Fe Substituted SrTiO3 as Visible Light Active Photosensitive Material for Solar-Hydrogen Generation

Perovskite SrTiO3 and Fe Substituted SrTiO3 were prepared by solid-state reaction route as visible light active photosensitive materials for solar-hydrogen generation applications. Powder X-ray diffraction pattern confirms the formation of crystalline perovskite SrTiO3 phase at sintering temperature of 1273 K. The pattern of Fe substituted SrTiO3 exhibits number of peaks with splits and less crystalline indicating a lower symmetry structure upon substation at Sr and Ti sites. Crystallinity and crystallite size also finds decrease with increased Fe substitution. The band gap of SrTiO3 obtained by DR UV-Vis absorbance analysis at various sintering temperature approaches the theoretical value 3.06 eV. However, on Fe substitution the band gap is reduced to ~ 2.0-2.5 eV suggesting the materials can extend its absorption to the visible range also. FT-IR spectra confirmed that the Fe substituted SrTiO3 is similar to that of pure phase with bands corresponding to the hydroxyl and carboxyl groups. Since the substituted materials show reduced band gap, these materials can be utilized for photosensitive solar-hydrogen generation.