IrNi Nanoparticles as Highly Efficient Electrocatalysts Towards the Oxygen Evolution Reaction in an Acidic Medium

The development of efficient and durable bifunctional electrocatalysts for oxygen evolution reaction (OER), still poses huge challenges. Herein, we utilize a facile hydrothermal method to synthesize a novel IrNi nanocrystals. In particular, the electronic structure is altered when a portion of the iridium atom is replaced by a Ni atom, which causes the center of the d band to shift downward, favoring the catalytic reaction. The overpotentials for OER of 273 mV at a current density of 10 mA cm−2, exceed the capabilities of commercial Ir catalysts. The alloying of Ir with Ni reduces the adsorption energy of oxygen intermediates to achieve a fast oxygen evolution reaction. This work highlights a potentially powerful strategy toward the general synthesis of novel, Ir-based alloy as highly active and durable bifunctional electrocatalysts for high-performance electrochemical overall-water-splitting devices.