Enhanced Photoelectrochemical Response of BaTiO3 with Fe Doping: Experiments and First-Principles Analysis

We use a combination of experiments and first-principles density functional theory based calculations in a study of the photoelectrochemical properties of Fe-doped BaTiO 3 nanopowder. BaTiO 3 with 0.5–4.0 atom % Fe doping is synthesized via a polymeric precursor route and characterized with X-ray diffractometry (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), UV–vis spectroscopy, and Mössbauer spectroscopy. We find a red shift of 0.39 eV in the UV–vis spectrum and hence an improved photoelectrochemical activity in the visible range upon Fe doping in BaTiO 3 . The origin of the observed activity in the visible range is traced through the calculated electronic structure to the electronic states associated with Fe at energies within the band gap. A reasonable agreement between the changes in measured spectra and those in calculated electronic structure augurs well for a judicious use of first-principles calculations in screening of dopants in the design of doped oxide materials with enhanced photoelectrochemical activity, such as that of Fe-doped BaTiO 3 demonstrated here.