Few-layer MoS co-assembly with GO to optimize defect channels and stability of GO membranes for high-performance organic-inorganic separation.

The selective separation of organic compounds and inorganic salts is essential for wastewater recycling in fine chemical industries such as pharmaceuticals and pesticides. Membrane separation technology offers a promising solution. However, conventional organic membranes often face challenges related to precise separation and solvent resistance. While graphene oxide (GO) membranes exhibit excellent solvent resistance, their separation performance and structural stability require further improvement. In this study, we developed a GO/few-layer molybdenum disulfide (FLMoS) membrane via co-assembly. The optimized GO/FLMoS membrane demonstrated a water permeability of 28.4 LMH/bar, approximately four times higher than conventional GO membranes, and achieved a separation factor exceeding 900 for organic/inorganic mixtures-among the highest reported for two-dimensional (2D) membranes. Comprehensive characterization, including low-field nuclear magnetic resonance (LF-NMR), revealed that this superior performance was attributed to controlled defect channels, enhanced interlayer cross-linking, and the intrinsic rigidity of FLMoS, which provided high structural stability and minimal swelling. Moreover, mechanical strength assessments, including critical destructive load force and nanoindentation tests, confirmed significant improvement in structural robustness. As a result, the GO/FLMoS membrane maintained stable water permeability and separation efficiency over 100 hours of continuous operation and six chemical cleaning cycles, demonstrating its potential for sustainable wastewater treatment and resource recovery.