High Methylene Blue Adsorption Efficiency of Cellulose Acetate-Based Electrospun Nanofiber Membranes Modified with Graphene Oxide and Zeolite

In this work, cellulose acetate (CA)-based nanofiber membranes were successfully fabricated via an electrospinning method in which sodium dodecyl sulfate (SDS)-graphene oxide (GO) and zeolite were used as additives. The incorporation of SDS-GO and zeolite into CA clearly affects the properties and performance of the fabricated nanofiber membranes, including their morphology, structure, surface area, porosity, and adsorption capacity and efficiency. Some optimization methods, such as the effect of adsorbent material, adsorption process time, and adsorbent dosage, were also investigated. Based on the results of the adsorption studies, the CA/SDS-GO/zeolite membrane exhibited a high methylene blue (MB) adsorption efficiency percentage (94.70%) and an adsorption capacity of 236.76 mg/g after 2 h of adsorption utilizing a small amount of adsorbent (0.005 g). Further adsorption isotherm studies for MB dye showed that it was better fitted by the Freundlich model, with a correlation coefficient of 0.8276. Moreover, the adsorption kinetics model for MB dye was better fitted by the pseudo-second-order model, with a correlation coefficient of 0.9999. These results indicate the interaction between the heterogeneous matrix surface on the CA/SDS-GO/zeolite membrane and the adsorbed MB dye molecules. The mechanism of the CA/SDS-GO/zeolite nanofiber membranes for dye adsorption involves electrostatic interactions between the anionic functional groups of GO (C=O and O–H) and cationic MB dyes, significantly enhancing adsorption capacity. Additionally, this capacity is further augmented by the increased surface area and porosity of the membranes, which results from incorporating SDS-GO and zeolite into the composite, allowing for more dye to be adsorbed over longer adsorption times.

Highlights.

CA/SDS-GO/zeolite nanofiber membrane presented good adsorption performance