Carboxylated nanodiamond-enhanced photocatalytic membranes with improved antifouling and self-cleaning properties

This study reports a novel carboxylated nanodiamond (CND)-enhanced self-cleaning antifouling catalytic membrane. Four poly(vinylidene fluoride) (PVDF)-based membranes (PVDF, P-CND, P-TiO2, and P-CND/TiO2) were fabricated by non-solvent-induced phase separation. The membrane pore size, porosity, hydrophilicity, and permeability were in the same order of: PVDF < P-CND < P-TiO2 < P-CND/TiO2, suggesting that CND and TiO2 had a synergetic effect in improving these parameters. The two membranes containing CNDs (P-CND and P-CND/TiO2) had the highest flux recovery ratios (∼80%) but lowest irreversible fouling ratios (∼20%), indicating that CNDs significantly enhanced the antifouling performance of the membrane. CNDs effectively improved the photodegradation performance of the TiO2 membrane, rendering the catalytic membrane with better self-cleaning properties. This study provides an effective strategy for engineering antifouling, self-cleaning photocatalytic membranes. The engineered catalytic membrane with excellent antifouling and self-cleaning properties could be used for the degradation of various organic contaminants in wastewater treatment and reclamation.