Cobalt Single‐Atom Catalysts for Ultrafast Sulfamethoxazole Degradation: Unveiling the Chloride‐Ion‐Enhanced Formation of Co(IV)=O

membrane reactor, which sustains high SMX removal under continuous flow with minimal hydraulic loss. Toxicity assays show significantly reduced ecotoxicity of degradation byproducts and confirm the treated effluent's biocompatibility. These findings establish a chloride-augmented oxidation strategy that transforms a common wastewater constituent into a co-promoter, demonstrating a robust, selective, and scalable platform for advanced water purification.