| dc.description.abstract | This study reports the successful synthesis of Zinc(Zn):Iron (Fe) codoped titanium
dioxide (TiO2) nanoparticles (Z:F-T NPs) using the sol–gel method. Various codoping
ratios are employed, with a 5 mol% dopant concentration added to a constant
amount of tetraisopropyl orthotitanate, ethanol, and diethanolamine. This is done
to improve the light absorption efficiency of the photoanode TiO2, which helps to
reduce electron-hole recombination, improve charge carrier abilities, and enhance
its electrical properties. The resulting brown gel is annealed in a muffle furnace at
500 °C for the anatase phase and 800 °C for the rutile phase. The effects of Zn:Fe
codoping are observed in the Fourier transform infrared analysis with the suppression
of characteristic IR vibration. X-ray diffraction (XRD) analysis confirms the
presence of anatase and rutile phases. In the anatase phase, codoping leads to the
appearance of new diffraction peaks and the suppression of others, attributed to Fe
occupying interstitial positions and Zn substituting Ti4þ. The largest crystallite size
of 24.45 nm is observed for the 1:0.5 Z:F-T NPs. Conversely, the same codoping
ratio in the rutile phase shows a reduced crystallite size of 18.28 nm, highlighting
the phase-dependent behavior of structural growth. Ultraviolet–visible spectroscopy
shows a slight increase in the estimated bandgap for both phases. Scanning
electron microscopy analysis collaborates with the XRD findings by revealing dense
and smooth NP surfaces in the anatase phase, while the rutile phase exhibits
minimal morphological changes. Energy-dispersive X-ray confirms the presence of
Zn, O, and Ti in the anatase phase and Zn, Fe, Ti, and O in the rutile phase,
supporting successful dopant incorporation. The study concludes that high Zn
concentration codoped with Fe to TiO2 anatase phase induces lattice distortion
that improves its structural and optical properties, while the stability of the rutile
phase resists structural modifications. | en_US |
