Fabrication and morphological control of Ni-based nanowires by self-assembled solution synthesis

In this study, we investigated the formation of Ni-based nanowires (NWs) and precise control of their surface morphology via solution synthesis. Ni²⁺ ions were reduced to metallic Ni with hydrazine, and Ni nanoparticles were formed in ethylene glycol solution. The Ni nanoparticles then self-assembled along one direction to form NWs. The surface morphology of the Ni NWs depended on the hydrazine concentration. Needle-like protrusions were formed on the surfaces of the Ni NWs at high hydrazine concentrations, whereas Ni NWs with smooth surfaces were obtained at low hydrazine concentrations. The inclusion of NaBH₄ as a proportion of the reducing agent led to the formation of NWs containing a Ni-B alloy. The catalytic activity of the NWs containing a Ni-B alloy in H₂ generation from NaBH₄ solution was higher than that of the Ni NWs.