Plasma-Assisted Synthesis in Aqueous Solution to Prepare Ir-Based Nanocatalysts for Oxygen Evolution Reaction in Acidic Conditions

Green hydrogen production is a key factor in reaching climate goals. Proton exchange membrane water electrolysis (PEMWE) is one of the most promising technologies to achieve this, but it is limited by the poor electrocatalytic activity of the oxygen evolution reaction (OER), which requires high loadings of expensive and scarce precious metals, such as iridium. In this study, we synthesized iridium nanoparticles supported on titanium-oxynitride-decorated reduced graphene oxide (TiON/C). The prepared materials have been characterized using a variety of physicochemical methods, and the OER activity of iridium-based catalysts was assessed by cyclic voltammetry in acidic media. The plasma-assisted synthesis approach enables the preparation of electrocatalysts without the need for reducing agents, high-temperature annealing, or any other post-treatment. An outstanding mass-specific activity value of 11,700 A g–1 reached at 1.6 VRHE was obtained for the prepared Ir/TiON/C catalyst. The small Ir particle size and strong Ir–TiON interactions contribute significantly to the enhanced OER activity and good stability, demonstrating the potential of this material for efficient and sustainable hydrogen production with PEMWE.