Large-area aligned branched Cu2S nanostructure arrays: Room-temperature synthesis and growth mechanism

In this work, an effective approach to synthesize large-area Cu2S hierarchical nanotree arrays is presented: Cu nanowire arrays synthesized via template-assisted electrodeposition are used as precursors for the self-growth of branched Cu2S nanotree arrays by a gas-solid reaction in H2S atmosphere at room temperature. The branched Cu2S nanotrees with a high aspect ratio are vertically aligned over the Au film surface, forming a nanoscale 'forest'. Electron microscopy studies reveal that the treelike branched nanostructures are composed of an end-capped tubular Cu2S trunk and radially organized Cu2S nanorod branches over the trunk. A formation mechanism of the hollow trunk and the nanobranches is proposed on the basis of experimental observations.