Yes / In this study, we prepared chitosan (Cs_P) nanofibers (NFs) membrane by electrospinning. The Cs_P NFs membrane was then chemically functionalized (CsF) by a novel stepwise chemical process. The CsF NFs membrane was electrospray with TiO2 nanoparticles (NPs) to prepare the CsF_Coa NFs membrane. A second NFs membrane with embedded TiO2 NPs (Cs_Co) was also prepared by electrospinning. The TiO2 NPs, Cs_P, CsF s, CsF_Coa NFs, and Cs_Co NFs membranes were analyzed by standard spectroscopic, microscopic, X-ray, and thermal methods. Fourier transform infrared (FTIR) analysis confirmed the incorporation of the new functional group into the Cs structure. X-ray photoelectron spectroscopy (XPS) data confirmed the FTIR results and the fabrication of the CsF NFs membrane. Scanning electron microscope (SEM) micrographs showed a smooth morphology for the Cs_P NFs membrane and a denser morphology for the CsF NFs membrane (NFs swelled with functionalization). The SEM micrographs also showed a dense cloud of TiO2 NPs on the surface of the Cs_Coa NFs membrane. Transmission electron microscope (TEM) showed that the particle size of TiO2 NPs varied between 20 and 35 nm and tended to be spherical. The X-ray diffraction (XRD) pattern confirmed the existence of the anatase phase of the TiO2 NPs. The presence of TiO2 in the Cs_Coa and Cs_Co NFs membranes was also confirmed by energy-dispersive x-ray spectroscopy (EDX). Surface profilometry confirmed an increase in the surface roughness of the CsF and Cs_Coa NFs membranes. Brunauer–Emmett–Teller (BET) analysis revealed that the isotherms and hystereses for all NFs membranes were of the IV and H3 types, respectively, corresponding to mesopores and slit pores. The higher photocatalytic activity of the Cs_Coa NFs membrane (89%) compared to the Cs_Co NFs membrane (40%) was attributed to a balance between the short band gap, high surface roughness, and lower surface area.

Yes / In this study, polyacrylonitrile (PAN_P) nanofibers (NFs) were fabricated by electrospinning. The PAN_P NFs membrane was functionalized with diethylenetriamine to prepare a functionalized polyacrylonitrile (PAN_F) NFs membrane. TiO2 nanoparticles (NPs) synthesized in the laboratory were anchored to the surface of the PAN_F NFs membrane by electrospray to prepare a TiO2 NPs coated NFs membrane (PAN_Coa). A second TiO2/PAN_P composite membrane (PAN_Co) was prepared by embedding TiO2 NPs into the PAN_P NFs by electrospinning. The membranes were characterized by microscopic, spectroscopic and X-ray techniques. Scanning electron micrographs (SEM) revealed smooth morphologies for PAN_P and PAN_F NFs membranes and a dense cloud of TiO2 NPs on the surface of PAN_Coa NFs membrane. The attenuated total reflectance in the infrared (ATR-IR) proved the addition of the new amine functionality to the chemical structure of PAN. Transmission electron microscope images (TEM) revealed spherical TiO2 NPs with sizes between 18 and 32 nm. X-ray powder diffraction (XRD) patterns and energy dispersive X-ray spectroscopy (EDX) confirmed the existence of the anatase phase of TiO2. Surface profilometry da-ta showed increased surface roughness for the PAN_F and PAN_Coa NFs membranes. The adsorption-desorption isotherms and hysteresis loops for all NFs membranes followed the IV -isotherm and the H3 -hysteresis loop, corresponding to mesoporous and slit pores, respectively. The photocatalytic activities of PAN_Coa and PAN_Co NFs membranes against methyl orange dye degradation were evaluated and compared with those of bare TiO2 NPs.The higher photocatalytic activity of PAN_Coa membrane (92%, 20 ppm) compared to (PAN_Co) NFs membrane (41.64%, 20 ppm) and bare TiO2 (49.60%, 20 ppm) was attributed to the synergy between adsorption, lower band gap, high surface roughness and surface area.