Graphene Oxide Composite Membranes for Water Purification

Graphene oxide (GO) has attracted remarkable attention as a potential material in the fabrication of next-generation membranes with high water permeability and efficient purification. Herein, an easy and effective means of modifying GO lamellar with a phytic acid (PhA) molecule as both an inserter and a surface modifier was developed to fabricate high-performance GO-based membranes. As a result, the addition of PhA to the GO membrane enhanced hydrophilicity and enlarged the interlamellar spacing. The optimal GP-10 composite membrane displayed a high average pure water flux of 6.31 L m(-2) h(-1) bar(-1) under an ultralow pressure nanofiltration condition, which was about 18.6 times higher than that of 0.34 L m(-2) h(-1) bar(-1) for pure GO membrane. At the same time, it possessed the ability to reject different charged dye molecules with a rejection rate higher than 99.88%. In addition, the composite membrane also showed good structural stability under different pH conditions. This study not only provides a method to simply design GO-based membranes by introducing multifunctional small molecules but also sheds light on using such GO composite membranes in practical water separation applications.

Automated summary

This study developed a method to modify graphene oxide (GO) membranes by adding phytic acid (PhA), which improved hydrophilicity and enlarged interlamellar spacing. The resulting composite membrane showed high water permeability, rejection rate, and structural stability. This research provides insights into the design and application of GO-based membranes for water separation.