Coalescence dynamics of platinum group metal nanoparticles revealed by liquid-phase transmission electron microscopy
Joodeok Kim,
Dohun Kang,
Sungsu Kang,
Byung Hyo Kim,
Jungwon Park
Affiliations
Joodeok Kim
School of Chemical and Biological Engineering, Institute of Chemical Processes, Seoul National University, Seoul 08826, Republic of Korea; Center for Nanoparticle Research, Institute of Basic Science (IBS), Seoul 08826, Republic of Korea
Dohun Kang
School of Chemical and Biological Engineering, Institute of Chemical Processes, Seoul National University, Seoul 08826, Republic of Korea
Sungsu Kang
School of Chemical and Biological Engineering, Institute of Chemical Processes, Seoul National University, Seoul 08826, Republic of Korea; Center for Nanoparticle Research, Institute of Basic Science (IBS), Seoul 08826, Republic of Korea
Byung Hyo Kim
Center for Nanoparticle Research, Institute of Basic Science (IBS), Seoul 08826, Republic of Korea; Department of Organic Materials and Fiber Engineering, Soongsil University, Seoul 06978, Republic of Korea; Corresponding author
Jungwon Park
School of Chemical and Biological Engineering, Institute of Chemical Processes, Seoul National University, Seoul 08826, Republic of Korea; Center for Nanoparticle Research, Institute of Basic Science (IBS), Seoul 08826, Republic of Korea; Institute of Engineering Research, College of Engineering, Seoul National University, Seoul 08826, Republic of Korea; Advanced Institutes of Convergence Technology, Seoul National University, Gyeonggi-do 16229, Republic of Korea; Corresponding author
Summary: Coalescence, one of the major pathways observed in the growth of nanoparticles, affects the structural diversity of the synthesized nanoparticles in terms of sizes, shapes, and grain boundaries. As coalescence events occur transiently during the growth of nanoparticles and are associated with the interaction between nanoparticles, mechanistic understanding is challenging. The ideal platform to study coalescence events may require real-time tracking of nanoparticle growth trajectories with quantitative analysis for coalescence events. Herein, we track nanoparticle growth trajectories using liquid-cell transmission electron microscopy (LTEM) to investigate the role of coalescence in nanoparticle formation and their morphologies. By evaluating multiple coalescence events for different platinum group metals, we reveal that the surface energy and ligand binding energy determines the rate of the reshaping process and the resulting final morphology of coalesced nanoparticles. The coalescence mechanism, based on direct LTEM observation explains the structures of noble metal nanoparticles that emerge in colloidal synthesis.
