Rapid solute transfer photocatalytic membrane: The combination of host–guest interaction and photocatalyst load

Abstract

Separation of dyes and salts from textile wastewater is essential for the secondary utilization of resources. Here in, with supramolecular β-cyclodextrin (β-CD) and mussel-inspired polydopamine (pDA) as building blocks, an super-selectiveand highly water permeable photocatalytic membrane with a stable intermediate layer of AgBr-Ag3PO4 photocatalyst was developed by in-situ formation of AgBr-Ag3PO4 photocatalyst via in-situ formation, in which the β-CD with an inherent cavity was used to formed honeycomb microstructures via host–guest interaction with pDA. The optimized photocatalytic membrane, demonstrated a superior-separation performance with a water permeance of 101.3 LMH bar−1, while achieved a high rejection of all tested dyes of up to 99% and high salt transport of from synthetic dyes textile wastewater. Under visible light, the AgBr-Ag3PO4 layer exhibited ∼ 100% degradation of dyes attaching on the membrane surface, endowing the membrane with excellent photocatalytic self-cleaning ability. Combining with material and membrane characterization, the separation performance of the membrane was rationalized, demonstrating the advantages of the host–guest interaction between β-CD and pDA and in-situ photocatalytic functionalization. This study guides the rapid separation of angstrom-sized molecules in the membrane separation process.