A Route to Grow Oxide Nanostructures Based on Metal Displacement Deposition: Lanthanides Oxy/Hydroxides Characterization

Abstract

Structure and morphology of nanowires (NWs) and nanotubes (NTs) of LnO/OH (Ln = La, Ce, Sm, Er), grown by displacement reaction inside anodic alumina membranes (AAM), were investigated as function of the deposition time and electrolytic bath temperature. Depositions performed at 6°C gave only tubular morphology for all lanthanides oxides, whose height increased with cementation time up to a complete filling of the template pores. For Sm and La cementation conducted at room temperature, a morphology change from mostly tubular, for short immersion times, to a mixture of NWs and NTs with increasing height was found, whilst for Ce and Er only NTs were found. AU nanostructures grown at 60°C showed a NWs morphology and limited heights. Regardless of temperature, a crystalline structure was formed only in the case of CeCO2, whilst the other oxy/hydroxides were amorphous or strongly disordered. In the former case, bath temperature influenced slightly crystallite size. However, after cementation at 60°C, few broad and low intensity peaks appear in the diffraction patterns of Sm and Er oxy/hydroxides. Current investigations show that using this simple method it is also possible to grow nanostructures of mixed oxy/hydroxides of different metals. © 2012 The Electrochemical Society. All rights reserved.