Robust electrospinning cellulose acetate@TiO2 ultrafine fibers for dyeing water treatment by photocatalytic reactions

Abstract

Cellulose acetate (CA) composite ultrafine fibers containing different TiO₂ nanoparticle (NP) contents were synthesized via electrospinning for effective dyeing water treatment. Morphology, chemical composition, microstructure, thermal properties and photocatalytic degradation efficiency of the fabricated composite ultrafine fibers were investigated. Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) images revealed that TiO₂ NPs were evenly dispersed on or into the composite ultrafine fibers and the distribution became denser as the concentration of TiO₂ NPs increased. This was also confirmed by Energy Dispersive Spectrometry (EDS), X-ray diffraction (XRD) and Fourier Transform Infrared Spectrometry (FTIR) analyses. Moreover, the results of XRD showed that the crystal structure of the TiO₂ NPs was tetragonal anatase and the TiO₂ NPs enhanced the amorphous phase of the electrospun composite ultrafine fibers. FTIR indicated that the introduction of TiO₂ did not affect the hydrophilic properties of CA and some interaction took place between CA and TiO₂. Thermal gravimetric (TG) analysis showed that the addition of TiO₂ improved the thermal stability of the CA ultrafine fibers, and a higher thermal stability could be achieved with a higher TiO₂ content. Photocatalytic degradation of the dye showed that a higher reaction constant of the photocatalytic degradation of the dye could be obtained with a higher TiO₂ content, with a degradation efficiency of the CA composite ultrafine fibers with 5 wt% TiO₂ as high as 90% after 240 min degradation. The composite ultrafine fibers were effective for cycling use in dyeing water treatment.