Ionic liquid gel microspheres as an emerging platform for constructing liquid compartment microreactors

Abstract

Flow chemistry technology innovatively integrates the traditional independent experimental operation processes, speeds up reaction rates and, especially, can be applied in special reactions that are hazardous or under difficult reaction conditions, being beneficial for the development of green chemistry and laboratory automation. In flow chemistry, the application of traditional pipeline microreactors is usually limited by blockage, corrosion and difficult maintenance. The micro/nanomaterials-based microreactors for flow chemistry are supposed to solve these problems. Herein, we report a novel solid–liquid composite microreactor (BiOBr@ILG-microspheres) with ionic liquid compartments based on ionic liquid gel microspheres (ILG-microspheres) and a typical photocatalyst, BiOBr. The BiOBr@ILG-microspheres show high photodegradation performance, which is attributed to the enrichment of organic substrates by the ILG-microspheres, the efficient charge transfer microenvironment of the internal ionic liquids (ILs), and the flower-like heterostructure of the microspheres that hosts abundant active sites. Furthermore, the BiOBr@ILG-microspheres are embedded in a poly(vinyl alcohol) (PVA) hydrogel to build a multi-liquid phase membrane, which exhibits promising performance in removing pollutants continuously from flowing water with an ∼100% removal rate of ciprofloxacin for a long time, due to the synergic effect of the enrichment and catalytic degradation of the pollutants by the BiOBr@ILG-microspheres. This work provides a new research strategy for constructing liquid compartment microreactors with a synergistic effect of extraction–catalysis using the novel developed ILG-microspheres, which will attract widespread interest because it is in accordance with the concept of green chemistry.