A Simple Method for Synthesizing Highly Active Amorphous Iridium Oxide for Oxygen Evolution under Acidic Conditions

Water splitting for hydrogen production has been recognized as a promising approach to store sustainable energy. The performance of this method is limited by the oxygen‐evolution reaction. Herein, an approach for synthesizing a highly active oxygen‐evolving catalyst by a one‐step, low‐cost, environmentally friendly, and easy‐to‐perform method is presented, which works by using iridium metal as the anode at a relatively high potential. The obtained IrO x /Ir interface showed an overpotential of 250 mV at 10 mA cm −2 in 0.1 m HClO 4 and remained stable under electrochemical conditions. The IrO x that was mechanically separated from the surface of IrO x /Ir metal after operation showed a threefold increase in activity compared to the current benchmark IrO 2 catalyst. Various characterization analyses were used to identify the structure and morphology of the catalyst, which suggested nanosized, porous, and amorphous IrO x on the surface of metallic Ir. This synthetic approach can inspire a variety of opportunities to design and synthesize efficient metal oxide‐based electrocatalysts for sustainable energy conversion and utilization.