Inside a liquid solution, oriented attachment (OA) is now recognized to be as important a
pathway to crystal growth as other, more conventional growth mechanisms. However, the
driving force that controls the occurrence of OA is still poorly understood. Here, using in-situ
liquid cell transmission electron microscopy, we demonstrate the ligand-controlled OA of
citrate-stabilized gold nanoparticles at atomic resolution. Our data reveal that particle pairs
rotate randomly at a separation distance greater than twice the layer thickness of adsorbed
ligands. In contrast, when the particles get closer, their ligands overlap and guide the rotation
into a directional mode until they share a common {111} orientation, when a sudden contact
occurs accompanied by the simultaneous expulsion of the ligands on this surface. Firstprinciple
calculations confirm that the lower ligand binding energy on {111} surfaces is the
intrinsic reason for the preferential attachment at this facet, rather than on other low-index
facets. |
Publication: Zhu C , Liang S , Song E , et al. In-situ liquid cell transmission electron microscopy investigation on oriented attachment of gold nanoparticles[J]. Nature Communications, 2018, 9(1):421.
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