Facile fabrication of hierarchical porous ZIF-8 for enhanced adsorption of antibiotics

Aiming for improve mass transfer rate of antibiotics adsorption from water, a strategy of building larger pores (>2 nm) in microporous MOFs has been put forward. However, most of reported approaches are complicated and inefficient. Herein, a facile one-spot approach to fabricate hierarchical porous Zeolitic Imidazolate Framework-8 (HpZIF-8) was developed, where poly(diallyldimethylammonium chloride) (PDDA) was selected as structure-directing agent to modulate the growth of microporous ZIF-8 (mZIF-8). The final products with meso- and macropores exhibit hierarchical porosity. The mechanism was a two-step process: First, crystal nucleus aggregated initiated by electrostatic interaction between cationic PDDA and deprotonated 2-MI anions. Second, Ostwald ripening process and orientated growth occurred with further growth of crystals. For removing Tetracycline Hydrochloride (TH) and Chloramphenicol (CP) from water, hierarchical porous HpZIF-8-10(D) (D = 1.0, 1.5, 2.0) showed larger adsorption capacity than mZIF-8-10 despite of decreased BET surface area, which could be attributed to novel hierarchical porous structures. The adsorption kinetics and isotherms of TH and CP by HpZIF-8-10(1.5) were analyzed. The strategy present here may provide new thoughts for designing more abundant MOF structures and further expand their application range.

2D covalent organic frameworks with built-in amide active sites for efficient heterogeneous catalysis

Two new amide functionalized covalent organic frameworks (COFs) were synthesized via a bottom-up strategy and used as heterogeneous catalysts toward Knoevenagel condensation with excellent performance.

Metal Organic Frameworks Based Materials for Heterogeneous Photocatalysis

The increase in environmental pollution due to the excessive use of fossil fuels has prompted the development of alternative and sustainable energy sources. As an abundant and sustainable energy, solar energy represents the most attractive and promising clean energy source for replacing fossil fuels. Metal organic frameworks (MOFs) are easily constructed and can be tailored towards favorable photocatalytic properties in pollution degradation, organic transformations, CO₂ reduction and water splitting. In this review, we first summarize the different roles of MOF materials in the photoredox chemical systems. Then, the typical applications of MOF materials in heterogeneous photocatalysis are discussed in detail. Finally, the challenges and opportunities in this promising field are evaluated.

Three isoreticular MOFs derived from nitrogen-functionalized diisophthalate ligands: exploring the positional effect of nitrogen functional sites on the structural stabilities and selective C2H2/CH4 and CO2/CH4 adsorption properties

The positional effect of nitrogen functional sites on the structural stability and gas adsorption property was explored in a family of ssa-type MOFs.

An unprecedented water stable acylamide-functionalized metal–organic framework for highly efficient CH4/CO2 gas storage/separation and acid–base cooperative catalytic activity

HNUST-8 exhibits water stable, efficient CH₄/CO₂ storage and separation, acid–base cooperative catalytic activity in a tandem deacetalization Knoevenagel densation.

A pair of polymorphous metal–organic frameworks based on an angular diisophthalate linker: synthesis, characterization and gas adsorption properties

A pair of polymorphous MOFs derived from a bent diisophthalate ligand were synthesized by modulating solvothermal conditions, exhibiting comparable gas adsorption properties with respect to C₂H₂, CO₂ and CH₄.