Photocatalytic reduction of hexavalent chromium ions from aqueous solutions using polymeric microfibers surface modified with ZnO nanoparticles

Abstract

In this research work, the coaxial electrospinning technique was used for the development of composite membranes based on poly(acrylonitrile-butadiene-styrene)/polyacrylonitrile (ABS/PAN) micrometer fibers loaded with ZnO nanoparticles (NpZnO) in order to evaluate their efficiency in the photoreduction of Cr VI ions in aqueous solutions. The morphological analysis of the fibers was carried out by means of scanning electron microscopy (SEM), the chemical composition of the materials was determined by Fourier transformed infrared spectroscopy (FTIR) with attenuated total reflectance (ATR), the crystallinity of the nanoparticles in the fibrous materials was analyzed by X-ray diffraction (XRD) and the residual Cr VI concentration was measured with the Nesslerizations method. It was demonstrated that by means of the electrospinning technique it is possible to manufacture coaxial fibers based on ABS/PAN with homogeneous morphology with mean diameters of 1.1 µm. Furthermore, through this technique it was possible to obtain ABS/PAN-NpZnO composite coaxial fibers with concentrations of 15, 25 and 30 wt.% of NpZnO, thus favoring the increase in the dose of the photocatalyst. The maximum efficiency of said membrane was obtained with 30 % wt.% of NpZnO with respect to the total solid, allowing the reduction of Cr VI to 81.59 % after 8 h with a substrate concentration of 50 mg/l. Therefore, ABS/PAN-NpZnO fibers are promising candidates for applications related to environmental remediation, such as water regeneration filters, thus partially contributing to the development of sustainable technologies.