Graphene oxide membranes on a hierarchical elemental carbon-based support

Abstract

Carbon-based materials have been used in water engineering to provide more effective and efficient methods to deliver clean water. Recent research efforts have focused on the implementation of nanoarchitectured carbon molecular sieves in membranes. In this study, a hierarchical carbon membrane (HCM), fully constituted by elemental carbon structures from the carbon fiber mechanical support to the graphene oxide selective layer, was fabricated. The assembled HCM was characterized by a combination of surface science tools, capillary flow porometry, thermogravimetric analysis, and membrane performance evaluation. The HCM was resistant to harsh cleaning with hypochlorite solutions and annealing cycles (similar to ceramic membranes). The HCM permeability and rejection performance were evaluated in a cross-flow setup, which indicated that the membrane operates in a nanofiltration regime, with 85% rejection of sulfate ions and 1.3 LMH-bar permeability. In summary, the results here support the emerging research direction of hierarchical fully elemental carbon membrane materials to enhance the membrane technology toolbox for sustainable water resource reuse and wastewater reclamation.