Electrospun polyacrylonitrile-Moringa Olifera based nanofibrous bio-sorbent for remediation of Congo red dye

Abstract

The integration of polymers with biomaterials offers promising and effective nanomaterials with intrinsic and extrinsic properties that are utilized in several applications. The present work reported the development of Polyacrylonitrile (PAN) supported biosorbent (Moringa oleifera, (MO)) which was utilized for the removal of Congo red (CR) dye from aqueous solution. MO loaded polyacrylonitrile (PAN/MO) nanofibrous biosorbent was prepared by solvent homogenization method followed by electrospinning for the deposition of nanofibers. The developed nanofibrous biosorbent was investigated by several analytical techniques such as FESEM, TEM, XRD, FTIR, and XPS to study the material properties along with their control counterparts. The adsorption experiments such as the effect of contact time, effect of concentration, effect of pH, and reusability studies were performed. The adsorption capacity of the nanofibrous biosorbent is ∼52 mg g−1, which is significant as bulk sorbent when compared with other activated carbon in powder form. The adsorption capacities vary with an increase in the dye concentration and obtained ∼88% of dye removal. The adsorption data are validated using the empirical pseudo-first-order, pseudo-second-order kinetic models, and the mechanism involved in the adsorption phenomena was investigated by Langmuir and Freundlich isotherm models, respectively. The biosorbent follows the pseudo-second-order kinetics and Freundlich isotherm, which involves in multilayer adsorption phenomena. In a nutshell, the present work corroborated the importance of bio-based natural sorbent available in nature which can be effectively engineered with polymeric materials for obtaining novel hybrid materials to explore their inherent properties for various applications.