Defect engineering-induced porosity in graphene quantum dots embedded metal-organic frameworks for enhanced benzene and toluene adsorption

The emerging environmental issues necessitate the engineering of novel and well-designed nanoadsorbents for advanced separation and purification applications. Despite recent advances, the facile synthesis of hierarchical micro-mesoporous metal-organic frameworks (MOFs) with tuned structures has remained a challenge. Herein, we report a simple defect engineering approach to manipulate the framework, induce mesoporosity, and crease large pore volumes in MIL-101(Cr) by embedding graphene quantum dots (GQDs) during its self-assembly process. For instance, MIL-101@GQD-3 (V-meso: 0.68 and V-tot: 1.87 cm(3)/g) exhibited 300.0% and 53.3% more meso and total pore volume compared to those of the conventional MIL-101 (V-meso: 0.17 and V-tot: 1.22 cm(3)/g), respectively, resulting in 1.7 and 2.8 times greater benzene and toluene loading at 1 bar and 25 degrees C. In addition, we found that MIL-101@GQD-3 retained its superiority over a wide range of VOC concentrations and operating temperature (25-55 degrees C) with great cyclic capacity and energy-efficient regeneration. Considering the simplicity of the adopted technique to induce mesoporosity and tune the nanoporous structure of MOFs, the presented GQD incorporation technique is expected to provide a new pathway for the facile synthesis of advanced materials for environmental applications.

Automated summary

The defect engineering approach of embedding graphene quantum dots during self-assembly can manipulate framework, induce mesoporosity, and increase pore volume in MIL-101(Cr), resulting in enhanced adsorption performance.