Interface catalytic reduction of alumina by nickle for the aluminum nanowire growth: Dynamics observed by in situ TEM

Abstract

Metal nanowires show promise in a broad range of applications and can be fabricated via a number of methods, such as vapor–liquid–solid process and template-based electrodeposition. However, the synthesis of Al nanowires (NWs) is still challenging from the stable alumina substrate. In this work, the Ni-catalyzed fabrication of Al NWs has been realized using various Al2O3 substrates. The growth dynamics of Al NWs on Ni/Al2O3 was studied using in situ transmission electron microscopy (TEM). The effect of alumina structures, compositions, and growth temperature were investigated. The growth of Al NWs correlates with the Na addition to the alumina support. Since no eutectic mixture of nickel aluminide was formed, a mechanism of Ni-catalyzed reduction of Al2O3 for Al NWs growth has been proposed instead of the vapor–liquid–solid mechanism.