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

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 H2O2 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.

Automated summary

In this study, a novel [0D + 2D] composite membrane was developed by combining covalent triazine frameworks (CTF-1) nanosheets with built-in CdS quantum dots (QDs) to address membrane fouling issues. The composite membrane exhibited high water flux and dye rejection, while the built-in [0D + 2D]-heterojunction significantly improved photocatalytic cleaning and disinfection performance, enabling high permeability regeneration. This work provides a prospective strategy to resolve membrane fouling issues and enable practical application of 2D membranes for continuous separation.