Directional Migration and Rapid Coalescence of Au Nanoparticles on Anisotropic ReS<sub>2</sub>.

Cao, Yadi; Sun, Yinghui; Yang, Huanhuan; Zhou, Liang; Huang, Qianming; Qi, Jiajie; Guan, Pengfei; Liu, Kaihui et al. · Nano Lett · 2023

basic_science · Level V

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Abstract

Interfacial atomic configuration and its evolution play critical roles in the structural stability and functionality of mixed zero-dimensional (0D) metal nanoparticles (NPs) and two-dimensional (2D) semiconductors. <i>In situ</i> observation of the interface evolution at atomic resolution is a vital method. Herein, the directional migration and structural evolution of Au NPs on anisotropic ReS<sub>2</sub> were investigated <i>in situ</i> by aberration-corrected transmission electron microscopy. Statistically, the migration of Au NPs with diameters below 3 nm on ReS<sub>2</sub> takes priority with greater probability along the <i>b</i>-axis direction. Density functional theory calculations suggest that the lower diffusion energy barrier enables the directional migration. The coalescence kinetics of Au NPs is quantitatively described by the relation of neck radius (<i>r</i>) and time (<i>t</i>), expressed as <math xmlns="http://www.w3.org/1998/Math/MathML"><msup><mrow><mi>r</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>=</mo><mi>K</mi><mi>t</mi></math>. Our work provides an atomic-resolved dynamic analysis method to study the interfacial structural evolution of metal/2D materials, which is essential to the study of the stability of nanodevices based on mixed-dimensional nanomaterials.