Upcycling spent lithium battery cathodes into efficient PMS catalysts for organic contaminants degradation

The rapid accumulation of spent lithium-ion batteries (SLIBs) poses a global challenge in terms of their disposal and management. Considering the substantial quantity of transition metals contained in SLIBs, the preparation of derived catalysts for environmental remediation has emerged as a promising approach for the recycling of SLIBs. Herein, the citric acid-based sol-gel method was employed to synthesize the catalyst from SLIBs. The derived spent cathode material (LiNixCoyMn1−x-yO2, NCM) composites exhibit superior catalytic activity and display higher adaptability to the environment, effectively removing typical azo dye, methylene blue (MB), as well as various organic contaminants, sulfamethoxazole (SMX), levofloxacin (LVF) and rhodamine B (RhB) in 30 min. The Co2+ and Mn2+ ions in the catalyst play a crucial role in activating PMS to generate 1O2 and O2•−. The degradation of MB proceeds through several reaction pathways, including demethylation, oxidation, and ring-opening reactions, as confirmed by the Fukui function and UPLC-QTOF-MS analyses. The assessment of toxicity in the degradation products was conducted using T.E.S.T. and ECOSAR 2.0. This proposed method can be highly suggested as a promising strategy for the recycling and utilization of SLIBs, transforming them into efficient catalysts for PMS systems in environmental remediation. [Display omitted] ●Spent cathode material-derived catalyst was used to degrade methylene blue by PMS.●The catalytic activity of SG-NCM400 was greatly improved compared to C-NCM.●The redox cycles of Co2 + /Co3 + and Mn2 + /Mn3 + /Mn4 + promoted the production of 1O2 and O2•− by PMS.●Toxicity assessment revealed a low ecotoxicity of most intermediates.●The SG-NCM400/PMS system exhibited great practical potential in water purification.