Self-templating growth of copper nanopearl-chain arrays in electrodeposition

We report here a unique in-plane self-templating electrochemical growth of arrays of copper nanopearl chains from an ultrathin layer of CuSO4 electrolyte. Scanning electron microscopy indicates that the electrodeposit filaments form equally spaced bundles, which consist of long, straight, pearl-chain-like copper filaments with corrugated periodic structure. The bundle separation can be tuned by changing the applied electric current in electrodeposition. Experiments show that the periodic morphology on the nanopearl chain corresponds to the periodic distribution of copper and cuprous oxide. The mechanism for the bundle formation is discussed.