Evaluation of Iron oxide decorated on graphene oxide (FE3O4/GO) nanohybrid incorporated in PSF membrane at different molar ratios for Congo red rejection

Abstract

In this study, iron oxide decorated graphene oxide (Fe3O4/GO) with three different molar ratio of Fe decorated on GO nanoplates (Fe percentage: 5 wt%, 10wt%, 20 wt%) were synthesized. First, GO nanoplates were synthesized using natural graphite powder according to the Hummers method. Fe3O4/GO nanohybrid was then prepared by co-precipitation of FeCl3.6H2O and FeSO4.7H2O with GO in the presence of ammonia hydroxide (NH4OH). The nanohybrid was characterized using X-ray diffraction (XRD) and Transmission Electron Microscopy (TEM). The polysulfone (PSf) mixed matrix membranes containing 0.4 wt% of the nanohybrid were prepared by phase inversion method. The effect of different molar ratio of Fe3O4/GO nanohybrid on the membrane morphology was examined by several approaches such as porosity & pore size analysis, contact angle, and Field Emission Scanning Electron Microscopy (FESEM) & Energy Dispersive X-Ray (EDX). The mixed-matrix membranes performance were evaluated by measuring the membrane permeate flux and Congo Red (CR) rejection. All the PSf-Fe3O4/GO mixed-matrix membrane showed enhanced hydrophilicity, permeate flux and CR rejection compared to the neat PSf membrane. Experiment showed that the PSf-Fe3O4/GO mixed-matrix membrane with 5 wt% of Fe decorated onto GO nanoplates was having the best performance with the highest permeate flux of 112.47 L/m2.h and the CR rejection of 97±2%.