Tuning inter-layer spacing of graphene oxide laminates with solvent green to enhance its nanofiltration performance

In this study, the inter-layer spacing between graphene oxide (GO) layers were tuned with solvent green (SG) to enhance the nanofiltration performance of the laminar GO membranes. GO nanosheets were firstly modified by SG through the strong π-π stacking interactions. The SG@GO nanocomposites were then assembled onto the surface of tubular ceramic substrate through immersion method. The morphologies and structures of the resulting SG@GO composite membranes were characterized by scanning electron microscope (SEM), energy dispersive X-ray spectrometer (EDX), X-ray diffraction (XRD), and Fourier transform infrared (FTIR). The composite membrane was used for removing dye molecules (Eriochrome black T) from water. It was found from the results that the SG@GO composite membranes showed a flux of 330 L m−2 h−1 MPa−1, which was nearly 6-fold enhancement compared with that of the pristine GO membrane (56 L m−2 h−1 MPa−1), without sacrificing the dye rejection. Therefore, this strategy may provide a facile approach to tune the inter-layer spacing of GO laminates for efficient molecular separation.