Cu2O Nanowires in an Alumina Template: Electrochemical Conditions for the Synthesis and Photoluminescence Characteristics

• Published in: Chemphyschem 2006-07, Vol.7 (7), p.1505-1509
• Main Authors: Ko, Eunseong, Choi, Jinsub, Okamoto, Koichi, Tak, Yongsug, Lee, Jaeyoung
• Format: Article
• Language: English
• Subjects: Chemistry; Colloidal state and disperse state; Cross-disciplinary physics: materials science; rheology; electrochemistry; Exact sciences and technology; General and physical chemistry; Materials science; mesoporous materials; metal oxides; nanowires; Physics; Porous materials; Specific materials; X‐ray diffraction
• ISSN: 1439-4235; 1439-7641
• DOI: 10.1002/cphc.200600060

10.1002/cphc.200600060.absCu2O nanowires, mainly consisting of (100) and (200) polycrystalline structures with a length of 4 μm are prepared by electrochemical deposition using a porous alumina template. It is found that the optimized electrochemical conditions to prepare Cu2O nanowires are different from those for the formation of a bulk thin Cu2O layer since different pH values are found between the tip of the pores and the bulk, due to diffusion limits in porous alumina with an extremely high aspect ratio of 300. We point out that Cu2O (200), Cu2O (111), Cu, and co‐deposited alloys can be obtained under specific electrochemical conditions. In addition, the optical band gap of the prepared Cu2O nanowires with a length of 4 μm and a diameter of 200 nm is estimated to be 2.17 eV from photoluminescence measurements. Fastidious nanowires: The preparative electrochemical conditions for Cu2O nanowires in a porous alumina template (see microstructure picture) are different to those for a bulk thin Cu2O layer. The nanowires can only be prepared in a pH range from 8 to 10 and under optimized conditions, polycrystalline Cu2O nanowires with a length of 4 μm are obtained.