Electrospinning of polyacrylonitrile nanofibers embedded with zero-valent iron and cerium oxide nanoparticles, as Cr (VI) adsorbents for water treatment

Abstract

Zero-valent iron (ZVI) and cerium oxide (CeO2) nanoparticles (NPs) embedded in polyacrylonitrile nanofibers (NFs) were obtained via electrospinning. Each NF was characterized using Fourier transform infrared spectroscopy and X-ray diffraction. The scaffold morphology and average diameter of the NFs were determined using scanning electron microscopy (SEM). Energy dispersive X-ray spectroscopy (EDS) mapping and Raman spectroscopy were used to characterize the NPs dispersion in the NFs. The Cr (VI) removal efficiency (%E) of ZVI and CeO2 NPs was compared with the efficiency of their corresponding NFs. CeO2 NPs showed 79% Cr(VI) removal; the efficiency was better for their NFs (96%). Regeneration of ZVI NFs was 98 %E. ZVI NPs were the best adsorbent with 99.9% efficiency. An adsorption mechanism was proposed using Langmuir, Freundlich, and Temkin isotherm models. SEM–EDS analyses revealed that Cr adsorbed on the NP and NF surfaces