Han,*, Chen Sun, Hsiao-Tsu Wang,* Wei-Xuan Lin, Jeng-Lung Chen, Chih-Wen Pao,Yu-Chun Chuang, Chia-Hsin Wang, Jigang Zhou, Jian Wang, Way-Faung Pong, and Huolin L. Xin* (*Corresponding Author), Nano Lett. 2024, 24, 7645−765
Unveiling the Growth Secrets of Bimetallic Nanoparticles: A Breakthrough in Nanoscience
Our lab’s latest publication in Nano Letters, a top-tier American nanotechnology journal, presents a groundbreaking discovery in the field of nanomaterials. By leveraging advanced in-situ synchrotron X-ray techniques, we’ve explored the true growth mechanisms of 3d transition bimetallic nanoparticles, paving the way for crucial future material design and applications.
The core of this research lies in providing a more precise method for controlling nanomaterial growth. By gaining a deep understanding of the nucleation and growth processes of Fe-Ni bimetallic nanoparticles, scientists can now more effectively design bimetallic nanostructures with specific functionalities. These include materials possessing superior magnetic, electron transport, and catalytic properties, holding vast potential for applications in biomedical, energy, and electronics fields.
Traditional ex-situ experiments often fall short in capturing the intermediate states of materials during synthesis. Our study, however, overcomes these limitations by employing synchrotron X-ray technology to observe the dynamic changes of nanoparticles in real time. This allowed for an in-depth understanding of the transformations in their crystalline, atomic, and electronic structures.
During the experiments, our research team tracked the growth of Fe-Ni nanocrystals starting from their precursors. Using in-situ techniques such as high-resolution X-ray Diffraction (XRD), X-ray Absorption Spectroscopy (XAS), and Scanning Transmission X-ray Microscopy (STXM), we observed phase transitions and changes in oxidation states as the temperature varied.
The results revealed that Ni first reduces to its metallic state, subsequently guiding Fe to gradually incorporate into the structure, ultimately forming a stable Fe-Ni alloy. As the temperature increased, the nanoparticle structure underwent significant transformation, leading to the formation of a γ-Fe₃Ni₂-dominated crystalline structure.
These findings not only unveil the relationship between the microstructure and performance during the growth of Fe-Ni nanoparticles but also provide new perspectives and techniques for the precise design of bimetallic nanomaterials.