A cationic metal-organic framework based on {Zn4} cluster for rapid and selective adsorption of dyes

Until now, to remove the harmful organic dyes from effluents is an outstanding challenge. The design and synthesis of new porous materials capable of selectively adsorbing dyes are critical to the environment and human health. Here, a unique cluster-based cationic metal-organic framework, named {[Zn8(BTA)6(L)5Cl2]·(NO3)3}·5DMF (NUM-4) was synthesized, which displays one-dimensional (1D) open channels along a axis in its 3D supramolecular stacking structure. Benefiting from the nature of cationic framework and high surface area/pore volume, NUM-4 shows rapid and selective adsorption of anionic dyes (MO, AO, CR and MB) based on the charge-exclusive effect. Besides, the adsorbed dyes can be easily released in NH4Cl saturated solution of ethanol.