Development of reduced graphene oxide membrane on flat Moroccan ceramic pozzolan support. Application for soluble dyes removal

Abstract A novel reduced graphene oxide composite membrane was successfully prepared on ceramic pozzolan support by chemical grafting and spin-coating method. The graphite was firstly oxidized and exfoliated to form graphene oxide (GO) that was grafted on modified ceramic surface using 3-Glycidoxypropyltrimethoxysilane (GLYMO). Then, the GO layer was thermally treated to obtain reduced graphene oxide (rGO) membrane. The concentration effect of GLYMO grafting agent was studied in the range of 0.01 to 0.1 M in ethanol. The composite membrane was characterized using XRD, FTIR, Contact angle, SEM, EDX, and AFM Techniques. The morphology analysis showed that rGO layer is homogenously adhered on pozzolan support with 2.0 μm ± 0.1 in thickness using 0.05 M of GLYMO. The experimental results indicated that water permeability decreases from 75 to 2 L/m 2 .h.bar when GLYMO concentration is increased from 0.01 to 0.1 M. The prepared membranes were applied for filtration of bromothymol blue, methyl orange and murexide solutions under pressure of 4 bar during 2 h. The membranes showed a good efficiency in rejection of soluble dyes. For membrane prepared with 0.1 M of GLYMO (optimized membrane), experimental values of rejection achieved 94, 93 and 97% for bromothymol blue, methyl orange and murexide respectively.