Defect Dominated Hierarchical Ti-Metal-Organic Frameworks via a Linker Competitive Coordination Strategy for Toluene Removal

Constructing a hierarchically porous structure in metal-organic frameworks (MOFs) can improve the accessibility of active sites and facilitate mass diffusion to enhance their adsorption and catalytic efficiency. Here, a novel linker competitive coordination strategy based on the electronegativity difference of two kinds of organic linkers is proposed to tailor the porous structure of Ti-MOF (MIL-125). A series of Ti-MOFs with continuously tunable hierarchical porosity is obtained by simply adjusting the molar ratios of two organic linkers. The demonstration of toluene removal shows that the competitive coordination strategy not only contributes to wide pore size distribution to enhance the adsorption performance of toluene, but also endows good charge separation ability to facilitate photocatalytic performance. Finally, the toluene removal efficiency of optimal Ti-MOF with mixed organic linkers of 1:1 molar ratio is 2.14 times and 1.88 times of the pristine MIL-125 and MIL-125(NH2), respectively. This strategy opens a new prospect to optimize Ti-MOF properties for various heterogeneous catalysis applications.

Automated summary

Constructing a hierarchically porous structure in metal-organic frameworks (MOFs) improves active site accessibility and mass diffusion, enhancing adsorption and catalytic efficiency. A novel linker competitive coordination strategy based on electronegativity difference produces Ti-MOFs with continuously tunable hierarchical porosity, demonstrating improved toluene removal efficiency and photocatalytic performance. This strategy opens new possibilities for optimizing Ti-MOF properties in various catalysis applications.