Porous carbon membrane with enhanced selectivity and antifouling capability for water treatment under electrochemical assistance

Abstract

Membrane filtration is an effective method for eliminating contaminants from water, but its performance is restricted by the trade-off between permeability and selectivity, as well as the serious membrane fouling. In this work, a novel porous carbon membrane (PCM) was constructed by coating porous carbon derived from metal-organic frameworks on ceramic membrane support. The PCM possessed good electrical conductivity, large surface area and hierarchical porous structure, making it promising to couple membrane filtration with electrochemistry for improved water treatment. Under electrochemical assistance, the PCM displayed enhanced selectivity and antifouling capability towards the water treatment. At −1.5 V, the PCM showed enhanced removal and reduced flux loss for the removal of suspended particles with size comparable to membrane pore size. Moreover, the PCM under +1.5 V exhibited effective removal of the organic chemicals unfavorable for size-exclusion by the membrane, whose removal efficiencies towards phenol and methyl orange were 3.0 and 3.3 times higher than those without voltage supply, respectively. The PCM with electrochemical assistance also displayed superior performance than PCM alone in real water treatment. The outstanding performance of the PCM under electrochemical assistance was mainly owing to its large electro-active surface area and enhanced mass transfer rate.