Two-dimensional clay mineral nanomaterial-assisted preparation of MOF-based porous liquids with high-performance for CO₂ selective separation

Porous liquids (PLs) are a new class of materials that combines the permanent cavities of porous solids with the fluidity of liquids. Among them, type I PLs have attracted significant attention due to their inherent permanent porosity and exceptional structural stability. However, conventional synthesis methodologies for PLs exhibit critical limitations. Currently, most studies directly interact pore generators with sterically hindered solvents, which may lead to potential loss of permanent porosity or sorption sites within pores, thereby compromising gas sorption and separation performance. Additionally, the utilization of costly oligomers restricts further scale-up for engineering applications. Herein, we propose an approach for preparing type I PLs employing naturally abundant and cost-effective two-dimensional vermiculite nanosheet materials (VNMs) as carriers of UiO-66 pore generators. Next, this approach effectively preserves sorption sites and pore architectures through grafting site translocation of pore generators. Furthermore, the CO₂ sorption and separation performance of a series of constructed VNMs@UiO-66 PLs was evaluated. Notably, VNMs@UiO-66-100% PLs demonstrate significantly optimized structural properties, exhibiting high oligomer grafting efficiency (58.18%), low viscosity (6.83 Pa s), and superior CO₂ sorption capacity (0.47 mmol g⁻¹), surpassing both pristine UiO-66-OH PLs and VNMs-pure PLs. Meanwhile, these PLs show immense potential for CO₂/N₂ separation applications. More importantly, this strategy not only provides a promising advancement in PL synthesis but also offers new insights for its applications in gas separation.