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

Abstract

a Metal oxides can be used as hard sacrificial templates for the preparation of multifunctional core-shell MOF-based composites following reaction with the organic linker. This is a facile method, but often structures of well-defined shape are only obtained under narrow ranges of conditions, the shape can be lost completely and low levels of MOF conversion observed. Using the prototypical framework ZIF-8 we present an alternative surfactant-assisted surface passivation strategy where the ZnO precursor particles are first coated with a guanidinium-based amphiphile. The surfactant interacts strongly with the oxide surface and allows fine-tuning of the release of Zn(II) and ZIF-8 nucleation by the level of surface coverage permitting a range of well-defined ZnO@ZIF-8 core-shell architectures to be prepared including in water. Further, selective base-etching of the oxide core provides facile access to hollow ZIF-8 and yolk-shell structures. We also demonstrate enhanced dye adsorption and recovery from aqueous mixtures using ZnO@ZIF-8 composite microspheres..

Zeolitic imidazolate framework-8 nanoparticle: a promising adsorbent for effective fluoride removal from aqueous solution

“…This further confirms the core shell structure microspheres shown in Fig. 4b, c (El-Hankari et al 2016).…”

In situ assembled ZIF superstructures via an emulsion-free soft-templating approach

“…10 To date, shaped metal oxides and orderly arranged polymeric/ biomolecule templates have been successfully used as hard templates for the fabrication of complex MOF superstructures. [11][12][13] On the other hand, emulsied droplets and micellar templates have emerged as so templates [14][15][16][17][18][19][20][21][22][23][24] where MOF colloidosomes are produced by mixing immiscible solutions or by controlling the ow of immiscible uids in a microuidic setup. [1][2][3][4][5] The porosity of colloidosomes is dened by the size of the interstices between the colloidal particles which can be tuned by the corresponding particle size.…”

A Fenton-like method using ZnO doped MIL-88A for degradation of methylene blue dyes

“…MOFs, promising catalysts for dye wastewater treatment, have attracted considerable attention for their potential applications in catalysis. [23][24][25] Li et al 26 reported a mesoporous uranium-based metal-organic framework and this material ultimately giving rise to the lowest-density MOF reported to date. Rimoldi et al 27 discussed some representative examples of replacing ZrMOFs with active materials.…”