In Situ Utilization of Residual Ni/Co/Mn in Spent Graphite: Defect‐Engineered Fabrication of rSGO‐NiCoMn Toward High‐Efficiency Antibiotic Degradation Via Peroxymonosulfate Activation

ABSTRACT

The rapid development of the lithium‐ion battery industry produces large quantities of spent graphite anodes. Spent graphite contains abundant intrinsic defects, and residual Ni, Co, and Mn impurities still persist even after intensive purification, resulting in low utilization efficiency and poor economic benefits for traditional graphite recycling. Herein, this work proposes a defect‐engineered upcycling strategy to in situ utilization of residual impurities on waste graphite and fabricate trimetallic‐anchored reduced graphene oxide catalysts (rSGO‐NiCoMn) for tetracycline (TC) degradation by peroxymonosulfate activation. Defect sites of spent graphite can effectively anchor the metal ions. Benefiting from the synergistic redox effect between metal active sites and defective carbon skeletons, the catalyst can effectively degrade TC, with sulfate and hydroxyl radicals as the dominant active species. The catalyst displays broad pH adaptability, excellent water matrix anti‐interference ability, and favorable cycling stability. Life cycle assessment demonstrates that compared with traditional graphite regeneration technologies, this process greatly reduces the energy consumption, water consumption and greenhouse gas emission, with increased economic benefits. Without thorough impurity removal, this strategy enables synchronous resource utilization of carbon substrates and transition metals, providing sustainable candidate toward green recycling of waste graphite and efficient antibiotic wastewater treatment.