Chem. Eng. Sci. - Photocatalytic Self-Cleaning Membranes with Amphiphilic Surface for Durable and Stable Oil-Water Separation

Jianghao Bai, Qianqian Lan*, Leyao Liu, Wenlong Liu, Yan Lv, Zhenyu Wang, Tianxi Liu*

Chem. Eng. Sci.2025, DOI: 10.1016/j.ces.2025.121829

Durable and stable oil–water separation appeals for membranes with excellent anti-fouling performances. However, enhanced resistance against both reversible and irreversible foulants is still challenged. Herein, a novel amphiphilicity-photocatalysis synergistic strategy to architect stable oil–water separation membranes is proposed. Membranes are fabricated by stacking bismuth oxychloride/titanium dioxide (BiOCl/TiO2) heterojunction nanosheets on macroporous substrates, followed by surface modification using hydrophilic layer grafted with dispersed hydrophobic chains. The prepared membranes are featured with sphere-decorated amphiphilic surface and internal layered structure. The amphiphilic surface allows the formation of stable hydration layer through hydrophilic domains for blocking oil adhesion and the reduction of surface energy by hydrophobic chains for releasing adsorbed oil. Meanwhile, BiOCl/TiO2 heterojunctions act as photocatalysts for degradation of adhered foulants. Such blocking-releasing-degradation multifunctionality enables the membranes superior oil–water separation efficiency (>98 %) and enhanced anti-fouling performances (flux decline ratio < 45 %, flux recovery ratio > 95 %) for durably separating surfactant-stabilized oil/water emulsions.

Link: https://doi.org/10.1016/j.ces.2025.121829