Ultrathin Ir nanowires as high-performance electrocatalysts for efficient water splitting in acidic media

Abstract

The search for active and stable bifunctional electrocatalysts toward acidic overall water splitting is under increasing demand for the development of polymer electrolyte membrane (PEM) electrolyzers. However, developing bifunctional electrocatalysts with Pt-like activity and superior stability under acidic media still remains a big challenge. Herein, we report a successful synthesis of Ir wavy nanowires with an ultrathin diameter of 1.7 nm through a simple wet-chemical approach. Benefiting from the unique morphology with high aspect ratios and a large specific surface area, the as-synthesized ultrathin Ir wavy nanowires exhibit enhanced activity and durability for both the oxygen evolution reaction and the hydrogen evolution reaction in acidic electrolytes. Moreover, when used for overall acidic water splitting, a current density of 10 mA cm⁻² is achieved at only a cell voltage of 1.62 V in 0.1 M HClO₄ electrolyte with long-term stability. In view of the excellent electrochemical water splitting performance and superior stability in acidic electrolytes, we believe that the obtained Ir wavy nanowires could be potential alternative catalysts toward PEM water electrolysis.