3D hierarchical aquaporin-like nanoporous graphene membrane with engineered tripartite nanochannels for efficient oil/water separation

Abstract

The aqueous system is being polluted by the untreated direct discharge of industrial oily wastewater into the ecosystem. Due to its low cost, energy economy, and sustainability, the advanced membrane filtration method is regarded as one of the best methods for treating oily wastewater. Its exceptional atomic thickness and superior amphiphilic properties of graphene oxide (GO) nanosheet make it one of the finest 2D constituents for creating membranes with high permeability. Nevertheless, the interlayer d-spacing of multi-stacked GO membranes is crucial since it is responsible for the permeability/selectivity trade-off. To efficiently separate oil-in-water emulsion using an in-situ polymerization technique, we developed an aquaporin-like 3D hierarchical multi-functionalized nanoporous graphene (NPG) membrane with tripartite nanochannels. The extraordinary, prepared membrane displayed both ultra-water-permeability of 2490 L m−2 h−1.bar along with superior selectivity. Consequently, the permeance of the aquaporin-like 3D hierarchical multi-functionalized NPG membrane achieves a higher flux than the GO membrane, while the oil rejection reaches ~97%.