Electrodeposition of nickel nanowires and nanotubes using various templates

Abstract

Nickel nanotubes and nanowires are grown by galvanostatic electrodeposition in the pores of 1000, 100, and 15 nm polycarbonate as well as in anodised alumina membranes at a current density of 10 mA cm À2. The effects of pore size, porosity, electrodeposition time, effective current density, and pore aspect ratio are investigated. Nickel nanotube structures are obtained with 1000 nm pore size polycarbonate membrane without any prior treatment method. At the early stages of electrodeposition hollow nickel nanotubes are produced and nanotubes turn into nanowires at longer depositon times. As effective current density accounting for the membrane porosity decreases, the axial growth direction is favoured yielding nanowires rather than nanotubes. However, for smaller pore size polycarbonate membranes, nanowires are obtained even though effective current densities were higher. We believe that when the pore diameter is below a critical size, nanowires grow regardless of current density since narrow pores promote layer by layer growth of nanorods due to smaller surface area of the pore bottom compared to pore walls. Pore size has a dominant effect over effective current density in determining the structure of the fibres produced for small pores. Nickel nanowires are also obtained in the small pores of anodised alumina, which has higher aspect ratios. High aspect ratio membranes favour the fabrication of nanowires regardless of current density.

Synthesis of High Aspect-Ratio Gold Nanowires with Highly Porous Morphology

“…This then suggests that the deposition process is mass transport controlled, which is not unexpected given the membrane pore dimensions and negative charge on the gold species [62]. Importantly, it can be seen from this data that the actual current density at the cathode (excluding the capacitive "current") is well within the limits for gold deposition with high current efficiency for this plating solution (1.1-10.8 mA/cm 2 ) for effectively the whole deposition period [64]. This means that essentially all of the charge passed was used to reduce the gold species rather than evolve hydrogen gas.…”

“…A second possible explanation is that these structures are in fact incompletely formed gold nanotubes, which can come about due to the reduction of gold species that are preferentially adsorbed on the walls of the membrane pores [61,65]. This explanation was contemplated as the prevailing conditions during the gold deposition; namely, low overpotentials (the reduction potential of gold cyanide is −0.6 V versus Ag/AgCl [66]) and a low gold concentration near the cathode (current versus time data in Figure 7 indicates diffusion limited growth) are conducive to the formation of such gold structures [61].…”

Influence of boric acid (H3BO3) concentration on the physical properties of electrochemical deposited nickel (Ni) nanowires

“…When an electric field is applied, cations diffuse through the channels and deposit on the cathode, resulting in the growth of nanowires inside the pores of the template. For the electrolyte solution preparation, the procedure adopted by Ertan et al [20] was used. It is by far the simplest method and has demonstrated success in synthesizing Ni nanowires using the template-assisted electrochemical deposition method.…”

Fabrication of Highly Ordered Sn Nanowires in Anodic Aluminum Oxide Templates by Using AC Electrochemical Method

“…On the other hand, novel fabrication techniques such as electrodeposition methods (e.g. direct or alternating current techniques) have shown more accurate controllability over materials morphology and chemical composition of nanostructures in comparison to conventional production techniques as well as their easier scalability for industrial applications [55][56][57]. Electrodeposition of metallic alloys in the ordered self-assembled templates (e.g.…”