Structural, Optical, and Photocatalytic Properties of Zn-Doped NiO Nanofibers for Environmental Applications

In this study, Zn-doped NiO nanofibers (NFs) were prepared using the electrospinning method. These nanostructures were prepared with different zinc concentrations (1, 3, 6, and 12 mol%). Their physical properties were studied by different characterization methods such as XRD, SEM, EDS, PL, and UV-Vis spectroscopies. Also, the electrical properties of these nanostructures were investigated by impedance spectroscopy (IS). The XRD and EDS analysis results showed the formation of the Face-Centered Cubic (FCC) phase of NiO nanofibers and the presence of Ni, Zn, and O in the final product. The morphological studies obtained from SEM images demonstrated that introducing Zn into the NiO lattice has given rise to an increment of nanofibers' diameters. Also, the absorption spectra were measured in the range of 200-900 nm, revealing that they were displaced to lower wavelengths. In addition, Tauc plots showed that the energy band gaps were in the range of 1.63 to 2.12 eV. PhotoLuminescence (PL) spectra indicated that increasing the concentration of Zn caused shifts in emission bands and, as a result, in their intensity. Impedance spectroscopy showed reduced impedance with increasing Zn concentration, enhancing charge separation. Furthermore, photocatalytic experiments for Methylene Blue (MB) degradation revealed that NFs with 12 mol% Zn exhibited the highest degradation efficiency of 96%. These findings suggest that Zn-doping effectively enhances the structural, optical, and photocatalytic properties of NiO NFs, offering the potential for advanced photocatalytic applications.