Pulse Electrodeposition of Cu–ZnO and Mn–Cu–ZnO Nanowires

Abstract

Cu–ZnO and Mn–Cu–ZnO nanowires are attractive catalysts for alcohol synthesis from CO hydrogenation reactions. Nanowire alloys are pulse electrodeposited into track etched polycarbonate membranes using aqueous electrolytes including , , , and . Pulse waveforms with a cathodic current density of for 50 ms (on-time), with varying off-times (400, 500, and 600 ms), are used to fabricate nanowire arrays (400 nm diameter, long, and pore density of ). Pulse waveforms allow significantly higher copper concentrations and better control of zinc and manganese concentrations within nanowires. X-ray diffraction results show preferential growth in the (111) direction and crystallite size increases with an increase in off-time. Waveforms with longer off-times (500 and 600 ms) resulted in nanowires with relatively higher copper concentrations due to improved copper transport in nanopores. The nanowire surface has no manganese; however, the core shows manganese, which increases with the decrease in off-time. The effect of deposition conditions and electrolyte composition on nanowire properties are explained and discussed.