Copper oxide nanowire

Copper oxide (CuO) nanowires also form a pH-sensitive material. The sensitivity of this metal oxide nanowires is ascribed to their enhanced surface-to-volume ratio. 

Porous aluminum oxide can be used as a template for the production of nanowires and nanotubes. For example, metals can be deposited on the pore walls by the following procedures deposition from the gas phase, precipitation from solution by electrochemical reduction or with chemical reducing agents, or by pyrolysis of substances that have previously been introduced into the pores. Wires are obtained when the pore diameters are 25 nm, and tubes from larger pores the walls of the tubes can be as thin as 3 nm. For example, nanowires and nanotubes of nickel, cobalt, copper or silver can be made by electrochemical deposition. Finally, the aluminum oxide template can be removed by dissolution with a base. 

Students construct an electrochemical cell with a nickel wire cathode and a copper plate as the anode. One side of an aluminum oxide filter with 20 nm diameter channels is exposed to a nickel plating solution when attached to the copper electrode. Gallium-indium eutectic paint is applied to the other side of the filter in order to maintain electrical contact with the electrode. Students connect the electrodes to a 1.5 V battery for approximately 30 minutes as the nickel cations are reduced to nickel metal within the filter pores. Nickel nanowires grow at a rate of approximately 1 micrometer per minute. 

Investigations have been conducted with polycarbonate track-etched templates, aluminum oxide membranes and nonporous mica [344-352], and in all cases the nanomaterial preparation consists primarily of a controlled electrodeposition of copper from a precursor solution (usually CUSO4) inside the nanochannels of the template. In a second step, the template is removed, thus releasing the elongated nanostructures. By following this approach, Gao and coworkers [353] prepared dense and continuous copper nanowires which were 30 xm long and had a uniform... 

Gerein, N.J. and Haber, J.A. (2005) Effect of electrodeposition conditions on the growth oh high aspect ratio copper nanowires in porous alumina oxide templates. Journal of Physical Chemistry E, 109, 17372-85. 

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