Structural Evolution and Compositional Modulation of ZIF-8-Derived Hybrids Comprised of Metallic Ni Nanoparticles and Silica as Interlayer

Great efforts on metal–organic framework (MOF) derived nanostructures have been devoted to modulating the compositional and structural complexities to enhance performance in various applications. However, a facile method that can simultaneously manipulate the structures of the MOF-derived material and the chemical component remains a considerable challenge. Here we report a facile strategy to use the polyhedral ZIF-8 as a precursor for synthesizing ZIF-8-derived hybrids with different components and morphologies. The synthesis involves the preparation of ZIF-8 MOF templates and sequential covering of the ZIF-8 with a interlayer of silica and then polydopamine-Ni2+ (PDA-Ni2+) and carbonizing at different high temperatures under a nitrogen atmosphere, finally leading to ZIF-8-derived hybrids with different components and structures. In the whole process, the preliminary ZIF-8 precursor play a crucial role in the morphology and structure of the final carbonized products, which can be considered as templates for silica coating and precursors of N-doped carbon layer and Zn species. We also found that the SiO2 interlayer coating is a crucial procedure for the formation of yolk–shell structured ZIF-8@SiO2@PDA-Ni2+ composites. Owing to the uniformly distributed Ni NPs and unique structures of the composites, the as-prepared Ni-based composites show high performance in the catalysis of 4-nitrophenol as well as enrichment of histidine-rich proteins. In addition, this proposed strategy for the controllable design and synthesis of ZIF-8-derived nanocomposites paves a new way in developing superior active materials in energy storage conversion etc.