Electrospun polystyrene/graphene oxide fibers applied to the remediation of dye wastewater

Abstract

After preparing composite PSGO films by coating electrospun polystyrene (PS) fibers with graphene oxide (GO), we examined their use as dye adsorbents for water remediation. The GO, which was synthesized via a modified Hummers' method, was adsorbed on the surface of the PS fibers. Through X-ray diffraction (XRD), Fourier Transform Infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermogravimetry (TGA) analyses, we characterized the structure and morphology of the composite films, confirming that the GO was successfully incorporated onto the PS fibers. SEM images revealed that the PS fibers exhibited a smooth surface and that the GO was uniformly deposited on them. TGA analysis indicated that the PSGO is composed of ∼13 wt% GO and ∼87 wt% PS, and that both components exhibited similar thermogravimetric behavior. We examined the removal of the methylene blue (MB) dye from aqueous solutions as a model system to assess the adsorptive properties of the PSGO films. The composite films had a removal capacity that was approximately 2.3 times greater than that of pure PS membranes. For all MB concentrations investigated, the removal of the dye, which was very fast in the first 30 min, the equilibrium value of the adsorption capacity (qe = 114 mg g−1) was reached after 120 min. The kinetics of the adsorption process was best described by the pseudo-second-order (PSO) model, which predicted an adsorption capacity (qt) of 116.69 mg g−1.