Void Engineering in Metal–Organic Frameworks via Synergistic Etching and Surface Functionalization

Abstract

The rational design and engineering of metal-organic framework (MOF) crystals with hollow features has been used for various applications. Here, a top-down strategy is established to construct hollow MOFs via synergistic etching and surface functionalization by using phenolic acid. The macrosized cavities are created inside various types of MOFs without destroying the parent crystalline framework, as evidenced by electron microscopy and X-ray diffraction. The modifi ed MOFs are simultaneously coated by metal-phenolic fi lms. This coating endows the MOFs with the additional functionality of responding to near infrared irradiation to produce heat for potential photothermal therapy applications.

Hollow Zn−Co Based Zeolitic Imidazole Framework as a Robust Heterogeneous Catalyst for Enhanced CO2 Chemical Fixation

“…As the pH approached to neutral, the etching process terminated automatically since the free protons were consumed by 2‐methylimidazole released from ZnCo‐ZIF. Thereupon, ZnCo‐ZIF could be adequately dissolved in part without severe structure destruction, which was further confirmed by the FT‐IR spectroscopy in Figure b. The characteristic bands of ZIF crystals (i.e.…”

“…The shells were also destroyed to some extent (Figure S5a). That is, etching in polymaleic acid occurred not only inside ZnCo‐ZIF but also on the external surface of crystal . Obviously, the etching behaviors in polymaleic acid was substantially different from that in tannic acid.…”

Surfactant-assisted ZnO processing as a versatile route to ZIF composites and hollow architectures with enhanced dye adsorption

“…( Figure S39) This is analogous to the acid-induced etching of Prussian Blue mesocrystals, where adsorbed layers of PVP significantly reduce the rate of etching on the outer surface leading to the controlled formation of hollow particles 29 , and the PVPstabilised template-free formation of MOF-5 derived hollow nanocages. 30 Further, the surface-functionalisation assisted etching of ZIF-8 using phenolic acids has recently been demonstrated 31 .…”

Hierarchical Porous N‐doped Carbon Nanofibers Supported Fe3C/Fe Nanoparticles as Efficient Oxygen Electrocatalysts for Zn−Air Batteries

“…The corresponding TEM image (Figure f) further demonstrated that macrosized voids derived from ZIF‐8 nanoparticles were uniformly distributed over the whole nanofiber. It has been reported that the core of ZIFs could be etched by penetrated free H + ions of TA in weak alkaline and their original framework could remain intact . Following coordination with Fe 3+ , tannin–iron–framework nanoparticles were uniformly covered on the surface of PAN/ZIF‐8 with 8.29 wt % Fe successfully obtained (Figure S2).…”