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

Abstract

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.

Polyporous PVDF/TiO2 photocatalytic composites for photocatalyst fixation, recycle, and repair

“…UV-Vis diffuse reflectance spectra show the poor absorption of PVDF and strong absorption of TiO 2 powder in the UV A survey of the published literature modeling of CMCs has been studied by a n ers. Processes that have been modeled CVD, 17,18 CVI, [19][20][21][22] and Sol-Gel Infiltrat of alumina matrix in eight-harness satin has been studied numerically in Ref. [ proaches used in the above work general ing the flow of a high viscosity resin thr and modeling the chemical reactions and during processing.…”

“…Under the irradiation of Vis and UV, PVDF exhibits degradation to RhB, and degradation to RhB is much higher under A survey of the published literature shows that process modeling of CMCs has been studied by a number of researchers. Processes that have been modeled include RMI, 15,16 CVD, 17,18 CVI, [19][20][21][22] and Sol-Gel Infiltration. 23 Impregnation of alumina matrix in eight-harness satin Nextel 610 fabric has been studied numerically in Ref.…”

“…[14][15][16] For recycle, photocatalysts are modified to accelerate their self-deposition, or composited with magnetic materials. 8,10,[17][18] But when it comes to the practical application in an open and flowing environment, their fixation and recycle are unrealistic. Immobilizing catalysts on the surface of templates is a good solution, but sacrificing photocatalytic activity is inevitable.…”

Progress and Perspectives on Aurivillius-Type Layered Ferroelectric Oxides in Binary Bi4Ti3O12-BiFeO3 System for Multifunctional Applications

“…The ion substitution would influence the inter-strain and tolerance factor. The A-site can be occupied by large cations such as Na + [20], K + [107], Ca 2+ [108], Sr 2+ [46], Ba 2+ [26], Pb 2+ [109], Y 3+ [21], Bi 3+ and Ln (La [27], Nd [22], Sm [23], Gd [24], Ce [110][111][112],Tb [25], Dy [113], Ho [114], Er [115,116], Eu [56], Yb, Th [117], Pr [118]), the B-site can accommodate hetero-valent elements (Ti 4+ , W 6+ [36], Nb 5+ [43], Ta 5+ [119], V 5+ , Cu 2+ [120], Mo 6+ [121], and Mg 2+ [43]) and a variety of magnetic elements (Fe, Cr, Mn, Co, and Ni) [32][33][34][35][36][37][38][39][40][41][42][43][44]52], which will create the possibility of magnetic ordering. More interestingly, the halogen or nitrogen elements substitution on the O-sites was accomplished [122,123].…”

“…In the last decade, numerous pieces of research focused on the BFTO-n with integer n, for example, Bi 5 FeTi 3 O 15 , Bi 6 Fe 2 Ti 3 O 18 , and Bi 7 Fe 3 Ti 3 O 21 . The reported studies have mainly embodied two aspects: (i) doping ions into A-sites [19][20][21][22][23][24][25][26][27][28][29] and/or substituting magnetic transition ions into B-sites [30][31][32][33][34][35][36][37][38][39][40][41][42][43] inside the layered perovskite structure to realize a significant enhancement in the multiferroic performances, and (ii) controllable synthesis of materials in ceramics [44][45][46], thin films [47][48][49][50][51][52], nano-crystallines [53][54][55][56][57][58] and single crystals [59][60][61] to observe the growth process [62][63][64]…”