Electrochemical production of nanopore arrays in a nickel aluminium alloy

This study introduces a novel electrochemical method for the fabrication of nanopore arrays within a nickel-aluminium (NiAl) alloy, specifically utilizinga directionally solidified NiAl-Re eutectic system. The initial step involved directional solidification of the NiAl-Re alloy at controlled parameters (e.g., 1690 ± 10°C, 40°C cm⁻¹ gradient, 30 mm h⁻¹ growth rate) to produce uniformly aligned rhenium (Re) fibers, approximately 400 nm in diameter, embedded within the NiAl matrix. Subsequently, an electrochemical process, employing a 1 M acetate buffer at pH 6.0, was developed to selectively electrodissolve the Re fibers while simultaneously passivating the NiAl matrix. This approach successfully yielded ordered nanopore arrays, each pore retaining the 400 nmdiameter of the original Re fibers. The research highlights the mechanisms behind this procedure and discusses its significant potential for applications in nanotechnology, such as the production of nanoelectrode arrays or nanofilters.