Iron doped nanostructured TiO2 for photoelectrochemical generation of hydrogen

This paper describes the photoelectrochemical studies on nanostructured iron doped titanium dioxide (TiO2) thin films prepared by sol-gel spin coating method. Thin films were characterized by X-ray diffraction, Raman spectroscopy, spectral absorbance, atomic force microscopy and photoelectrochemical (PEC) measurements. XRD study shows that the films were polycrystalline with the photoactive anatase phase of TiO2. Doping of Fe in TiO2 resulted in a shift of absorption edge towards the visible region of solar spectrum. The observed bandgap energy decreased from 3.3 to 2.89 eV on increasing the doping concentration upto 0.2 at.% Fe. 0.2 at.% Fe doped TiO2 exhibited the highest photocurrent density, ∼0.92 mA/cm2 at zero external bias. Flatband potential and donor density determined from the Mott–Schottky plots were found to vary with doping concentration from −0.54 to −0.92 V/SCE and 1.7 × 1019 to 4.3 × 1019 cm−3, respectively.