Nanoconfined catalytic membranes assembled by cobalt-functionalized graphitic carbon nitride nanosheets for rapid degradation of pollutants

Abstract

Sulfate radical-based advanced oxidation processes (SR-AOPs) constitute an efficient method for the effective removal of organic pollutants in water bodies. A novel cobalt-functionalized graphitic carbon nitride (Co@g-C3N4) membrane was designed and prepared for the first time to activate peroxymonosulfate (PMS) for pollutant degradation. The prepared Co@g-C3N4 membrane demonstrated a long-term stability over 100 h continuous operation at a flux of 113.2 L∙m−2∙h−1 and a retention time of 33 ms for 100 % removal of ranitidine (5 mg/L) as the target pollutant with the first-order rate constant 4–6 orders of magnitude higher than that in previously reported AOP systems. Singlet oxygen significantly contributed to the degradation of diverse pollutants within the numberless nanoconfined spaces of membrane. Oxygen vacancies in Co@g-C3N4 can effectively promote the redox cycle of ≡Co(II)/ ≡Co(III) to maintain the catalytically active center. The developed membrane herein combining membrane filtration and AOP would provide a novel strategy for water and wastewater treatment.