2D Heterostructure Membranes with Sunlight‐Driven Self‐Cleaning Ability for Highly Efficient Oil–Water Separation

• Published in: Advanced functional materials 2018-03, Vol.28 (13), p.n/a
• Main Authors: Liu, Yanan, Su, Yanlei, Guan, Jingyuan, Cao, Jialin, Zhang, Runnan, He, Mingrui, Gao, Kang, Zhou, Linjie, Jiang, Zhongyi
• Format: Article
• Language: English
• Subjects: 0D/2D heterojunctions; 2D heterostructure membranes; Carbon nitride; Cleaning; Filtration; Flux; graphene oxide nanosheets; Heterojunctions; Interlayers; Materials science; Membranes; Nanostructure; oil/water separation; Penetration; Recovery; Separation; Solar energy; Sunlight; sunlight‐driven self‐cleaning; Titanium dioxide; Water purification
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.201706545

Introducing solar energy into membrane filtration to decrease energy and chemicals consumption represents a promising direction in membrane fields. In this study, a kind of 0D/2D heterojunction is fabricated by depositing biomineralized titanium dioxide (TiO2) nanoparticles with delaminated graphitic carbon nitride (g‐C3N4) nanosheets, and subsequently a kind of 2D heterostructure membrane is fabricated via intercalating g‐C3N4@TiO2 heterojunctions into adjacent graphene oxide (GO) nanosheets by a vacuum‐assisted self‐assembly process. Due to the enlarged interlayer spacing of GO nanosheets, the initial permeation flux of GO/g‐C3N4@TiO2 membrane reaches to 4536 Lm−2 h−1 bar−1, which is more than 40‐fold of GO membranes (101 Lm−2 h−1 bar−1) when utilized for oil/water separation. To solve the sharp permeation flux decline, arising from the adsorption of oil droplets, the a sunlight‐driven self‐cleaning process is followed, maintaining a flux recovery ratio of more than 95% after ten cycles of filtration experiment. The high permeation flux and excellent sunlight‐driven flux recovery of these heterostructure membranes manifest their attractive potential application in water purification. A 2D heterostructure membrane is fabricated via intercalating a g‐C3N4@TiO2 heterojunction into adjacent graphene oxide (GO) nanosheets by a vacuum‐assisted self‐assembly process. The enlarged interlayer spacing of GO nanosheets endows the 2D heterostructure membrane a with high permeation flux, and the photocatalytic activity of g‐C3N4@TiO2 0D/2D heterojunctions endows the 2D heterostructure membrane with self‐cleaning ability for the separation of oil‐in‐water emulsions.