Fabrication, characterization and application of three-dimensional copper nanodomes as efficient cathodes for hydrogen production

Abstract

In this study, three-dimensional (3D) copper nanodomes (Cu-NDs) were fabricated by a combined method of nanosphere-soft lithography, electrochemical and physical vapor deposition (PVD) methods. The 3D Cu-NDs were characterized using surface characterization techniques. The hydrogen production performance and time-stability of the electrodes were examined in a concentrated alkaline solution (6 M KOH) using various electrochemical techniques. The experimental results showed that very uniformly and closely packed Cu-NDs were prepared by the combined methods. The hydrogen generation activity of the 3D Cu-NDs was significantly improved with respect to bulk Cu. Fabricating Cu-NDs does not effect of the hydrogen evolution mechanism and the reaction is activation controlled. The water splitting reaction starts at lower potentials and larger current densities at a fixed potential were appeared at the Cu-NDs electrode. The average reduction in the charge transfer resistance related to the reaction of hydrogen gas evolution is 91.9% at the Cu-NDs electrode with respect to the bulk Cu. The enhanced activity of the nanostructures was related to enlarging real surface area and available more active centers at the Cu-NDs surface. The Cu-NDs electrode has excellent time stability in alkaline solution.