Ball-flower-shaped Ni nanoparticles on Cu modified TiO2 nanotube arrays for electrocatalytic oxidation of methanol.

Highlights: [•] Highly ordered TiO2 nanotube array modified with copper was used as a substrate. [•] Nickel nanoparticles were deposited on the nanostructured titanium layer by two-step electrodepositon. [•] The nickel nanoparticles showed a ball-flower structure and gave large specific area. [•] This electrode showed remarkably enhanced activity and good stability toward methanol oxidation. [ABSTRACT FROM AUTHOR]