This study presents a novel approach to engineering self-cleaning membranes for water treatment. The researchers designed a metal-polyphenol network to direct the formation of catalytic nanofilms ( approximately 18 nm thick) on inert polymeric membranes. This chelation-directed mineralized coating exhibits high polarity, superhydrophilicity, and ultralow adhesion to crude oil, enabling efficient separation of crude oil-in-water emulsions. The in-place flux recovery rate exceeded 99.9%, significantly reducing the need for traditional ex situ cleaning. The chelation-directed nanoarmored membrane showed 48-fold and 6.8-fold figures of merit for in-place self-cleaning regeneration compared to the control membrane and simple hydraulic cleaning, respectively. Density functional theory calculations were used to identify the precursor interaction mechanisms. This method offers promise for sustainable applications in catalysis, biomedicine, environmental remediation, and other fields.This study presents a novel approach to engineering self-cleaning membranes for water treatment. The researchers designed a metal-polyphenol network to direct the formation of catalytic nanofilms ( approximately 18 nm thick) on inert polymeric membranes. This chelation-directed mineralized coating exhibits high polarity, superhydrophilicity, and ultralow adhesion to crude oil, enabling efficient separation of crude oil-in-water emulsions. The in-place flux recovery rate exceeded 99.9%, significantly reducing the need for traditional ex situ cleaning. The chelation-directed nanoarmored membrane showed 48-fold and 6.8-fold figures of merit for in-place self-cleaning regeneration compared to the control membrane and simple hydraulic cleaning, respectively. Density functional theory calculations were used to identify the precursor interaction mechanisms. This method offers promise for sustainable applications in catalysis, biomedicine, environmental remediation, and other fields.