Selective adsorption and separation of dyes from aqueous solution by a zirconium‐based porous framework material

A water‐stable zirconium‐based metal–organic framework, MOF‐808, has been applied in selective adsorption and separation of the dyes (anionic fluorescein sodium [FS] and cationic rhodamine B [RhB]). Single‐component adsorption experiments indicate the superior adsorption of FS with a maximum adsorption capacity of 480.2 mg g−1, almost four times of the capacity for RhB. Further separation study shows that separation of these dyes can be achieved at a wide pH range of 3.5–8.5 and continuous separation is feasible in a simulated chromatographic column. Besides, this material can be well regenerated through acid washing method. Pore sieving effect is considered to be the key factor for the highly efficiency separation, and the host–guest interactions including H‐bond, π–π stacking, and coordination interactions are the main driven forces for the adsorption. Thus, this work demonstrates that MOF‐808 not only is a promising material for efficient separation of FS and RhB but also provides a new perspective for developing adsorbent with the help of distinct pore and chemical properties of MOFs. The stable MOF‐808 can separate fluorescein sodium (FS) and rhodamine B (RhB) dyes with an ideal selectivity. The adsorption capacity of MOF‐808 for FS can reach up to a high value of 480.2 mg g−1. Continuous separation can be achieved in a chromatographic column via using MOF‐808 as stationary phase. Pore sieving effect is the main reason for the separation.