Innovative aryl-based hydrophobic deep eutectic solvent for efficient removal of dyes and nanoplastics

Efficient absorption is a highly important strategy to remove environmental pollutants (i.e., dyes and nano plastics), which relays on the development of innovative and sustainable absorbents. Herein, we designed an innovative aryl-based deep eutectic solvent (DES) using diphenylamine (DPA) and benzophenone (BZP) as the component at a molar ratio of 1:1, and this novel DES was denoted as DPA:BZP-1:1. The developed DPA:BZP-1:1 could efficiently adsorb RhB and PS nanoparticles from their aqueous solution/suspension, and the absorption efficiency could reach up to 97.3% and 80%, respectively. Notably, DPA:BZP-1:1 showed a higher absorption efficiency than commercial activated carbon. Experimental and computational results revealed that hydrogen bonding and 7C-7C stacking synergistically contributed to the excellent absorption ability of DPA:BZP-1:1 on dye Rhodamine B (RhB) and polystyrene (PS) nanoplastics. To the best our knowledge, this is the first study on efficient absorption of dye and nanoplastics by aryl-based DESs.