One-Step Construction of Hydrophobic MOFs@COFs Core-Shell Composites for Heterogeneous Selective Catalysis.

The exploration of novel porous core-shell materials is of great significance because of their prospectively improved performance and extensive applications in separation, energy conversion, and catalysis. Here, mesoporous metal-organic frameworks (MOFs) NH-MIL-101(Fe) as a core generate a shell with mesoporous covalent organic frameworks (COFs) NUT-COF-1(NTU) by a covalent linking process, the composite NH-MIL-101(Fe)@NTU keeping retentive crystallinity with hierarchical porosity well. Importantly, the NH-MIL-101(Fe)@NTU composite shows significantly enhanced catalytic conversion and selectivity during styrene oxidation. It is mainly due to the hydrophilic MOF nanocrystals readily gathering the hydrophobic reactants styrene and boosting the radical mechanism path after combining the hydrophobic COFs shell. The synthetic strategy in this systematic study develops a new rational design for the synthesis of other core-shell MOF/COF-based hybrid materials, which can expand the promising applications.