On Structure, Optical Properties and Photodegradated Ability of Aurivillius-Type Bi3TiNbO9 Nanoparticles

Bi3TiNbO9 nanoparticles with an acceptor dopant of Ni2+ ion were prepared by the conventional Pechini sol-gel synthesis. The X-ray polycrystalline diffraction measurements (XRD) and the Rietveld refinements of Bi3TiNbO9 samples were completed. The surface property of Bi3TiNbO9 nanoparticles was investigated by transmission electron microscope, scanning electron microscope), and N-2 adsorption-desorption isotherms. Bi3TiNbO9 nanoparticles showed an optical band gap with energy of 3.1 eV in the UV region. While the Ni2+-doping could greatly reduce the band energy of Bi3TiNbO9:xNi(2+) nanoparticles to 2.79 eV (x = 0.05) and 2.61 eV (x = 0.1). This indicates that the Ni-doped samples could be excited by UV-visible light. The photocatalytic abilities were tested by the photodegradation on methylene blue solution (MB) and phenol solutions excited by visible light. Accordingly, the photocatalytic activity was improved by the Ni-doping in B-sites in this Aurivillius-type structure. The results concluded that Bi3TiNbO9: Ni2+ would be a possible candidate as a visible light-driven photocatalyst. The effective photocatalysis was discussed on the structure characteristic and experiment such as polarized Aurivillius (Bi2O2)(2+) layers, luminescence, and decay lifetimes, etc.