Ultrathin PtCu hexapod nanocrystals with enhanced catalytic performance for electro-oxidation reactions

We first report an effective high-yield (∼100%) synthesis of ultrathin PtCu hexapod nanocrystals. The obtained nanocrystals have three-dimensional (3D) accessible surfaces, and the pod diameter is as thin as only 3.57 nm while the pod length ranges up to 15.28 nm. Moreover, the length and diameter of the pods can be well controlled by simply tuning the amount of NaI added into the system. The formation mechanism is investigated based on the experimental observations, indicating that iodide ions play a critical role in forming the ultrathin PtCu hexapod nanocrystals. Due to their highly open structure and ultrathin pods, the as-prepared ultrathin PtCu hexapod nanocrystals have relatively large surface areas as well as abundant tips and thus exhibit enhanced catalytic activity in the electro-oxidation of methanol and ethanol in comparison with commercial Pt/C, state-of-the-art Pt-based nanodendrites, and PtCu nanoalloy catalysts.