Development of polydopamine/Cobalt single atom co-doped Al₂O₃ ceramic membrane: An effective strategy for...

This study addresses deficiencies in the anti-fouling properties and long-term operational stability of ceramic membranes exhibiting excellent oil-water separation performance. Using a combined deposition and low-temperature reduction approach, hydrophilic polydopamine (PDA) and transition metal single-atom cobalt (Co₁) were immobilized onto alumina ceramic membrane surfaces to fabricate a superhydrophilic anti-fouling Al₂O₃ ceramic membrane. The separation performance of this membrane for oil/water emulsions was subsequently systematically investigated. The doping of PDA endows the membrane with remarkably high oil/water separation efficiency (above 99 %) and flux (705.6 ± 34.1 L m^-2·h^-1). In the Ammonium persulfate (APS) system, Co₁, through valence state cycling (Co²⁺/Co³⁺), generate ·OH and SO₄·^- radicals, which promote the free radical chain reaction and endow the membrane with self-cleaning ability. The synergistic molecular interactions within the composite architecture bestow exceptional structural integrity during continuous multiphase separation operations, while establishing innovation in membrane longevity enhancement through energy-barrier elevation against interfacial fouling degradation mechanisms. This work provides a novel strategy for developing anti-fouling membranes with high efficiency in oil-water separation.