| Summary: | Synthesis and characterization of Fe-TiO2, N-TiO2, and Fe-N-TiO2 have
been carried out. This research was done to determine the effect of dopant
concentration of 2.5, 5.0, and 7.5% w/w on the band gap energy of TiO2 and the
effect of single and double dopants to the band gap energy of TiO2. All materials
have been synthesized by using impregnation method with TiO2 as precursor,
FeCl3.6H2O salt as Fe3+ ions source, and urea as nitrogen source. All samples
were characterized by using FT-IR spectroscopy, UV-Vis specular reflectance
spectroscopy, and X-ray diffraction.
The results showed that the optimum band gap energy of Fe-TiO2 and
N-TiO2 yielded from the dopant variation were 3.10 and 3.07 eV. Compared to
band gap energy of single doped-TiO2 and pure TiO2, Fe-N-codoped TiO2 had the
smallest band gap energy with the optimum value of 2.96 eV. The presence of
dopant in TiO2 introduced new level energy between valence and conduction
bands of TiO2 so the band gap energy decreased. Fe-N-TiO2 has the smallest band
gap energy due to the synergistic effect of new levels energy above valence band
and below conduction band of TiO2 induced by both of Fe3+ ions and nitrogen.
The presence of dopant into TiO2 not only affect the electronic structure but also
crystalline structure of TiO2. All synthesized materials have lower crystallinity
compared to pure TiO2, where Fe-N-TiO2 has the lowest crystallinity due to the
presence of double dopants in TiO2.
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