Potential Controlled Co-Ni Nanowires with Compositional Gradient

Abstract

Co-Ni nanowires with composition gradient were grown by template assisted electrochemical deposition. Using PCTE membrane to grow nanowires makes the deposition of an alloy inside the pores more challenging because the growth is affected by the transport of the electroactive ions into the pores. A novel step-wise deposition-stripping strategy was used to grow NWs with controlled composition along the length of nanowire while maintaining constant the electrolyte composition. A detailed electrochemical analysis was performed to understand and control the Co stripping process, and to demonstrate the applicability of the proposed method. Redox reactions allow us to create custom deposition-stripping programs that enable us to better select and control the potential used to grow the nanowires of controlled composition. Samples were analyzed using scanning electron microscopy (SEM) and EDS. Quantitative analysis performed on samples has revealed that the designed stripping technique and selected potentials resulted in Co-Ni nanowires with up to 3 times more Ni then the samples obtained from similar electrolyte.