Single‐Atom Cobalt Species on Curved Hollow Carbon Sphere: Breaking Linear Scaling Relationship Limitations in Electrocatalytic Deactivation of Dilute Antibiotic Pollutants

ABSTRACT Despite maximal atomic efficiency, single‐atom catalysts (SACs) are constrained by linear scaling relationships in electrocatalytic hydrodechlorination (ECHD), a process effective for antibiotic pollutant deactivation yet challenged by multi‐proton /electron transfer and dilute reactant conditions. Herein, a novel cobalt (Co)‐SACs consisting of single‐atom Co anchored on a nitrogen‐doped hollow porous carbon sphere (Co 1 /N‐HCS) is fabricated, which exhibits a remarkable mass activity of 14.1 g FLO g Co −1 at −0.30 V toward florfenicol (FLO, a typical antibiotic pollutant), outperforming Co 1 /carbon black, Co nanoparticles/carbon black, and previously reported catalysts. Mechanistic studies reveal that the unique hollow porous architecture of N‐HCS facilitates fluid dynamic enhancement and localized adsorptive enrichment of dilute FLO, while its curved surface boosts proton transfer at Co 1 through localized electric field enhancement. The dual enhancements enable Co 1 to break the linear scaling relationship limitations. Field tests for Co 1 /N‐HCS in natural lake water demonstrate excellent environmental stability and matrix interference resistance. Furthermore, it could effectively deactivate dilute FLO (5 µmol L −1 ) while suppressing the emergence of antibiotic resistance gene, highlighting its prospect in antibiotic pollution remediation. This study introduces a paradigm‐shifting support architecture to transcend the SACs performance boundary, while pioneering the application of ECHD for antibiotic pollutant remediation.