Synthesis, optical, and magnetic properties of six‐layered Aurivillius bismuth ferrititanate

• Published in: Journal of the American Ceramic Society 2019-06, Vol.102 (6), p.3555-3566
• Main Authors: Huang, Yanlin, Mi, Longqing, Qin, Jie, Bi, Shala, Seo, Hyo Jin
• Format: Article
• Language: English
• Subjects: Aurivillius phases; band structure; Bismuth; Catalysis; Conduction bands; Crystal structure; Electronic components; layered perovskites; Magnetic properties; Nanoparticles; Optical properties; Organic chemistry; Perovskites; Photocatalysis; Photodegradation; Rhodamine; semiconductors; Valence band
• ISSN: 0002-7820; 1551-2916
• DOI: 10.1111/jace.16226

This work reports on the preparation, structure, photochemical, and magnetic properties of six‐layered Aurivillius bismuth ferrititanates, that is, Bi7Ti3Fe3O21, Bi7(Ti2Nb)Fe3O21+δ, and Bi7(Ti2Mg)Fe3O21−δ nanoparticles. The samples were prepared through the modified citrate complexation and precursor film process. The XRD Rietveld refinements were conducted to study the phase formations and crystal structure. The morphological and chemical component characteristics were investigated using SEM, TEM, and EDX analyses. Bi7Ti3Fe3O21, Bi7(Ti2Nb)Fe3O21+δ, and Bi7(Ti2Mg)Fe3O21−δ nanoparticles present an indirect allowed transitions with band energies of 2.04, 2.03, and 2.02 eV, respectively. The hybridized (O2p+Fet2g+Bi6s) formed the valence band (VB) and electronic components of (Ti–3d+Fe–eg) formed the conduction band (CB) of this six‐layered Aurivillius bismuth ferrititanate. The three samples showed efficient photocatalytic degradation of Rhodamine B (RhB) dyes with the excitation wavelength λ > 420 nm. The optical absorption, photodegradation, and magnetic abilities were improved through microstructural modification on “B” site via partial substitution of Mg2+ and Nb5+ for Ti4+. The photocatalytic results were discussed based on the layer structure and multivalent Fe ions. Fe3+/2+ in the perovskite slabs (Bi5Fe3Ti3O19)2− could act as the catalytic mediators in the photocatalysis process. As a photocatalyst, Aurivillius Bi7(Ti2Mg)Fe3O21−δ nanoparticle is advantageous due to its photocatalytic and magnetically recoverable abilities.