Preparation of GO/GOH/MOFs ternary blend membrane and its application for enhanced dye wastewater purification

Abstract

A graphene oxide (GO)/hydroxylated graphene (GOH)/MOFs porous layered cross-flow membrane was constructed using a simple vacuum filtration method. Bimetallic MOFs (FeCuBDC) was inserted into the GO nanosheets to facilitate the expansion of adjacent GO layers in the aqueous solution, which increased the interlayer spacing of the composite films. Furthermore, successful loading of GOH not only increased the interlayer spacing of the composite membrane but also improved the self-cleaning catalytic degradation effect. The blend membrane was further characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning and transmission electron microscopy (SEM). Loading ratios of FeCuBDC and GOH were optimized and the results showed that the GO0.8/GOH0.2/(FeCuBDC)4 membrane had a water flux 9.5 times higher than GO membrane and 1.43 times higher than GO1/FeCuBDC4 membrane. Importantly, the separation efficiency of the GO0.8/GOH0.2/(FeCuBDC)4 membrane was very high (Rhodamine B(RhB) membrane separation efficiency was 99.98%), and the interception and flux remained almost constant even after seven RhB separation cycles. This membrane can be directly used for the degradation of pollutants through persulfate activation, and showed the high degradation efficiencies of RhB(99.89%) and methylene blue (MB) (99.87%). Overall, the GO/GOH/FeCuBDC porous layered cross-flow membrane exhibited excellent separation performance, stability, and catalytic activity, and can be used as a potential membrane for water purification and environmental protection.