The self-assembly of nanoparticles (NPs) has been extensively studied because of the possibility in solving energy and environmental problems by development of new catalysis, solar cells, and ion storage batteries. The assembly of NPs has relied on the weak inter-particle interactions such as hydrogen bonding, electrostatic interactions and van der Waals forces. Among the relatively weak forces, coordination bonding is one of the promising ways to achieve the self-assembly of NPs, because the assembly process can be controlled by a judicious choice of metal ions and surfactants. However, to date, coordination bonding as a strategy for the self-assembly has been confined to the synthesis of molecular materials. Herein, we demonstrate the coordination assembly of NPs.The disk shape NPs of Iron (II) pyrite were synthesized with thioglycolic acid as a surfactant; thus the carboxyl groups, which is capable to form the coordination bond with metal ion, were exposed at the outer shell of the NPs. By mixing the NPs and metal chlorides, the sheet structures of several-hundred nm width and ten nm thickness were obtained. The sheet structure was characterized by infrared spectroscopy (IR), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and small angle X-ray scattering (SAXS). The series of measurements suggested that the NPs were bridged by the coordination bonds, and spontaneously assembled into the sheet structure. The disk shape NPs were preferentially oriented along the surface normal direction of the sheet structure most likely due to the electrostatic repulsion between the particles.

Coordination assembly of iron(II) pyrite nanoparticles

248th National Meeting (2014)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.