Effect of Fe-doping on structural and optical properties of ZnO nanorods

The present study aims to explore the role of Fe-doping in modulating the crystallite growth and structural properties of ZnO nanorods. The ZnO and Fe-doped ZnO nanorods were synthesized using the co-precipitation method, with zinc chloride (ZnCl 2 ) as the precursor, Ferric chloride (FeCl 3 ) as the dopant, and Sodium dodecyl sulfate (SDS) as a capping agent. The characterizations of prepared nanorods were performed using UV-Vis, XRD, FESEM, EDX, TEM, and FTIR spectroscopy. The FTIR characterization observed a peak at 567 cm −1 for ZnO nanorods, which shifted to 528 cm −1 for Fe-doped zinc oxide nanorods. The UV-visible spectra also indicated a red shift in the Fe-doped spectrum of ZnO nanorods. The XRD spectrum, complemented by Rietveld refinement, Williamson-Hall analysis, and electron density mapping, provides complete insight into the crystal structure of ZnO and Fe-doped ZnO nanorods. EDX analysis confirmed the doping of Fe (0.45%) in ZnO nanorods. TEM images exhibit long, rod-shaped ZnO with a diameter of 13 nm, which, on Fe-doping, increased to 18 nm. The optical properties of these nanorods were also investigated using UV-visible spectroscopy to calculate the band potentials, respective band gaps, and Urbach energy, which shows the distortion in the crystal lattice after Fe doping and was also responsible for the reduced band gap. The detailed analysis of the synthesized nanomaterials reveals that Fe-doping in the ZnO lattice reduces the crystallite size, while increasing the lattice parameters and cell volume. The decrease in crystallite size suggests that Fe-ions act as a crystallite growth inhibitor, while maintaining the crystal structure and phase stability. These findings provide crucial insights into the structural modifications and optical behavior of Fe-doped ZnO nanorods, paving the way for their potential applications in photonic and catalytic devices.