Tailoring Optical and Crystal Structural Properties of Bismuth Ferrite Based Nanomaterials via Ion Doping for Enhanced Photocatalytic Activity
Bismuth ferrite based Gadolinium (Gd) modified nano crystallite powder was synthesized by the hydrothermal method. The effects of Gd additive on the phase formation, crystal structure, optical properties, and photocatalytic performance were investigated. Crystal structure, crystallite size and phase formation were used to determine by X-ray diffraction (XRD) technique. Additionally, the structural phase formation was also studied by Raman spectroscopy. Average crystallite size, phase and peak analysis were determined using the X’ Pert High Score Plus program. According to the XRD peak pattern, it was determined that the structures of the synthesized sample was formed in the polycrystalline Bi25FeO40 (Sillenite) phase. The average crystallite sizes of 3 % Gd modified Bi25FeO40 sample was calculated as 50 nm. By using absorption edge data, the bandgap value was determined as 1.98 eV. Photocatalytic performance was evaluated in an environment where methylene blue was used as an organic pollutant, by UV-Vis spectrophotometer under a solar simulator. The photocatalytic efficiency was calculated as 70 %. Such a high efficiency was attributed to increased optical absorption, narrowing band gap, thereby, probably the efficient separation and migration of photogenerated charge carriers. It was concluded that although unintentionally formed Sillenite during synthesis of bismuth ferrite is useful for photocatalysis. Furthermore, it was pointed that the optical properties by means of crystal structure is able to be tailored by doping to increase the photocatalytic activity.