Facile Fabrication of Carbon Hybrid Membranes by Fast Self-Assembled Coating with Metal–Phenolic Networks for the Selective Separation of Lead from Water

Inert surface chemistry of carbon materials hinders their flexibility in modification for environmental remediation. Herein, the green facile surface coating of metal–phenolic networks on activated carbon via rapid self-assembly is reported for selective separation of Pb(II) from water. The resulting hybrid membrane (CTA–Zr) demonstrates excellent mechanical stability and water flux at a mass ratio of 80% activated carbon and 20% TA–Zr. Data indicate that Pb(II) adsorption of CTA–Zr is up to 592.75 mg in TA–Zr content and a superior selectivity with a distribution coefficient (Kd) of 55.11 L·g–1 with regard to Pb(II), exceeding that of the ion exchanger D001 by 226 times. Underlying adsorption mechanism is mainly dominated by proton exchange between Pb(II) and phenolic hydroxyl groups of TA as indicated by X-ray photoelectron spectroscopy analysis. Continuous filtration experiments demonstrate that 2850 L of water per square meter of a membrane can be treated using CTA–Zr with a breakthrough point of 1.0 mg·L–1, whereas D001 membrane yields 100 L of clean water. Saturated CTA–Zr can be regenerated more than five times without a considerable decline in performance. This study introduces a novel chemical modification approach for the inert interface to enhance heavy metals removal from water