title: Solventless synthesis of monodisperse Cu2S nanorods, nanodisks, and nanoplatelets.
abstract: Cu(2)S nanocrystals with disklike morphologies were synthesized by the solventless thermolysis of a copper alkylthiolate molecular precursor. The nanodisks ranged from circular to hexagonal prisms from 3 to 150 nm in diameter and 3 to 12 nm in thickness depending on the growth conditions. High resolution transmission electron microscopy (HRTEM) revealed the high chalcocite (hexagonal) crystal structure oriented with the c-axis ([001] direction) orthogonal to the favored growth direction. This disk morphology is thermodynamically favored as it allows the extension of the higher energy [100] and [110] surfaces with respect to the [001] planes. The hexagonal prism morphology also appears to relate to increased C-S bond cleavage of adsorbed dodecanethiol along the more energetic [100] facets relative to [001] facets. Monodisperse Cu(2)S nanodisks self-assemble into ribbons of stacked platelets. This solventless approach provides a new technique to synthesize anisotropic metal chalcogenide nanostructures with shapes that depend on both the face-sensitive thermodynamic surface energy and the surface reactivity.
authors.affiliation: Department of Chemical Engineering, Texas Materials Institute, Center for Nano- and Molecular Science and Technology, The University of Texas at Austin, Austin, Texas 78712-1062, USA.
authors.forename: Michael B
authors.initials: MB
authors.lastname: Sigman
authors.forename: Ali
authors.initials: A
authors.lastname: Ghezelbash
authors.forename: Tobias
authors.initials: T
authors.lastname: Hanrath
authors.forename: Aaron E
authors.initials: AE
authors.lastname: Saunders
authors.forename: Frank
authors.initials: F
authors.lastname: Lee
authors.forename: Brian A
authors.initials: BA
authors.lastname: Korgel