A Solid‐Solution Strategy for One‐Step Construction of Hierarchically Porous Metal–Organic Frameworks

The construction of hierarchical porosity in metal–organic frameworks (HP‐MOFs) by expanding the pore size to mesopore or even macropore region is important but still challenging. In this work, a facile solid‐solution strategy is proposed here to increase the pore size, giving rise to hierarchically porous MOFs by one‐step activation. It is found that for a microporous M ‐tpa structural platform, the cupric form collapses after activation, while the nickelous one shows the prototypical microporosity. The solid‐solution Ni 2+ /Cu 2+ form is therefore synthesized and is found to show hierarchical porosity after activation. The ratio of mesopore can be modulated by changing the relative concentration of Ni 2+ to Cu 2+ . The effect of coordinative and noncoordinative solvents on the porosity is also investigated. Finally, it is found that the as‐synthesized HP‐MOFs here are able to adsorb bulky neutral and anionic dyes, while excluding cationic dyes, suggesting that the as‐synthesized HP‐MOFs here are probably cationic. It should be noted that the pristine microporous MOF is not able to adsorb the dye.