Synthesis of PtCo nanotwinned catalysts via laser ablation

Nanotwinned materials possess exceptional properties and represent a promising class of metastable materials. However, their controlled synthesis remains challenging. Here, we report the synthesis of twinned PtCo nanoparticles via a laser ablation approach, which promotes the formation of unique nanostructures. By optimizing laser parameters such as power and exposure time, we achieved a nanotwinning yield up to 61%, significantly higher than 12% in commercial PtCo. In proton-exchange membrane fuel cell tests, the nanotwinned PtCo catalyst demonstrated a mass activity of 0.56 A·mg_Pt⁻¹ with 82.1% retention after accelerated stress testing. Notably, the voltage loss at 1 A·cm⁻² was only 24.3 mV. Particle agglomeration and the reduction of stacking fault energy through alloying were identified as possible mechanisms for nanotwin formation. This work provides an efficient and rapid route for the controlled synthesis of nanotwinned particles, and the approach could potentially enable scalable production of high-performance catalysts.