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The galvanic-cell-based synthesis is considered as an effective method for the seed-layer free preparation of ZnO nanorods. However, the nucleation stage of the growth which decides the final structures of ZnO nanorods is still not well-understood. Here we show that the nucleation is almost completed after two minutes of growth and the galvanic-cell-based method results in a condensed ZnO layer beneath of the ZnO nanorods. Beyond this finding, we propose a hybrid approach that combines the galvanic and hydrothermal growth to fabricate the condensed-layer free, well-separated ZnO nanorods that might be compatible for the ZnO-based devices. [ABSTRACT FROM AUTHOR]

Abstract: Oriented hydroxyapatite nanoclusters were achieved by reflux method in the presence of non-poisonous and well dissolved surfactant (potassium polyoxyethylene laurylether phosphate, MAEPK). Transmission electron microscopy (TEM) demonstrated uniform sizes of nanorods arranged in parallel to each other along the c-axis and formed partially oriented nanoclusters in the presence of MAEPK. The sizes of each nanoparticle were about 60–80nm in length and 20nm in width. MAEPK had an important impact on the morphology of product due to the structure of surfactant and a strong electrostatic interaction between ionized MAEPK and Ca2+ ions. The regulating formation mechanism of hydroxyapatite nanoclusters by MAEPK may extend the understanding of biomineralization process for the preparation of biomimetic materials. [Copyright &y& Elsevier]

Abstract: CuO nanorods with thin diameter of about 5nm were prepared at 50°C with the assistance of polyethylene glycol (PEG) as growth directing agent, and these thin rods had a strong tendency to aggregate with parallel orientation. PEG was found to be effective for controlling the size of CuO, and the length of CuO nanorods was decreased by increasing the molecular weight of PEG. CuO nanoparticles with size ranging from 80 to 100nm were produced if polyethylene oxide (PEO) 400,000 was employed. The CuO samples were characterized by SEM, TEM, and XPS techniques. The band gap of CuO nanorods is estimated to be 2.30eV according to the UV–vis absorption spectrum, and such value is larger than that for bulk CuO probably due to the quantum confinement effect. [Copyright &y& Elsevier]