Formation of CuO<sub>x</sub> Nanowires by Anodizing in Sodium Bicarbonate Solution
Damian Giziński,
Anna Brudzisz,
Mohammad Ramadan Alzahrani,
Kuo-Kuang Wang,
Wojciech Z. Misiołek,
Wojciech J. Stępniowski
Affiliations
Damian Giziński
Institute of Materials Science and Engineering, Faculty of Advanced Technology and Chemistry, Military University of Technologies, 2 Kaliskiego Str., 00908 Warsaw, Poland
Anna Brudzisz
Institute of Materials Science and Engineering, Faculty of Advanced Technology and Chemistry, Military University of Technologies, 2 Kaliskiego Str., 00908 Warsaw, Poland
Mohammad Ramadan Alzahrani
Materials Science and Engineering Department & Loewy Institute, Lehigh University, 5 East Packer Ave., Bethlehem, PA 18015, USA
Kuo-Kuang Wang
Materials Science and Engineering Department & Loewy Institute, Lehigh University, 5 East Packer Ave., Bethlehem, PA 18015, USA
Wojciech Z. Misiołek
Materials Science and Engineering Department & Loewy Institute, Lehigh University, 5 East Packer Ave., Bethlehem, PA 18015, USA
Wojciech J. Stępniowski
Institute of Materials Science and Engineering, Faculty of Advanced Technology and Chemistry, Military University of Technologies, 2 Kaliskiego Str., 00908 Warsaw, Poland
Mechanism of copper nanostructuring by oxides and hydroxide formation during anodizing is not fully understood. At the same time, the search for novel copper anodizing regimes and electrolytes is ongoing due to multiple potential applications. In this work copper anodizing in two electrode setups, in stirred 0.01 M solution of NaHCO3 at 20 °C and at voltages ranging from 5 to 40 V was explored. The morphology and composition of prepared materials were studied using FE-SEM imaging and XRD measurements. Anodizing at potentials in a range of 15–30 V led to formation of nanowires composed of crystalline Cu2O, CuO, Cu(OH)2 and malachite Cu2CO₃(OH)2. The latter was formed due to anion incorporation from the electrolyte. The diameter of nanowires strongly depended on the applied voltage, and was 35 ± 6 nm for samples prepared at 15 V, and 45 ± 9 nm for 30 V. At higher applied voltages oscillations of current density were observed, suggesting partial delamination of the formed oxidized layer, with subsequent self-healing.
