Optical and structural properties of solid oxide photocatalyst Bi₂FeNbO₇

Polycrystalline sample of Bi₂FeNbO₇ was synthesized by the solid-state reaction and characterized by powder x-ray diffraction and Rietveld structure refinement. The optical absorption and structural properties of Bi₂FeNbO₇ were investigated. It was found that the Bi₂FeNbO₇ compound has the pyrochlore crystal structure, cubic system with space group Fd3m, and the lattice parameter is a = 10.5233(2) Å. Ultraviolet-visible diffuse reflectance spectroscopy measurement revealed that the band gap of Bi₂FeNbO₇ is about 2.1(6) eV.