Directed Self-Assembly of MOF-Derived Nanoparticles toward Hierarchical Structures for Enhanced Catalytic Activity in CO Oxidation

The controllable self-assembly of nanomaterials remains a great challenge in nanotechnological applications, especially for the hierarchical structure with high complexity. Herein, by taking the advantage of highly dispersed metal nodes and mild thermal stability of metal-organic frameworks (MOFs), the self-assembly of nanoparticles is directed from MOFs to construct CuO hierarchical structures, which have an inherited octahedral framework consisting of the microspheres, nanowires, and polyhedrons, respectively. Unlike the conventional self-assembly in a solution media (such as solvent and molten solid), the assembly in this work is the first demonstration through a solution-free approach. Moreover, compared to the general MOF-derived CuO octahedron, the assembled hierarchical CuO structure exhibits much enhanced catalytic activity in CO oxidation thanks to the exposure of more active sites during the assembly.