High-flux and anti-fouling membrane distillation membrane with VOC capture ability enabled by ZIF-8
Dafei Sheng, Xinlin Li, Xin Huang, Dou Ma, Chao Sun, Yuhao Zhu, Xiaoqi Wang, Zhipeng Wang, Xiao Feng, Shuang Zhao, Bo Wang
Abstract
Seawater desalination and wastewater purification from brackish water, shale gas extraction, and industrial processes remain vital but challenging. Membrane distillation offers a promising solution yet struggles with low flux, membrane fouling, and the permeation of volatile organic compounds alongside water vapor. Here, we introduce an omniphobic ZIF-8 composite membrane that traps volatile organic compounds under vacuum through crystal phase transitions and enhances water evaporation via linkage swing within hydrophobic micropores. This membrane, with a 92% ZIF-8 loading, fabricated through thermally induced phase separation, hot-pressing, and surface coating, can process over 38,000 L of water with 10 ppm contaminants per square meter without needing reactivation. Achieving a normalized flux of 71.8 L m–2 h–1 bar–1, it outperforms conventional membranes by fivefold in treating 10.5 wt% saline water, while maintaining excellent cyclic stability over 900 h and high anti-fouling properties. This work presents an effective approach for sustainable water purification. Seawater desalination and wastewater treatment face challenges like low flux and membrane fouling. Here, authors develop an omniphobic ZIF8 composite membrane that captures volatile organic compounds and enhances water evaporation, achieving high flux and stability for sustainable purification.