Stable synergistic decontamination and self-cleaning performance of powerful N-rGO catalytic ozonation membrane: Clustering effect of free electrons and role of interface properties

An efficient permeability lossless catalytic ceramic membrane (N-rGO-CM) fabricated from nanoporous nitrogen-doped reduced-graphene-oxide (N-rGO) with tunable interface properties was designed, in which homogeneously embedded highly active doped N gathers free electrons from membrane interface to produce more OH. The resulting degradation rate constant (kobs) toward p-chlorobenzoic-acid/benzotriazole in N-rGO-CM with ozone was 3.95/3.22 times that of the CM with ozone. Results showed that main self-cleaning behavior of N-rGO-CM was in-situ degradation of surface membrane fouling. Increasing thickness and roughness of skin layer synergistically enhanced interfacial catalytic performance of N-rGO-CM, but decreased self-cleaning performance. Increasing hydrophobicity enhanced N-rGO-CM performance, but was correlated with target compound polarity. The designed N-rGO-CM overcame the inhibiting eff ;ect of reactions between radicals and impurities in effluent of WWTPs, and demonstrated exceptional efficiency in removal of ketoaldehydes, the precursors of halogenated hydrocarbons and haloacetic acids. This study will aid the development of carbon-based catalytic membranes for water treatment.