Covalent triazine frameworks composite membrane (CdS/CTF-1) with enhanced photocatalytic in-situ cleaning and disinfection properties for sustainable separation

Abstract

Photo-assisted catalysis is proposed to be an effective approach to deal with the membrane fouling issue, which restricts the broad application of burgeoning 2D covalent organic frameworks (COF) membranes in sustainable separation process. In this work, a new type of [0D + 2D] composite membrane was developed via covalent triazine frameworks (CTF-1) nanosheets with built-in CdS quantum dots (QDs). The regular skeleton of 2D-CTF-1 facilitated the uniform growth of CdS QDs (3 nm) on the planar nanosheets. CdS/CTF-1 composite membrane exhibits high water flux (>170 L m −2 h −1 , 0.1 MPa) and high dyes rejection (>94%) via manipulating transportation channels. More importantly, the built-in [0D + 2D]-heterojunction significantly improves the photocatalytic in - situ cleaning and disinfection performance of CdS/CTF-1 membrane, allowing for regenerating permeability (>95%) with the assist of H 2 O 2 during multiple operations. Thus, we provide a prospective strategy to resolve the membrane fouling issues and enable the practical application of 2D membranes for continuous separation. Photocatalytic in - situ cleaning CdS/CTF-1 composite membrane achieves efficient and continuous separation. • We literally resolve the fouling issue of 2D COF membranes for sustainable separation. • A novel [0D + 2D] membrane was developed by embedding CdS QDs in CTF-1 nanosheets. • CdS/CTF-1 membrane shows improved permeability due to additional channels. • CdS QDs enhance the photocatalytic in - situ cleaning and disinfection performance. • CdS/CTF-1 membrane regenerates its permeability >95% via sunlight illumination.