Template-assisted fabrication of Ni nanowire arrays for high efficient oxygen evolution reaction

Abstract

Architecture construction of electrode is one key factor for hydrogen generation from electrochemical water splitting. To enhance the efficiency of oxygen evolution reaction (OER) at high current density, the architecture construction must be designed skillfully to prevent the surface blanketed by gas bubbles. In this work, we developed a three-level hierarchical surface with cluster-like nickel (Ni) nanowire array. The contact angle measurement indicates the surface having excellent hydrophilicity. The OER performance characterization reveals that after the surface is loaded with NiFe-based catalyst the Ni nanowire array electrode can deliver 500 mA cm−2 at an overpotential of 297 mV in 1 M KOH solution and can survive for over 24 h under 500 mA cm−2 operation. All the results demonstrate that the cluster-like nanowire array is beneficial for the spatial pathway separation for electrolyte supply and gas bubbles departure and the enhancement of OER efficiency.