Enhanced adsorption of naproxen from aquatic environments by ?-cyclodextrin-immobilized reduced graphene oxide

In this study, a one-step hydrothermal method synthesized ?-cyclodextrin-immobilized reduced graphene oxide composite (?-CD/rGO) was employed to remove naproxen from aquatic environments. The ?-CD/rGO had a porous structure with abundant hydroxyl groups, and acetalization between the ?-CD and rGO provided a more stable three-dimensional structure. The maximum equilibrium adsorption capacity of naproxen on ?-CD/rGO at 313 K was 361.85 mg g-1. The adsorption of naproxen onto the ?-CD/rGO fit well with the pseudo-second-order kinetics and the Langmuir adsorption model. The ?H was higher than 40 kJ mol-1, which indicated that this adsorption was chemisorptive and endothermic. Host-guest interaction, hydrogen bonding, and ?-? interactions were uncovered as three main mechanisms involved in binding between naproxen and the ?-CD/rGO. Moreover, used ?-CD/rGO could be regenerated with ethanol, making this an attractive method for naproxen adsorption in aquatic environments.

Automated summary

The study demonstrated that the β-cyclodextrin-immobilized reduced graphene oxide composite exhibited excellent adsorption performance for naproxen in aquatic environments. The adsorption process followed pseudo-second-order kinetics and the Langmuir adsorption model, with main mechanisms involving host-guest interaction, hydrogen bonding, and π-π interactions. Additionally, the composite could be regenerated with ethanol after use.