Solvothermal Synthesis of Alloyed PtNi Colloidal Nanocrystal Clusters (CNCs) with Enhanced Catalytic Activity for Methanol Oxidation

Abstract Colloidal nanocrystal clusters (CNCs), which are composed of many nanocrystal subunits, have attracted intensive attention because they can possess not only the properties of each single subunit but also the collective properties and novel functionalities resulting from the ensembles. However, to date, the successful preparation of metal CNCs has rarely been reported. In this work, a simple one‐pot solvothermal method is developed to prepare PtNi‐alloyed CNCs with homogeneous distribution of Pt and Ni elements, porous feature, and interconnected steady framework. The PtNi CNCs are composed of many PtNi nanocrystals with size around 7–8 nm. Their growth mechanism is proposed through a systematic study. Thanks to the unique structure, the as‐prepared PtNi CNCs show better catalytic performance in methanol oxidation reaction than that of PtNi nanocrystals and Pt/C catalysts. This work is important because it not only provides a new method for the preparation of metal CNCs with desired morphology and properties, but also paves the way for practical applications of metal nanoparticles.