Fabrication of copper nanowires using overpotential electrodeposition and anodic aluminium oxide template

Overpotential is widely used in electrodeposition of copper nanowires (Cu NWs). However, the value of >2 is harmful for nanowires formation. In this reported study, pulse technology is used to solve the problem. The authors have investigated the effects of potential and voltage mode on the formation of Cu NWs via a porous anodic aluminium oxide template using the electrochemical deposition method. Cu NWs were synthesised by electrochemical deposition in 0.2 M CuSO₄-based solution under different potential modes of direct current (DC) and pulse. Scanning electron microscopy and grazing incidence X-ray diffraction were used to examine the nanostructure, morphology and phase of Cu NWs. The Cu NWs deposited by pulse mode exhibited a high aspect ratio despite a high potential of 2-3 V, whereas that at higher DC potential was rather short because of hydrogen generation in reduction reaction. The hydrogen byproduct during Cu NWs synthesis can be effectively released at the off period of pulse deposition for good nanowires formation.