A Customized Hydrophobic Porous Shell for MOF-5

Thesusceptibility to moisture of metal-organic frameworks(MOFs) is a critical bottleneck for their wider practical application.Constructing core-shell composites has been postulated as aneffective strategy for enhancing moisture resistance, but for fragileMOFs this has rarely been accomplished. We report herein, for thefirst time, the construction of a customized hydrophobic porous shell,NTU-COF, on the particularly fragile MOF-5 by a Plug-SocketAnchoring strategy. Notably, the pore structure of MOF-5 waswell maintained, and it could still achieve complete CO2/N-2 separation under humid conditions. The homogeneousinterface between MOF-5 and NTU-COF has been inspected at atomic resolutionby a combination of cryogenic focused ion beam (cryo-FIB) and ultralow-dose(scanning) transmission electron microscope giving profound insightinto the mechanism of assembly of the core-shell structure.This work presents a facile strategy for the fabrication of a hydrophobicporous shell for labile MOFs, and provides a general approach forsolving the problem of moisture instability of porous materials forpractical applications.

Automated summary

This article presents a method to enhance the moisture resistance of fragile metal-organic frameworks (MOFs) by constructing a customized hydrophobic porous shell, NTU-COF, on MOF-5 using the Plug-Socket Anchoring strategy. It was found that the pore structure of MOF-5 was well preserved and could achieve complete CO2/N-2 separation even under humid conditions. Atomic resolution inspection of the interface between MOF-5 and NTU-COF revealed insights into the assembly mechanism of the core-shell structure.