Trace Amount of Ir Decorated NiFe Phosphide In-Situ Grown on Carbon Cloth as Cost-Effective Electrocatalyst for...

Cost-effective electrocatalysts is a key constituent to establish the balance of cost and catalytic efficiency for oxygen evolution reaction (OER) via water electrolysis in the area of energy conversion and storage. NiFe phosphide decorated with trace amount of iridium (Ir) species in-situ grown on carbon cloth was prepared by a facile wet chemistry approach followed by a phosphorization post-treatment at a relative low temperature. The optimal electrocatalyst, Ir₂-NiFeP_x/CC, exhibits excellent OER activity, with an low overpotential of 190 mV at 10 mA cm^-2 for alkaline OER, and a desirable long-term durability over 90 h. The outstanding OER performance stems from the structural evolution via phosphorization process, Ir decoration with more high-valence stated Ir⁴⁺ species, and tight connection between individual components of the electrode, which gives rise to the strong activity to the active sites and faster reaction kinetics in the alkaline OER process. Mover, the Ir loading was as low as approximately ~1.7 wt % (0.29 mg cm^-2), showing promissing propective in cost-effective OER.