Degradation of an imidazolium-based ionic liquid in water using monopersulfate catalyzed by Dahlia flower-like cobalt oxide.

[Display omitted] • Dahlia flower-like Co 3 O 4 (DFCoO) is fabricated and comprised of nano-filaments. • DFCoO shows an activity than Co 3 O 4 NP to activate MPS for degrading BMIM. • DFCoO is also reusable for activating MPS to degrade BMIM over 5 cycles. • BMIM degradation mechanism by DFCoO + MPS is elucidated by radical species. • Degradation pathway by this DFCoO + MPS is also revealed by intermediates. As the imidazolium-based ionic liquid (IL), 1-Butyl-3-methylimidazolium chloride (BMIMCl), is increasingly employed in various applications, release of BMIM cation into the environment has posed serious threats on aquatic ecology. Thus, it is imperative to eliminate BMIM from water, and, among various techniques for eliminating BMIM, chemical oxidation is the most effective technique. Nevertheless, studies of using SO 4 −-based chemical oxidation methods for degrading BMIM are still very limited; thus this study aims to develop an effective SO 4 −-based chemical oxidation process for degrading BMIM. As monopersulfate (MPS) is employed as a source of SO 4 −, a special cobalt (Co)-based catalyst is proposed and developed here by fabricating Co 3 O 4 into a unique Dahlia flower-like morphology. Such a Dahlia flower-like Co 3 O 4 (DFCoO) not only can exhibit the flower configuration, but also its floral petal components can consist of many filament-like Co 3 O 4 nanostructures, making this DFCoO possess several advantageous properties over the conventional Co 3 O 4 nanoparticle (NP), including higher redox activity, more reactive surface, higher surface area and larger pore volume. Thus, DFCoO shows a much higher catalytic activity than Co 3 O 4 NP to activate MPS for degrading BMIM. A higher MPS dosage and reaction temperature also enhance BMIM degradation by DFCoO + MPS. DFCoO is reusable for activating MPS to degrade BMIM over multiple cycles. BMIM degradation mechanism and pathway by this DFCoO + MPS is also elucidated by identifying radical species and degradation intermediates. The findings of this study offer an useful approach for developing an advantageous catalyst for sulfate-based degradation of BMIMCl. [ABSTRACT FROM AUTHOR]