Highly dispersed Ir nanoparticles on TiCT MXene nanosheets for efficient oxygen evolution in acidic media.

The industrialization of hydrogen production technology through polymer electrolyte membrane water splitting faces challenges due to high iridium (Ir) loading on the anode catalyst layer. While rational design of oxygen evolution reaction (OER) electrocatalysts aimed at effective iridium utilization is promising, it remains a challenging task. Herein, we present exfoliated TiCT MXene as a highly conductive and corrosion-resistant support for acidic OER. We develop an alcohol reduction method to achieve uniform and dense loading of ultrafine Ir nanoparticles on the MXene surface. The IrO/TiO heterointerface is formed in situ on the Ir@TiCT MXene surface, acting as a catalytically active phase for OER during electrocatalysis. The electron interactions at the IrO/TiO heterointerface create electron-rich Ir sites, which reduce the adsorption properties of oxygen intermediates and enhance intrinsic OER activity. Consequently, the prepared Ir@TiCT exhibits a mass activity that is 7 times greater than that of the benchmark IrO catalyst for OER in acidic media. In addition, the /TiCT MXene support can stabilize the Ir nanoparticles, so that the stability number of Ir@TiCT MXene is about 2.4 times higher than that of the IrO catalyst.