UiO-66-SO3H@nylon-6 Membrane for Rapid Adsorption and Removal of Rhodamine B (RhB) from Aqueous Solutions

Widespread dye contamination poses a serious threat to humans and aquatic environments. Metal–organic frameworks (MOFs) with abundant reactive groups and high specific surfaces are candidates for the adsorption of dyes. In this study, good growth of UiO-66-SO3H crystals on the surface of nylon-6 fibers was achieved based on the idea of in situ growth. UiO-66-SO3H with a sulfonic acid group was successfully introduced into nylon-6 electrostatic spinning fiber, and the UiO-66-SO3H@nylon-6 membrane with high specific surface area and a three-dimensional mesh structure was obtained, which effectively solved the problems of clogging of the equipment, difficulty in being separated and recovered from the water, the possible secondary pollution of the water environment caused by the powder form of the MOF material, etc. The UiO-66-SO3H@nylon-6 membrane has a good adsorption capacity for rhodamine B (RhB), and the experimental data are consistent with the pseudo-second-order kinetic model and Langmuir model, which shows that the adsorption is a spontaneous heat absorption process. Pore-filling, hydrogen bonding, π–π interactions, and electrostatic attraction induced by –SO3H are the adsorption mechanisms of RhB on this adsorbent. In conclusion, the UiO-66-SO3H@nylon-6 membrane is an adsorbent capable of rapid adsorption of RhB and can be easily separated from water for recovery, regeneration, and utilization. This study may provide ideas for the application of MOFs in the field of pollutant removal.