A colloquium on the status and challenges in science for decarbonizing our energy landscape

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 HClO₄ 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 IrO₂ 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.